The Sealed Attic System. with DuPont Tyvek AtticWrap INSTALLATION MANUAL

Transcription

1 The Sealed Attic System TM TM with DuPont Tyvek AtticWrap INSTALLATION MANUAL

2 TM DuPont Tyvek TM AtticWrap Revealed The sealed attic vented roof system uses DuPont TM Tyvek AtticWrap TM airtight membrane to establish an air barrier beneath the roof sheathing. The blue arrows indicate the path air follows from eave to ridge between the layer of Tyvek AtticWrap TM and the roof sheathing. Functioning as an air barrier, Tyvek AtticWrap TM helps prevent interior conditioned air from leaking into the attic by blocking air loss from the attic. Tyvek AtticWrap TM is vapor permeable so water vapor that reaches the attic from inside the house can diffuse through it and into the vent channels.

3 DuPont TM Tyvek AtticWrap TM Installation Manual CONTENTS Introduction 2 Science Behind Sealed Attic Vented Roof System 3 Benefits 5 Installation Overview 6 Safety 7 Installation Methods Furring Method 8 Rafter Cap Method 12 Drape Method 16 Common Details 20 Glossary 23 Frequently Asked Questions 24 Product Specifications 26

4 BUILDING TODAY FOR A BETTER TOMORROW At DuPont, we use science to develop innovative products that work together to create healthier, safer, more attractive and more environmentally-sustainable buildings and homes. With more than 75 research and development facilities around the world, we re focused on creating revolutionary new products to help today s builders, architects and contractors create structures that are stronger, safer, more comfortable and longer-lasting. From materials that can help a room withstand storm and blast impacts, to improved glass performance, durable wood alternatives and breathable barriers to seal the building envelope against moisture, mold and air penetration, DuPont has a blueprint for the future of construction. DuPont TM Tyvek is a true miracle of science. Made from very fine, high-density polyethylene fibers, DuPont TM Tyvek offers all the best characteristics of paper, film and fabric in one material. It has provided new dimensions of protection, security and safety for a wide variety of industries. DuPont continues to invent new products and techniques. Now, the DuPont TM Tyvek weatherization systems products include Tyvek HomeWrap, Tyvek CommercialWrap, Tyvek StuccoWrap, Tyvek DrainWrap TM, DuPont TM FlexWrap TM, DuPont TM StraightFlash TM, DuPont TM Tyvek Tape, DuPont TM Tyvek Fasteners, and our newest miracles of science, Tyvek AtticWrap TM and Tyvek ThermaWrap TM. Our specialist network is a national group of over 160 highly-trained field representatives available to assist customers with their installations. From the latest updates on building codes to on-site consulting and training, your local DuPont TM Tyvek Specialist will help make sure each installation is done right. Tyvek AtticWrap allows water vapor through while it repels bulk water. Above, the release liner is pulled back to reveal the integrated adhesive strip; at left, Tyvek AtticWrap is positioned on a roof prior to fastening.

5 SEALED ATTIC VENTED ROOF SYSTEM This installation guide contains information on the function, use and installation of the DuPont TM Tyvek AtticWrap TM membrane. Tyvek AtticWrap TM, along with other DuPont TM Tyvek products, can help improve the durability and energy efficiency of buildings by helping to control heat, moisture and air movement through the building envelope. Tyvek AtticWrap establishes an air barrier over the roof framing and eaves, and ties into Tyvek HomeWrap on the walls to create a whole-house weather seal Modern North American attic spaces are vented with exterior air. The exterior ventilation air is intended to dilute moisture vapor entering the attic through air leaks from inside the building. This helps reduce the chance of the moisture condensing on the roof sheathing and framing, which can lead to mold and rot. However, introducing exterior ventilation air into an attic can have some unintended negative side effects. Vent air can shortcut and circulate through insulation such as fiberglass and reduce its effectiveness through a process called wind wash. Vent air can also accelerate the leakage of conditioned air from inside the building. And in humid climates, external vent air can introduce moisture into the roof structure. Outside air travels through ceiling insulation, reducing the effective R-value Roof ventilation depends on hot air rising, but the draw pulls conditioned air through holes in the ceiling and partition walls Air escaping from inside the building introduces moisture into the roof structure, where it can condense on attic surfaces and lead to mold and rot Ventilation space between the membrane and the roof sheathing provides continuous eave-to-ridge air ventilation Tyvek AtticWrap cuts off the stack effect, which helps prevent interior-conditioned air from escaping Tyvek AtticWrap helps keep moisture introduced by ventilating air away from the roof structure and ceiling insulation 3

6 SEALED ATTIC VENTED ROOF SYSTEM continued The sealed attic vented roof system establishes an air barrier beneath the roof sheathing using DuPont TM Tyvek AtticWrap TM airtight membrane. Tyvek AtticWrap TM is applied over the roof rafters to create vent channels beneath the roof sheathing. This space provides continuous eave-to-ridge air ventilation to cool the roofing material and to help carry away moisture vapor. Functioning as an air barrier, Tyvek AtticWrap TM helps prevent interior conditioned air from leaking into the attic by blocking air loss from the attic. Tyvek AtticWrap TM is moisture permeable so moisture vapor that reaches the attic from inside the house can diffuse through it and into the vent channels. Tyvek AtticWrap TM is also water resistant and serves as a secondary drainage plane for the roof. In the event water leaks through the roofing material or flashings due to ice damming, damage, wear or improper installation, or from water driven up through the eave vents during a storm, Tyvek AtticWrap TM channels water through the vent space down to the eaves where it can drain. Tyvek AtticWrap TM helps provide back-up water intrusion protection in case of roof leaks, keeping the attic space and the inside of the home safe and dry. Wind Tyvek AtticWrap serves as a secondary drainage plane Semi-conditioned air is kept within attic space Air channel Metalized surface Sealed soffits and rafter bays Moisture diffuses into ventilation space Conditioned Air Conditioned Air The metalized surface on Tyvek AtticWrap helps reduce heat build up in the attic. Air channels beneath the sheathing cools the roofing materials. The sealed rafter bays drain roof leaks and wrapped eaves resist water intrusion in high-wind areas. Tyvek AtticWrap provides a secondary drainage plane for the roof. Moisture vapor that migrates into the attic diffuses through Tyvek AtticWrap and into the vent channels where it is carried away by exterior ventilation air. The airtight attic creates a dry, semi-conditioned space. 4

7 THE SEALED ATTIC SYSTEM WITH DUPONT TM TYVEK ATTICWRAP TM PROVIDES A WEALTH OF BENEFITS Helps cut overall cooling and heating costs Radiant heat gain in the attic during summer adds to cooling costs. The underside of DuPont TM Tyvek AtticWrap TM is layered with a radiantly reflective metalized material and the low emissivity of the surface reduces heat gain and keeps the attic cooler. During the heating season, the radiant layer reflects heat back into the attic and reduces heat loss. Regulates attic temperature An airtight attic seals in warm air during the winter. In the summer an airtight attic stays cooler because the cooling ventilation air circulates directly beneath the roof sheathing, while the Tyvek AtticWrap TM reflects the heat away from the attic. Tyvek AtticWrap TM also helps prevent insect pests, dust and pollen from entering the attic while still permitting moisture vapor to pass through and exit. The result is a semi-conditioned attic space suitable for storage without concern of contamination. Reduces energy use Because Tyvek AtticWrap TM creates an airtight attic, conditioned interior air is less likely to leak through the ceiling from the living space and into the attic. Air conditioning, heating equipment and ductwork installed in a sealed attic lose less energy as well. Improves insulation performance When conventional ventilation air moves through attic shortcuts and around attic insulation, it reduces the insulation s effectiveness and robs energy from the building. But a sealed attic helps stop adverse effects by eliminating air movement, resulting in improved insulation performance. Tyvek AtticWrap TM protects the installed R-value of attic insulation. Enhances roof ventilation air flow Tyvek AtticWrap TM keeps insulation from blocking off the ventilation air channel, which allows air to flow freely between the roof sheathing and membrane. The ventilation air dissipates moisture vapor that passes through Tyvek AtticWrap TM as it cools the roof. Channels moisture vapor Moisture vapor passes safely through Tyvek AtticWrap TM, so vapor that enters the attic from inside the living space can diffuse through the membrane and into the vent channel where it mixes with ventilation air and is carried away. Acts as a secondary weather barrier Roofs can leak due to ice damming, storm damage, improper or damaged flashings, or severe weather. Tyvek AtticWrap TM collects leaking water and channels it to the eaves where it can drain outside the building. In coastal, high wind and hurricane prone areas where rain can penetrate the attic through the soffits, Tyvek AtticWrap TM blocks water infiltration into the building and allows it to drain safely out of the house. Reduces chance of ice damming Ice dams form when snow on the roof melts and refreezes near the edge of the eaves. This can lead to roof leaks. Tyvek AtticWrap TM helps reduce ice dams by keeping the roof surface cold in two ways. First, it creates an airtight attic that prevents warm air from reaching the roof sheathing where it would accelerate melting. Second, the air channel created by Tyvek AtticWrap TM directs ventilation air directly beneath the roof, helping to keep it cold. Helps protect asphalt shingles The air channel created by Tyvek AtticWrap TM directs ventilation air directly beneath the roof sheathing. The ventilation air moves faster in the air channel than it does in a conventionally vented roof. Therefore, the moving air cools the roof sheathing and shingles, helping to protect the whole roof system. 5

8 OVERVIEW OF THREE PRIMARY DUPONT TM TYVEK ATTICWRAP TM INSTALLATION METHODS There are three basic installation methods for applying DuPont TM Tyvek AtticWrap TM : the Furring, the Rafter Cap and the Drape methods. With each method, DuPont TM Tyvek AtticWrap TM is applied over the roof rafters or trusses before the roof sheathing is installed. Each method creates vent channels beneath the roof sheathing between the rafters or trusses. Air flowing through the vent channels cools the roof surface and carries away moisture vapor that diffuses through the membrane. The vent channels also act as gutters to collect water that leaks through the roofing or flashings and to drain it out through the soffits. Each Tyvek AtticWrap TM installation method is described separately: Furring method, pp. 8-11; Rafter Cap method, pp ; and Drape method pp After reviewing all three methods, choose one that best suits your project. In some cases, more than one installation method will be appropriate and can be used on the same roof. Eave Details for Venting To create a sealed airtight attic, DuPont TM Tyvek AtticWrap TM must wrap around the eaves of the roof and be sealed to the housewrap such as DuPont TM Tyvek HomeWrap TM. There are numerous strategies you can use to seal Tyvek AtticWrap TM at the eaves and to the housewrap. With some strategies the Tyvek AtticWrap TM membrane wraps around the eaves, and with others, the membrane is slit and folded between rafter tails or terminated at the exterior wall line. Each detail is constructed to maintain a free flow of ventilation air and to drain water as well. The choice of which detail to use depends on the type of soffit, facia or eave vent used on the building. The Tyvek AtticWrap TM eave installation details are grouped together on the pages following each installation method. Many eave details have alternates showing rafter or truss tails with and without subfacias. Plan the air intake as well as water drainage when choosing an installation detail. It s important to permit a free-flow of ventilation air entering along the eave edge or soffit and into the vent channels. Some less common eave detail designs are included near the end of the guide. FURRING METHOD RAFTER CAP METHOD DRAPE METHOD 6

9 ROOF SAFETY While we have tried to include DuPont TM Tyvek AtticWrap TM sealing and eave venting details for most common roof configurations and obstructions, not every possibility is addressed. When constructing Tyvek AtticWrap TM details not described here, it is important to provide a clear ventilation air channel, to seal the membrane at penetrations and edges keeping it watertight and airtight, and to maintain the slope of the membrane to prevent water from ponding. Tyvek AtticWrap TM product information Tyvek AtticWrap TM comes in rolls 4 ft. 11 in. wide by 164 feet long with an integrated adhesive strip along the top edge. Successive sheets are overlapped 6 inches. One roll of Tyvek AtticWrap TM covers about 7 squares (700 sq. ft.) of roof area when using the Furring method of installation, and 6 squares (600 sq. ft.) using the Rafter Cap or Drape methods. General installation notes Tyvek AtticWrap TM is usually installed horizontally across rafters or trusses but can be installed vertically as well. Install roof sheathing after each horizontal course of Tyvek AtticWrap TM is applied. The sheathing acts as a work and walk surface to apply successive Tyvek AtticWrap TM courses from. The optimal installation crew size is 2 to 3 workers. Full rolls of Tyvek AtticWrap TM are bulky to work with. Precut Tyvek AtticWrap TM on the ground to make handling easier on the roof. Cut lengths of Tyvek AtticWrap TM 12 in. longer than the roof length when using the Furring installation method. Add an additional 3 in. per rafter or truss bay when using the Rafter Cap or Drape methods. For the purposes of this installation guide, we will use the terms rafter to refer to both rafters and fabricated roof trusses. In some instances we will refer to truss where trussed roof installation procedures differ from those roofs framed with rafters. Whenever you re working on the roof, you are at high-risk. Falls can result in serious injury, so it s essential that you adhere to highsafety standards while you are installing Tyvek AtticWrap TM. For your own safety and the safety of other workers, you should use fall protection suitable for the jobsite conditions. To find out more about a fall protection plan, refer to the OSHA safety regulations 29 CFR1926. Other good sources for fall protection guidance are the NAHB-OSHA Jobsite Safety Handbook and the NAHB-OSHA Scaffold Safety Handbook. Please remember that Tyvek AtticWrap TM is a durable membrane, but it is not intended to be walked or leaned on. It is not designed to support your weight between rafters. WHEN WORKING ON A ROOF, PLEASE FOLLOW THESE GUIDELINES: Always ask What if in every situation that is potentially unsafe. Do not walk on Tyvek AtticWrap TM or leave it rolled out on floors so others may walk on it. This represents a slipping hazard. Do not put your weight on the membrane once it s installed. It is not designed to support your weight. Take the time to evaluate each job for the safest and most expedient way to access the elevated work areas. Your fall protection plan will help you identify and avoid hazards on the site. Your regional OSHA office or local builder s association can help you draft your plan. The person developing your plan needs to know that: Lifelines and lanyards must have no less than 5000 lbs. breaking strength. The anchorage for those lifelines must be able to support 5000 lbs. The whole system of harness, lanyard, lifeline and anchor must be strong enough to withstand twice the impact energy of a worker free-falling a distance of 6 ft., or the free-fall distance permitted by the system, whichever is less. Use a complete rope and harness system made by a reputable manufacturer and follow the instructions carefully. There are more than two dozen types of scaffolds mentioned in OSHA s safety rules for construction. Read the instructions carefully. If you are using ladders, be sure to secure them at the top and bottom. Ladders need to extend 3 ft. above the landing to provide a safe handhold when getting on or off. Remember, there is no substitute for your own alertness and common sense. 7

10 DUPONT TM TYVEK ATTICWRAP TM INSTALLATION USING FURRING METHOD STEP ONE Furring strip Air flow Tyvek AtticWrap The Furring method is the simplest installation method for installing DuPont TM Tyvek AtticWrap TM. Air vent channels are created between the roof sheathing and the Tyvek AtticWrap TM membrane by applying furring strips (strips of wood 1 in. or thicker by 1 1 /2 in. or wider) on top of each rafter over the taut stretched membrane. Vent space continuity is easy to achieve at the eave edges, hips, valleys and ridges using this method. Installers should account for the extra thickness that the furring adds to the roof when planning facia boards, rake boards and other roof trim. Contractors building in high wind and seismic zones should check with an engineer or local building department before using the Furring method. The furring strips may diminish the rigidity of the roof sheathing diaphragm. The Rafter Cap or Drape installation methods may be better choices for these locales. The Furring method is compatible with any insulation type or installation method including direct contact. Preparation: Select the DuPont TM Tyvek AtticWrap TM eave detail you wish to use and install the required framing, including subfacias, wall nailers, soffit blocking and rafter blocking. Complete all framing work before installing Tyvek AtticWrap TM. WRAP TIP Sometimes the integrated adhesive strip doesn t bond completely in cold weather. After installation is complete, check joints from inside the attic and press loose areas to ensure a tight seal. Apply the eave course of Tyvek AtticWrap TM : Snap a chalk line parallel to the eave edge approximately 12 in. to 16 in. up from the rafter tails. Roll out a section of Tyvek AtticWrap TM with the integrated adhesive strip at the top, aligning the edge of the membrane with the chalk line. Pull the membrane taut and staple it to the tops of the rafters across the entire length of the roof. STEP TWO Align Tyvek AtticWrap TM to chalk line and fasten to the tops of the rafters Roll out the next course of Tyvek AtticWrap TM : Align the bottom edge of the roll with the dotted line on the top edge of the course below. Staple the membrane taut to the tops of rafters, but be sure to leave the bottom 6 in. loose for sealing. Lift the bottom edge of overlying course and peel the release liner from the integrated adhesive strip on the course beneath. Align bottom edge with dotted overlap line Press the layers of Tyvek AtticWrap TM together along the integrated adhesive strip to create an airtight seal. Remove release liner, press sheets together 8

11 STEP THREE Install furring strips over Tyvek AtticWrap TM : Next, apply a furring strip on top of each rafter starting at the end of the rafter tail and extending up to the dotted overlap line along the top of the Tyvek AtticWrap TM. Furring strips should be a minimum of 1 in. thick by a minimum of 1 1 /2 in. wide. Fasten each furring strip with 10d or longer common nails spaced approximately 12 in. apart or according to the local building code nailing schedule. STEP FOUR Install roof sheathing over furring strips: Snap a chalk line across the furring strips as a guide line for the top edge of the roof sheathing. Install roof sheathing following the local building code nailing schedule. STEP FIVE Install successive courses of Tyvek AtticWrap TM, furring strips and roof sheathing: Install the next course of Tyvek AtticWrap TM across the rafters, again aligning it with the dotted line on the course below. Seal the lower edge to the top of the course below using the integrated adhesive strip. Install a furring Nail furring strips over rafters Nail roof sheathing over furring strips Install successive courses of Tyvek AtticWrap TM strip on each rafter up to the integrated adhesive strip of the overlying course of Tyvek AtticWrap TM. Install roof sheathing over furring strips. Follow the same sequence until you reach the ridge. STEP SIX Wrap Tyvek AtticWrap TM over the ridge: Wrap the top course of Tyvek AtticWrap TM over the ridge and onto the other side. Seal the overlapping edge with DuPont TM Tyvek Tape. If the edge of the membrane overlaps less than 10 in. over the ridge, apply an additional sheet of Tyvek AtticWrap TM at least 20 in. wide over the ridge to protect this vulnerable area. Fold Tyvek AtticWrap TM over the ridge and over the membrane on the other side, then tape overlap STEP SEVEN Cut furring strips to top of ridge and sheath: Cut and install furring strips so that they end within 2 in. of the center of ridge board. Rip sheathing to leave an air slot at least 1 /2 in. wide at the ridge to exhaust the vent channels between Tyvek AtticWrap TM and the roof sheathing. Ridge vent caps the slot and permits ventilation air to exhaust. Install sheathing with air slot at least 1 1 /2 in. wide at ridge 9

12 FURRING INSTALLATION METHOD continued FURRING INSTALLATION METHOD HIP AND VALLEY DETAILS VALLEY STEP ONE Install valley liner: Line the valley from the top of ridge to the eave with a half width sheet of DuPont TM Tyvek AtticWrap TM. Staple the membrane taut into the valley center. STEP TWO Line valley with half width sheet of Tyvek AtticWrap TM Cross-lap Tyvek AtticWrap TM courses: Extend each Tyvek AtticWrap TM course through the valley center and onto the opposite roof plane by at least 12 in. Where the courses overlap, seal the top course of Tyvek AtticWrap TM to the bottom course with DuPont TM Tyvek Tape. STEP THREE Cross-lap Tyvek AtticWrap TM courses Attach furring strips to valley jack rafters: Cut and install furring strips over the valley jack rafters ending them 1 in. short of the valley center. This leaves a 2 in. air vent channel in the valley. Sheath over the furring and the 2 in. space. HIP STEP ONE Cross-lap Tyvek AtticWrap TM over the hip: Extend the sheets of Tyvek AtticWrap TM from adjacent roof planes so that they overlap at the hip by a minimum of 12 in. Tape the overlap joint with DuPont TM Tyvek Tape. Finish the cross-lap from both sides before installing furring strips. STEP TWO Cross-lap Tyvek AtticWrap TM courses over hip Install furring strips over hip jack rafters and sheathe: Cut and install furring strips on top of each jack rafter up to the hip rafter. Furring strips should extend to within 1 in. of the hip rafter. Cut and install roof sheathing leaving a gap of at least 1 1 /2 in. along the hip for an air slot to exhaust the vent channels. Ridge vent caps the hip slot and permits ventilation air to exhaust. It may be necessary to apply blocking to the tail of the hip rafter to support the edge of the roof sheathing. Blocks may also be installed to the hip rafter between jacks to support the edge of the sheathing. Fasten furring strips over hip jacks Nail furring strips over valley jack rafters 10

13 INTAKE VENT AND EAVE SEALING DETAILS - FURRING METHOD Install blocking and nailers before wrapping the eaves with DuPont TM Tyvek AtticWrap TM. Subfacias may be installed before or after Tyvek AtticWrap TM is applied. Wrap the membrane around the eave and back to the wall. Lap Tyvek AtticWrap TM over the housewrap by 6 in. and seal the joint with DuPont TM Tyvek Tape. Wrap Tyvek AtticWrap TM around the rafter tails and back to the wall VENTING DRIP EDGE EAVE DETAIL The Venting Drip Edge Eave details use specialty slotted drip edge as an air intake Venting drip edge Blocking Venting drip edge Nailer Leave 1 1 /2 in. space between facia and sheathing Wrap membrane over rafter, attach to blocking DuPont TM Tyvek Tape Solid soffit Leave 1 1 /2 in. space between facia and sheathing Wrap membrane over rafter and subfacia, attach to nailer DuPont TM Tyvek Tape Solid soffit SOFFIT VENTED EAVE DETAIL 1 Detail 1 uses a continuous soffit vent immediately behind the facia board as an air intake Blocking Standard drip edge Facia Nailer Standard drip edge Facia 5/4 in. x 2 in. spacer Continuous soffit vent Wrap membrane over rafter, attach to blocking DuPont TM Tyvek Tape Solid soffit 5/4 in. x 2 in. spacer Continuous soffit vent Wrap membrane over rafter and subfacia, attach to nailer DuPont TM Tyvek Tape Solid soffit SOFFIT VENTED EAVE DETAIL 2 Detail 2 uses a perforated soffit or any soffit vent product as an air intake Standard drip edge Facia Attach 5/4 in. x 2 in. spacers at rafter tail and along blocking Blocking Standard drip edge Facia Attach 5/4 in. x 2 in. spacers at rafter tails and blocking Nailer Wrap membrane over rafter, attach to blocking Wrap membrane over rafter and subfacia, attach to nailer Continuous ventilated soffit DuPont TM Tyvek Tape Continuous ventilated soffit DuPont TM Tyvek Tape WRAP TIP Full rolls of Tyvek AtticWrap TM are bulky to work with. Precut Tyvek AtticWrap TM on the ground to make handling easier on the roof. Cut lengths of Tyvek AtticWrap TM 12 in. longer than the roof length when using the Furring installation method. Add an additional 3 in. per rafter or truss bay when using the Rafter Cap or Drape methods. 11

14 DUPONT TM TYVEK ATTICWRAP TM INSTALLATION USING RAFTER CAP METHOD STEP ONE Rafter cap Air flow Tyvek AtticWrap The Rafter Cap method uses U shaped plastic channels designed to fit tight over the top of rafters. DuPont TM RafterCap creates air vent channels by holding Tyvek AtticWrap TM taut between the rafters about 1 1 /2 in. below the roof sheathing. Tyvek AtticWrap TM wrinkles and bunches where the surface plane of the roof changes at rafter tails, hips, valleys and ridges. Extra care must taken when detailing the membrane at these areas to maintain open vent channels. Apply the eave course of Tyvek AtticWrap TM : Pre-cut one 6 in. piece of DuPont TM RafterCap for each rafter tail. Snap a chalk line parallel to the eave edge approximately 12 in. to 16 in. up from the rafter tails. Roll out about 6 ft. of Tyvek AtticWrap TM with the integrated adhesive strip at the top. Align the top edge of the membrane with the chalk line and staple the end of the sheet to the first rafter. As one worker unrolls the Tyvek AtticWrap TM, a second worker places a rafter cap over each rafter. Nail or staple the rafter caps securely to the rafters. Keep the membrane taut between rafters and aligned with the chalk line. Do not place the rafter caps above the dotted overlap line at the top of the sheet. The Rafter Cap method can be combined with the Drape method during installation. The Rafter Cap method is compatible with any type of insulation, including direct contact, provided the Tyvek AtticWrap TM membrane is taut between rafters. Preparation: Select the Tyvek AtticWrap TM eave detail you wish to use. Install the required framing, including subfacias, wall nailers, soffit blocking and rafter blocking. DuPont TM RafterCap holds Tyvek AtticWrap TM taut between rafters STEP TWO Staple the rafter caps to the rafters Apply a full course of Tyvek AtticWrap TM : After completing the eaves course, begin the first full course with the bottom edge of the roll aligned with the dotted line on the course below. Slide a full length DuPont TM RafterCap over the Tyvek AtticWrap TM and rafter, centering the rafter caps between the overlap lines printed on Tyvek AtticWrap TM. Again nail or staple the rafter caps to the rafters to hold them securely in place. Fasten the rafter caps to the rafters 12

15 STEP THREE Seal Tyvek AtticWrap TM layers: Lift the bottom edge of overlying course and peel the release liner from the integrated adhesive strip on the course beneath. Press the layers of Tyvek AtticWrap TM together along the integrated adhesive strip to create an airtight seal. STEP SIX Wrap Tyvek AtticWrap TM over the ridge: Wrap the top course of Tyvek AtticWrap TM over the ridge and onto the other side. Seal the overlapping edge with DuPont TM Tyvek Tape. If the edge of the membrane overlaps less than 10 in. over the ridge, apply an additional sheet of Tyvek AtticWrap TM at least 20 in. wide over the ridge to protect this vulnerable area. Cut and install short pieces of rafter cap over the ridge between the rafters to prevent loose Tyvek AtticWrap TM from blocking the vent channels. Seal the layers of Tyvek AtticWrap TM together STEP FOUR Install roof sheathing over rafter caps: Snap a chalk line across the rafter caps as a guide line for the top edge of the roof sheathing. Install roof sheathing following the local building code nailing schedule. STEP FIVE Install roof sheathing over rafter caps Install successive courses of Tyvek AtticWrap TM and roof sheathing: Install the next course of Tyvek AtticWrap TM using rafter caps. Align the membrane with the dotted overlap line on the previous course. Seal the joint between the layers with the integrated adhesive strip and cover with roof sheathing. Continue the sequence until you reach the ridge. Work off the roof sheathing to install successive Tyvek AtticWrap TM courses Fold Tyvek AtticWrap TM over the ridge and tape overlap STEP SEVEN Leave vent slot at ridge: Rip sheathing to leave an air slot at least 1 1 /2 in. wide at the ridge to exhaust the vent channels between Tyvek AtticWrap TM and the roof sheathing. Ridge vent covers the slot and permits ventilation air to exhaust. Nail on sheathing ripped to provide a 1 1 /2 in. vent slot WRAP TIP If the roof pitch is greater than 5:12, install toeboards or roof staging along the roof sheathing as required by safety regulations. 13

16 RAFTER CAP INSTALLATION METHOD continued FURRING INSTALLATION METHOD HIP AND VALLEY DETAILS Valleys can be vented two different ways. The valley rafter can be dropped by 2 in. to create a vent channel or the valley jacks can be vented laterally to an adjacent common rafter bay by applying DCI Products TM ValleyVent over the lower portion of each jack. DROPPED VALLEY RAFTER VENTING METHOD STEP ONE Drop valley rafter: Cut the valley rafter seat an additional 2 in. deep so the valley rafter rests lower. Use a 2 in. spacer block to gauge the valley jack installation. VALLEYVENT VENTING METHOD STEP ONE Install Tyvek AtticWrap TM through valley: Cross-lap the two sheets of Tyvek AtticWrap TM meeting at the valley by 12 in. minimum. Leave enough slack in each layer to install rafter caps over the jacks. STEP TWO Apply rafter caps to jacks: Apply a DuPont TM RafterCap over each valley jack. Tape the end of the Tyvek AtticWrap TM sheet to seal the joint. Drop valley rafter lower than jacks STEP TWO Install Tyvek AtticWrap TM through valley: Cross-lap the two sheets of DuPont TM Tyvek AtticWrap TM meeting at the valley by 12 in. minimum. Leave enough slack in each layer to install the DuPont TM RafterCap. STEP THREE Cap jack and valley rafters: Apply a 1 /8 in. to 1 /4 in. strip of wood or plastic on top of the valley rafter to hold the Tyvek AtticWrap TM in position and keep the vent space open. Install rafter caps over the valley jacks and staple any loose Tyvek AtticWrap TM to the rafters. Seal the cross-lap joints with DuPont TM Tyvek Tape. STEP THREE Apply rafter caps over valley jacks Install ValleyVent and sheath: Apply DCI Products TM ValleyVent at the bottom of each valley jack. Place the thick (three ply) end of ValleyVent to the valley rafter and nail in position. Apply roof sheathing over the valley jacks and ValleyVent. Apply DCI Products TM ValleyVent over jacks before installing roof sheathing Apply rafter caps over valley jacks 14

17 Wrap Tyvek AtticWrap TM around the rafter tails and back to the wall HIP RAFTER VENTING METHOD STEP ONE Cross-lap Tyvek AtticWrap TM over hip: Cross-lap courses of DuPont TM Tyvek AtticWrap TM a minimum of 12 in. across hip. Leave enough slack in each layer to install rafter caps. INTAKE VENT AND EAVE SEALING DETAILS - RAFTER CAP METHOD Install blocking and nailers before wrapping the eaves with DuPont TM Tyvek AtticWrap TM. Wrap the membrane around the eave and back to the wall. Lap Tyvek AtticWrap TM over the housewrap by 6 in. and seal the joint with DuPont TM Tyvek Tape. With soffit vented eave details, clinch staple the loose Tyvek AtticWrap TM between the rafter tails to prevent air channels from being closed off. VENTING DRIP EDGE EAVE DETAIL The Venting Drip Edge Eave details use specialty slotted drip edge as an air intake Venting drip edge Blocking STEP TWO Overlay Tyvek AtticWrap TM from second roof plane onto the first plane Install rafter caps: Cut and install DuPont TM RafterCap over the jack rafters. Install short pieces of rafter caps over the hip rafter between the jacks and inset staple any loose Tyvek AtticWrap TM to prevent it from blocking the vent channel. Tape Tyvek AtticWrap TM joints with DuPont TM Tyvek Tape. STEP THREE Install roof sheathing: Cut and install roof sheathing up to the hip. Leave a 1 1 /2 in. minimum air slot between the panel edge and the hip rafter to exhaust the vent channels. Install blocking to hip rafter to support panel edges if needed. Cut the bottom sheathing panels so the lower one foot laps over the hip rafter for support. Ridge vent will cap the vent slot and permit ventilation air to exhaust. Apply rafter caps over jacks Leave 1 1 /2 in. space between facia and sheathing Wrap membrane over rafter, attach to blocking DuPont TM Tyvek Tape Leave 1 1 /2 in. space between facia and sheathing Venting drip edge Wrap membrane over rafter and subfacia, attach to nailer Subfacias may be installed before or after Tyvek AtticWrap TM is applied SOFFIT VENTED EAVE DETAIL The Soffit Vented Eave details use soffit vents or perforated venting soffit Standard drip edge Facia Wrap membrane over rafter, attach to blocking Standard drip edge Facia Continuous ventilated soffit DuPont TM Tyvek Tape Install subfacias after Tyvek AtticWrap is applied Wrap membrane over rafter, attach to nailer Continuous ventilated soffit DuPont TM Tyvek Tape DuPont TM Tyvek Tape Solid soffit Nailer Solid soffit Blocking Nailer 15

18 DUPONT TM TYVEK ATTICWRAP TM INSTALLATION USING DRAPE METHOD Air flow Tyvek AtticWrap drapes between rafters We recommend that the first two courses of DuPont TM Tyvek AtticWrap TM be installed with DuPont TM RafterCaps when following the Drape method of installation. Refer to rafter cap steps 1-4 on pp The steps for installing the Drape method using the inset stapling technique instead of rafter caps are described in steps 1-5 on pp Where insulation comes in contact with Tyvek AtticWrap TM, rafter caps or inset stapling are necessary to prevent the air vent channels from being closed off. STEP ONE The Drape method requires no additional materials like furring strips or rafter caps to be installed. Tyvek AtticWrap TM is draped between rafters leaving about a 1 1 /2 in. space below the tops of the rafters. Using a jig, the Drape method can be the fastest to install; however, the eave, hip and valley details can be more time consuming than the Furring or Rafter Cap methods. When using the Drape method, extra care must be taken to prevent the attic insulation from pressing against the draped Tyvek AtticWrap TM and closing off the vent channels. This situation is most likely to occur along the exterior wall plates or anywhere insulation comes into contact with draped Tyvek AtticWrap TM. To prevent this problem, we recommend that rafter caps be installed 4 ft. up each rafter from the eave edge and in any other locations where insulation may be installed in contact with Tyvek AtticWrap TM such as above knee walls. Short pieces of rafter caps can also be installed over ridge boards, hip rafters and the ends of valley and hip jacks to prevent loose Tyvek AtticWrap TM from blocking exhaust vents. Apply the eave course of Tyvek AtticWrap TM : Snap a chalk line parallel to the eave edge approximately 12 in. to 16 in. up from the rafter tails. Roll out about 6 ft. of Tyvek AtticWrap TM with the adhesive layer at the top. Align the top edge of the membrane with the chalk line and staple the end of the sheet to the first rafter. Drape the membrane 1 /2 in. to 2 in. between rafters, using a small spacing jig to achieve a consistent drape. Staple Tyvek AtticWrap TM to the top of rafters, then inset staple the membrane to the inside edges of the rafters 1 /2 in. to 2 in. down from the top. Space staples 2 in. to 3 in. apart. Inset stapling keeps the Tyvek AtticWrap TM taut between 1 1 /2 in. to 2 in. drape depth the rafters and keeps the air vent channels from being closed off when insulation is installed. Use jig to gauge drape depth Preparation: Select the Tyvek AtticWrap TM eave detail you wish to use and install the required framing including subfacias, wall nailers, soffit blocking and rafter blocking. Complete all framing work before installing Tyvek AtticWrap TM. 2x2 13 in. long for 16 in. OC spacing, 21 in. for 24 in. OC spacing 2x3 18 in. long for 16 in. OC spacing, 26 in. for 24 in. OC spacing Build drape jig from blocks cut on the jobsite 16

19 STEP TWO Apply a full course of Tyvek AtticWrap TM : After completing the eaves course, begin the first full course with the bottom edge of the roll aligned with the dotted line on the course below. Staple the top corner and roll out about 6 ft. of Tyvek AtticWrap TM across the rafters. Use a multi-block spacing jig for consistent drapes between rafters and to speed the installation process (previous page). Staple Tyvek AtticWrap TM to the top of the rafters and inset staple 3 ft. in from the exterior wall. Be sure to leave the bottom 6 in. loose for sealing. Use cap nails or cap staples during windy conditions to prevent Tyvek AtticWrap TM from being blown loose. Drape Tyvek AtticWrap TM between rafters with multi-block jig STEP THREE Seal Tyvek AtticWrap TM layers: Lift the bottom edge of overlying course and peel the release liner from the integrated adhesive strip on the course beneath. Press the layers of Tyvek AtticWrap TM together along the integrated adhesive strip to create an airtight seal. STEP FOUR Install roof sheathing: Snap a chalk line across the Tyvek AtticWrap TM as a guide line for the top edge of the roof sheathing. Install roof sheathing following the local building code nailing schedule. Seal the layers of Tyvek AtticWrap TM together Install roof sheathing over draped Tyvek AtticWrap TM 1 /2 in. plywood strip 18 in. long x 1 1 /2 in. attached to 2x2 blocks 13 in. wide 3 ft. 2x2 STEP FIVE Drape successive courses of Tyvek AtticWrap TM : Drape the next course of Tyvek AtticWrap TM across the rafters. Align the membrane with the dotted overlap line on the previous course and fasten. Inset stapling is not necessary unless insulation will come in direct contact with the membrane. Seal the joint between layers with the integrated adhesive strip and cover with roof sheathing. Continue the sequence up to the ridge. Assemble a simple multi-block drape jig from jobsite scraps Install successive courses of Tyvek AtticWrap TM with multi-block drape jig 17

20 DRAPE INSTALLATION METHOD continued STEP SIX Wrap Tyvek AtticWrap TM over the ridge: Wrap the top course of Tyvek AtticWrap TM over the ridge and onto the other side. Seal the overlapping edge with DuPont TM Tyvek Tape. If the edge of the membrane overlaps less than 10 in. over the ridge, apply an additional sheet of Tyvek AtticWrap TM at least 20 in. wide over the ridge to protect this vulnerable area. Install short pieces of rafter cap over the ridge board (see pp. 13, step six) or inset staple to the ridge board to prevent loose Tyvek AtticWrap TM from blocking the ridge vent. Inset staple Tyvek AtticWrap TM to the ridgeboard and seal the overlap with DuPont TM Tyvek Tape Valleys can be vented two different ways. The valley rafter can be dropped by 2 in. to create a vent channel or the valley jacks can be vented laterally to an adjacent common rafter bay by applying DCI Products TM ValleyVent over the lower portion of each jack. DROPPED VALLEY RAFTER VENTING METHOD STEP ONE Drop valley rafter: Cut the valley rafter seat an additional 2 in. deep so the valley rafter rests lower. Use a 2 in. spacer block to gauge the valley jack installation. Valley dropped 2 in. to create air channel for venting jack bays STEP TWO Install Tyvek AtticWrap TM through valley: Cross-lap the two sheets of Tyvek AtticWrap TM meeting at the valley by 12 in. minimum. Leave enough slack in the membranes to inset staple. STEP SEVEN Leave vent slot at ridge: Rip sheathing to leave an air slot at least 1 1 /2 in. wide at the ridge to exhaust the vent channels between Tyvek AtticWrap TM and the roof sheathing. Ridge vent covers the slot and permits ventilation air to exhaust. STEP THREE Inset staple jack and valley rafters: Apply a 1 /8 in. to 1 /4 in. strip of wood or plastic on top of the valley rafter to hold Tyvek AtticWrap TM in position and keep the vent space open. Inset staple the membrane to the valley jacks and valley rafter. When available, install pieces of rafter caps where the valley jacks meet the valley rafter. Tape seams of the the Tyvek AtticWrap TM cross-laps with DuPont TM Tyvek Tape. Install and nail roof sheathing at ridge Apply a strip of wood or plastic on top of the valley rafter to hold Tyvek AtticWrap TM in position and keep the vent space open 18

21 VALLEYVENT VENTING METHOD STEP ONE Install Tyvek AtticWrap TM through valley: Cross lap the two sheets of Tyvek AtticWrap TM meeting at the valley by 12 in. minimum. Leave enough slack in the membranes to inset staple. HIP DRAPE METHOD STEP ONE Cross-lap Tyvek AtticWrap TM over the hip: Cross-lap the two sheets of Tyvek AtticWrap TM meeting at the hip by 12 in. minimum. Leave enough slack in the membranes to inset staple. STEP TWO Inset staple Tyvek AtticWrap TM to jacks and valley rafter: Inset staple Tyvek AtticWrap TM to the valley rafter and bottom 12 in. of each valley jack. When available, install pieces of rafter caps where the valley jacks meet the valley rafter instead of inset stapling. Tape the end of the Tyvek AtticWrap TM sheet to seal the joint. STEP TWO Inset staple Tyvek AtticWrap TM : Inset staple Tyvek AtticWrap TM to the hip rafter and the top 12 in. of each jack rafter. When available, install short pieces of rafter caps over the hip rafter between the jacks and at the end of the jacks instead of inset stapling. Seal Tyvek AtticWrap TM joints with DuPont TM Tyvek Tape. Inset staple Tyvek AtticWrap TM to hip and jack rafters Inset staple Tyvek AtticWrap TM to jack rafters STEP THREE Install ValleyVent and sheath: Apply DCI Products TM ValleyVent at the bottom of each valley jack. Position the thick (three ply) end of ValleyVent to the valley rafter and fasten it in place. Apply roof sheathing over the valley jacks and ValleyVent. Apply DCI Products TM ValleyVent at the bottom of valley jacks STEP THREE Install roof sheathing: Cut and install roof sheathing up to the hip. Leave a 1 1 /2 in. minimum air slot between the panel edge and the hip rafter to exhaust the vent channels. Install blocking to hip rafter to support panel edges if needed. Cut the bottom sheathing panels so the lower one foot laps over the hip rafter for support. Ridge vent will cap the vent slot and permit ventilation air to exhaust. Install sheathing at hip to create vent slot 19

22 Wrap Tyvek AtticWrap TM around the rafter tails and back to the wall INTAKE VENT AND EAVE SEALING DETAILS - DRAPE METHOD Install blocking and nailers before wrapping the eaves with DuPont TM Tyvek AtticWrap TM. Wrap the membrane around the eave and back to the wall. Inset staple the membrane taut between the rafter tails. Lap Tyvek AtticWrap TM over the housewrap by 6 in. and seal the joint with DuPont TM Tyvek Tape. With soffit vented eave details, clinch staple the loose Tyvek AtticWrap TM between the rafter tails to prevent air channels from being closed off. VENTING DRIP EDGE EAVE DETAIL The Venting Drip Edge Eave details use specialty slotted drip edge as an air intake Venting drip edge Leave 1 1 /2 in. space between facia and sheathing Wrap membrane over rafter, attach to blocking Leave 1 1 /2 in. space between facia and sheathing Venting drip edge DuPont TM Tyvek Tape Blocking Solid soffit Nailer COMMON DETAILS USING DUPONT TM TYVEK ATTICWRAP TM NON-HEATING PIPE AND DUCT PENETRATION DuPont TM Tyvek AtticWrap TM can be directly sealed to pipes or ducts that penetrate the roof plane and do not carry heated exhaust. Some examples are: bathroom exhaust duct, plumbing vent stack, evaporator condensate drain, and electrical conduit. Cut an X slightly larger than the pipe or duct in Tyvek AtticWrap TM where it will penetrate the roof. Install the pipe or duct. Lift the membrane towards the roof sheathing and tape it to the pipe or duct with DuPont TM Tyvek Tape. This will help drain water around the penetration should the roof leak above it. Cut an X into Tyvek AtticWrap TM slightly larger than the pipe or duct Wrap membrane over rafter and subfacia, attach to nailer Subfacias may be installed before or after Tyvek AtticWrap TM is applied DuPont TM Tyvek Tape Solid soffit Tape Tyvek AtticWrap TM to the pipe or duct SOFFIT VENTED EAVE DETAIL The Soffit Vented Eave details use soffit vents or perforated venting soffit Standard drip edge Facia Wrap membrane over rafter, attach to blocking Continuous ventilated soffit DuPont TM Tyvek Tape Standard drip edge Blocking Nailer METAL HEATING EXHAUST PIPE Tyvek AtticWrap TM should not be attached directly to metal pipes that exhaust heating appliances. A 4 in. wide (minimum) collar should be affixed to the duct just beneath the rafter plane. Screw and seal the collar with an intumescent elastomeric firestop sealant to the pipe. Tape Tyvek AtticWrap TM to the metal collar to create an air seal. Facia Install subfacias after Tyvek AtticWrap is applied 20 Wrap membrane over rafter, attach to nailer Continuous ventilated soffit DuPont TM Tyvek Tape Seal Tyvek AtticWrap TM to the metal collar or exhaust duct

23 GABLE END (RAKE WALL) Tape DuPont TM Tyvek AtticWrap TM to the housewrap, such as DuPont TM Tyvek HomeWrap, at gable ends. Lap Tyvek AtticWrap TM over the gable end rake wall and seal to the housewrap with DuPont TM Tyvek Tape. If the housewrap extends above the roof line, overlap the Tyvek AtticWrap TM and tape along the gable rafter or top of the rake wall. Tape Tyvek AtticWrap TM to housewrap along gable end GABLE END (WITH RAKE OVERHANG) There are two methods to seal Tyvek AtticWrap TM to housewrap on walls with rake overhangs. 1: Wrap the entire overhang in a similar fashion to wrapping rafter tails. 2: Cut Tyvek AtticWrap TM at each horizontal block supporting the overhang and wrap the membrane between them. Cut Tyvek AtticWrap TM and tape between horizontal framing to the housewrap VERTICAL JOINTS IN TYVEK ATTICWRAP TM Overlap vertical joints in Tyvek AtticWrap TM by a minimum of one rafter bay and two rafters. This ensures a mechanical connection as well as a taped joint. Seal the joint with DuPont TM Tyvek Tape. Overlap vertical joints in Tyvek AtticWrap TM by a minimum of one rafter bay and two rafters ROOF TO SIDEWALL Lap Tyvek AtticWrap TM up onto sidewalls by a minimum of 6 in. and staple. Lap housewrap over the Tyvek AtticWrap TM. Leave the bottom edge of the housewrap loose to insert roof flashing later. Lift up housewrap and staple Tyvek AtticWrap TM to wall SKYLIGHT OPENING 1 Skylight openings cut into the roof after Tyvek AtticWrap TM and roof sheathing are applied require extra detailing. There are no provisions with this detail for cross-ventilation of rafter bays that dead-end at the skylight. Cut the skylight opening in the roof sheathing. X cut Tyvek AtticWrap TM and fold the flaps out onto the roof sheathing Seal the Tyvek AtticWrap TM edges to the roof sheathing using DuPont TM Tyvek Tape or seal with elastomeric caulk and staple SKYLIGHT OPENING 2 Trim the flaps so in. of Tyvek AtticWrap TM folds onto the surface of the roof sheathing Tape pieces of Tyvek AtticWrap TM at the corners to fill the void in the membrane Skylight openings framed before Tyvek AtticWrap TM and the roof sheathing are installed are the easiest to prepare. X cut out Tyvek AtticWrap TM in the skylight opening Apply a 3 ft. length of DCI Products TM RafterVent over each cripple rafter and trimmer rafters beginning 6 in. above and below the skylight opening to provide cross-ventilation between rafter bay air channels Fold the flaps back over the rafters and headers, staple and trim excess membrane Apply sealant around the perimeter of opening and bed the roof sheathing into it to form an airtight seal Install and flash the skylight following manufacturer s instructions 21

24 COMMON DETAILS USING DUPONT TM TYVEK ATTICWRAP TM continued MASONRY CHIMNEY CONNECTION DuPont TM Tyvek AtticWrap TM should not be attached directly to masonry chimneys. A 4 in. wide metal flashing or a metal collar should be affixed just beneath the rafter plane to the masonry. Install using masonry screws and seal with an intumescent elastomeric firestop sealant to the masonry. Apply sealant where collar meets masonry 4 in. wide metal flashing or a metal collar ROOF TO FACE WALL (VERTICAL WALL) Tape Tyvek AtticWrap TM to the metal collar to create an air seal Where rafters terminate at a wall (as in the case of a shed roof) the air vent channels should be vented. Use a vent product such as DCI Products TM SmartVent. Install according to manufacturer s instructions. Lap housewrap over Tyvek AtticWrap TM ALTERNATE EAVE DETAILS There are numerous ways to seal the eaves with Tyvek AtticWrap TM and provide ventilation air intake. Several common details follow each intallation method. The following details depict the Rafter Cap method of installation and can be modified to suit the Furring and Drape methods. Install Tyvek AtticWrap TM flush with the end of the rafter tails but do not install rafter caps or staple the membrane to the rafters beyond the exterior wall line Vented soffit Tape the bottom edge of Tyvek AtticWrap TM to the housewrap Fold the Tyvek AtticWrap TM flaps down to wall and embed in sealant Cut Tyvek AtticWrap TM at the centerline of each rafter or truss up to the line of wall sheathing Extend wall sheathing above plate to in. below top of rafters (or to the top of the rafters when using the Furring method) Run a bead of elastomeric sealant on both sides of each rafter where it meets the wall sheathing Exposed Rafter Tails Some styles of eave framing leave the rafter tails exposed. Solid blocking installed between the rafters closes off the rafter bays. Rip framing lumber for solid blocking 1 in. narrower than the space between the wall plate and the top of the rafter. Cut and install solid blocking between rafters. Cut and install vent strip, 1 in. thick by 1 /2 in. wide, over the top of the blocking. Install roof sheathing. Vent strip Tyvek AtticWrap TM bedded into sealant on blocks and sides of rafters Flashing Vent Lap Tyvek AtticWrap TM up and onto the wall by a minimum of 6 in. and staple Install the roof sheathing leaving a in. air space to vertical wall Rip bevel on blocks to match roof pitch Install the membrane flush with the blocks Seal block to framing with caulking Vent strip Tyvek AtticWrap TM bedded into sealant on blocks and sides of rafters Rip blocks to fit Seal block to framing with caulking 22

25 GLOSSARY OF TERMS Air Tight: A condition by which the perimeter of a space is enclosed to minimize the air movement into or out of the space. Air Vent Channel / Vent Channel / Air Channel / Vent Space: These four phrases are used to identify the space bordered by the rafters and in-between the underside of the roof sheathing and the DuPont TM Tyvek AtticWrap TM. Air flows into the space at eave vents and follows the space up to the exhaust vent. Cap Nails / Cap Staples: A fastener with a broad (1 in. or greater) plastic or metal disc that increases the contact area to increase wind resistance to pulling out. Diffusion: The flow of water vapor trough a building component, caused by the vapor pressure difference across the two sides of a component. Eave: The edge of a steep roof that may or may not project beyond the supporting wall. The eave may be covered by roof sheathing, a facia and soffit. Furring Strip: For the purposes of this guide, a furring strip is a strip of lumber minimum of 1 in. thick by 1 /2 in. located over each roof rafter and applied after Tyvek AtticWrap TM is installed over the rafters. Furring strips are nailed to the roof rafters and they create the vent space between Tyvek AtticWrap TM and the roof sheathing. Integrated Adhesive Strip: A 2 in. wide strip of adhesive pre-applied to Tyvek AtticWrap TM and covered by a plastic release liner. When the release liner is removed, the sealant can bond to the underside of the overlying sheet of Tyvek AtticWrap TM forming an airtight seal. Local Building Code: The building code that is enforced in the jurisdiction where building is located. Membrane: Typically a water resistive sheet, a term used interchangeably with Tyvek AtticWrap TM. Radiant Barrier: A surface that reflects 99% or more of the radiant energy back towards the energy source. Radiantly Reflective: A low emissivity surface that reflects most of the radiant energy back towards the energy source. Rafter Cap: A thin U-shaped channel that fits tightly over a rafter or truss. DuPont TM RafterCap is used to set the Tyvek AtticWrap TM plane 1 1 /2 in. below the decking to create the air space for venting and drainage. Ridge Vent: A class of roof vent products that is applied over a slot in the roof sheathing left along the ridge or hip of a house and permits air and water vapor to exhaust. Sealed Attic: An attic designed to eliminate (or minimize) the air flow into and out of the attic. Subfacia: Solid lumber applied over the face of the rafter tails that serves as a base to apply facia and soffit boards. Common subfacia materials are 2x4 or 2x6. Venting / Ventilation: The process of air flowing through the vent channel between the roof sheathing and the Tyvek AtticWrap TM that carries away moisture vapor and heat. Typically this is free air flow, not assisted mechanically by fans or blowers. 23

26 FREQUENTLY ASKED QUESTIONS FOR THE SEALED ATTIC SYSTEM USING DUPONT TM TYVEK ATTICWRAP TM Can I achieve a Sealed Attic by simply putting Tyvek AtticWrap on top of the roof sheathing? The Sealed Attic System relies on providing a method for attic moisture vapor release through the Tyvek AtticWrap TM membrane and into an active air space. This cannot be accomplished with the Tyvek AtticWrap TM installed over the roof deck because conventional decking, such as OSB and plywood, does not provide adequate moisture vapor flow through. Does the Sealed Attic System with Tyvek AtticWrap work in all regions and climates? Yes. The Sealed Attic System work in all regions and climates, controlling moisture within the attic space and improving the thermal performance of the entire roof. How does the Sealed Attic System work in hot and cold areas? In both climates, the sealed attic eliminates outside airflow into the attic space. The attic temperature then tends to approach the temperature of the living space rather than the outside temperature. The heat flow between the attic and the living space is therefore reduced along with the utility cost. In a hot climate, the metalized low-e surface of the Tyvek AtticWrap TM membrane works as a radiant barrier, cutting down the radiant heat transfer from the shingles into the attic space, keeping the attic cool. In turn, this heat reflection by Tyvek AtticWrap TM increases the speed of the venting air in the channel right beneath the roof sheathing, which helps to cool down the OSB, felt and shingles. This overall reduction of the heat load from the roof cuts down the air conditioning needs of the home. In a cold climate, the metalized reflective surface of the Tyvek AtticWrap TM membrane reflects the radiant heat rising from the ceiling back into the attic space. This keeps the attic warmer and helps reduce the energy loss through the roof. By increasing the attic temperature, the Sealed Attic System with DuPont TM Tyvek AtticWrap TM helps prevent condensation, mold and rot inside the attic. Why is the metalized surface of Tyvek AtticWrap installed facing down, to the inside of the attic space? This is to keep the surface shinny by helping prevent dust accumulation on the reflective low-e surface. A Sealed Attic System with a metalized surface facing down to the inside of the attic is the best practical solution for keeping the thermal performance of the low-e surface effective over time. Which installation method is preferred (furring strips, rafter caps, or drape)? DuPont has developed three practical methods to accomplish a Sealed Attic System with DuPont TM Tyvek AtticWrap TM. The selection of one method vs. another will be influenced by the builder s preference, local framing practices and local code compliance requirements. Is the Sealed Attic System with Tyvek AtticWrap applicable to all types of new residential roof designs that include valleys, dormers, hips and chimneys? Yes. The Sealed Attic System is applicable to all types of new residential roof designs, no matter the roof size and complexity. DuPont has developed extensive installation instructions to deal with the complexity of most roofing details such as valleys, hips, dormers and chimneys. Can I use Tyvek AtticWrap installation details not described in the installation guide? Yes. There are too many roof configurations to show all in one installation guide. When using any detail to install Tyvek AtticWrap TM, keep in mind that there must be continuity of each vent channel from intake to exhaust in order for moisture vapor that diffuses through the membrane to be carried away, and also for potential roof leaks. 24

27 Is the Sealed Attic System with Tyvek AtticWrap compatible with all types of roof coverings, including asphalt shingles, tiles, slates or metal? Yes. The Sealed Attic System can be used with any type of roof covering. Test data indicates that this system will not adversely affect the life of the roof. Does the Tyvek AtticWrap installation method comply with OSHA requirements? Installation of Tyvek AtticWrap TM with conventional harness and fall protection systems does comply with OSHA requirements. When installing Tyvek AtticWrap TM on a roof, all local OSHA requirements for working on roofs must be followed at all times. Can Tyvek AtticWrap be installed in a cathedral ceiling? Yes. A Sealed Attic System with DuPont TM Tyvek AtticWrap TM is an ideal addition to a cathedral ceiling assembly. Tyvek AtticWrap TM holds the insulation away from the vent channel and stops air leakage from inside the house at the same time. Always use the Rafter Cap or Furring installation methods for cathedralized ceilings. Will the installation of Tyvek AtticWrap affect my ability to finish off part of my attic for living space? The use of Tyvek AtticWrap TM will improve your ability to finish the attic and use it for living space. In addition, it will increase the attic s storage value. Tyvek AtticWrap TM keeps the attic drier and dust free, while moderating the extreme temperature differences experienced in a traditional vented attic. How does the Sealed Attic System with DuPont TM Tyvek AtticWrap help prevent water damage caused by ice damming? The Sealed Attic System helps reduce the heat loss through the attic and roof during winter. This keeps the roof surface cooler so ice dams aren t as likely to form in the first place. In the event an ice dam does form, Tyvek AtticWrap TM serves as a secondary weather barrier to collect and safely drain water that leaks through the roofing material. Is the Sealed Attic System a totally new concept? How many homes have been built with this system? The Sealed Attic System, pioneered by DuPont during the last decade, was introduced in Europe in Since then, hundreds of thousands of homes have been successfully protected with the Sealed Attic System in several countries in Europe. In the United States and Canada, DuPont has carried out an extensive field testing program which involved the construction and monitoring of 15 homes with the Sealed Attic System across different regions and different climates during the last three years. Which official third party accreditation bodies have been involved in the field testing of the Sealed Attic System? Part of the field testing program of the Sealed Attic System has been carried out under the supervision of Prof. Tang Lee from Calgary University, Joe Lstiburek of Building Science Corporation, Oak Ridge National Laboratory and the Florida Solar Energy Center. Should I expect my attic to be warmer during the summer and colder during the winter? No. Tyvek AtticWrap TM will keep the attic space temperature closer to the living space temperature than will a traditional vented attic. Tyvek AtticWrap TM will make your attic a semi-conditioned space, helping keep it cooler in the summer and warmer in the winter than a traditional open vented attic. 25

28 PRODUCT PROPERTIES Properties Method DuPont TM Tyvek AtticWrap TM weather resistive barrier Air Penetration Water Vapor Transmission Water Penetration Resistance Gurley Hill (TAPPI T-460) (sec/100cc) ASTM E-96 Method B (g/m 2-24 hrs) (US perms) AATCC-127 (cm) Breaking Strength ASTM D-882 MD/CD (lbs/in) 26/29 Tear Resistance (Elmendorf) ASTM-1922 MD/CD (grams) 4100/4800 Surface Burning ASTM E-84 Characteristics Flame Spread Indexed Smoke Developed Value 5 Class A 40 Class A Data listed above was measured by an accredited independent laboratory. Individual roll results may differ due to normal manufacturing variations. WARNING: DuPont TM Tyvek is combustible and should be protected from a flame and other high heat sources. If the temperature of DuPont TM Tyvek reaches 750 F (400 C), it will burn and the fire may spread and fall away from the point of ignition.

29 BUILDING CODE REPORTS Product has been submitted to ICC-ES with an Engineering Report as an alternate method. ICC-ES Evaluation Report is pending. TECHNICAL SPECIFICATIONS DuPont TM Tyvek used in construction products is made from 100% flash spun-bonded high density polyethylene fibers which have been bonded together by heat and pressure, without binders or fillers, into a tough, durable sheet structure. Additives have been incorporated into the polyethylene to provide ultraviolet light resistance. DuPont TM Tyvek AtticWrap TM has a thin aluminum coating on one side protected with a thin acrylic layer. DuPont suggests that Tyvek AtticWrap TM be covered within 4 months (120 days) of installation. PRODUCT REPLACEMENT DuPont will replace any Tyvek Weatherization System product damaged during installation by weather or normal handling if it is installed according to procedures published by DuPont. If you have any questions, call Dupont TM Tyvek Weatherization Systems at TYVEK. WARNING DuPont TM Tyvek is slippery and should not be used in any application where it will be walked on. In addition, because it is slippery, DuPont recommends using kickjacks or scaffolding for exterior work above the first floor. If ladders must be used, extra caution must be taken to use them safely by following the requirements set forth in ANSI Standards 14.1, 14.2 and 14.5 for ladders made of wood, aluminum, and fiberglass, respectively. Dupont TM Tyvek is combustible and should be protected from a flame and other high heat sources. Dupont TM Tyvek will melt at 275 F (135 C) and if the temperature of Dupont TM Tyvek reaches 750 F (400 C), it will burn and the fire may spread and fall away from the point of ignition. For more information, call TYVEK. NOTE To achieve greater potential, energy savings and weather resistance, any tears, breaks, holes, etc. created during normal construction should be repaired by taping or patching with DuPont TM Tyvek AtticWrap TM weather resistive barriers. DuPont TM Tyvek products are weather resistive barriers, not the primary water barrier (the outer facade is the primary barrier). Contamination of any DuPont TM Tyvek weather resistive barriers and building papers with building site chemicals which increase their wettability (e.g., surfactants) will adversely affect their water resistance and therefore, their contribution to the overall water resistance of the wall system. For superior protection against bulk water penetration DuPont suggests a system combining a quality exterior facade, a good secondary weather resistive membrane and an exterior sheathing, appropriate flashing materials and details; and high quality windows and doors with particular attention to proper installation of each component. In a system where no exterior sheathing is used and DuPont TM Tyvek is installed directly over the wall studs, exterior facade materials should be selected to ensure maximum protection against water intrusion. Careful workmanship and proper installation of each component is very important. DuPont believes this information to be reliable and accurate. The information may be subject to revision as additional experience and knowledge is gained. It is the user s responsibility to determine the proper construction materials needed. Because conditions are outside of our control, DUPONT MAKES NO WARRANTIES, EXPRESSED OR IMPLIED, AND ASSUMES NO LIABILITY WHATSOEVER AS TO THE PERFORMANCE OF THE PRODUCTS FOR A PARTICULAR USE. This information is not intended to be used by others for advertising, promotion or other publication for commercial purposes.

30 DuPont -Where Building Science and Technology Meet BUILT BY SCIENCE Backed by over 200 years of science, DuPont works closely with the world s leading architects, building engineers and designers to create products that help you build more beautiful, durable, energy-efficient and healthier homes and buildings. We introduce timeless materials that builders, contractors, dealers and homeowners depend on. DuPont remains at the forefront of building science, and we re committed to finding new ways to create homes and buildings that cost less to operate, are easier to maintain and provide more comfort for people around the world. It s all part of our commitment to real-world, innovative solutions that can help everyone live a better life. Strong Family of DuPont Products Whether you re building new, remodeling, or re-siding, DuPont has developed a family of weatherization systems products engineered to address all your building needs. DuPont weatherization systems products includes Tyvek HomeWrap, Tyvek CommercialWrap, Tyvek StuccoWrap, Tyvek DrainWrap TM, DuPont TM FlexWrap TM, DuPont TM StraightFlash TM, Tyvek Tape, Tyvek Fasteners, and our newest miracles of science, Tyvek AtticWrap TM and Tyvek ThermaWrap TM. The DuPont Tyvek Specialist Network There are over 160 professionals who have the tools, training and knowledge to help you build profits, quality and customer satisfaction. Every time you work with a DuPont TM Tyvek Specialist, you re working with someone who knows wall systems, R-values and construction best practices. In short, when you have a question about materials, techniques, codes or costs, your DuPont TM Tyvek Specialist will provide you with an answer. If your Specialist cannot answer you directly, he or she will find someone who can. For more information, Call us at: TYVEK Visit us at: Write us at: PO Box 80728, Wilmington, DE

31 THE SEALED ATTIC SYSTEM WITH DUPONT TM TYVEK ATTICWRAP TM PROVIDES A WEALTH OF BENEFITS Helps cut overall cooling and heating Channels moisture vapor Improves insulation performance Enhances roof ventilation air flow Regulates attic temperature Acts as a secondary weather barrier