Aluminum Base & Cap System Installation Guide See - http://www.baseandcap.com Print large details specific to your installation. Minimum 1/12 (5º) roof slope required for polycarbonate. Install 8, 10, 16 or 25mm polycarbonate on structures with horizontal purlins set above rafters or trusses, arched roof structures or metal building frames. Base attaches to roof purlins & wall girts. Base may also be attached to vertical rafters & posts, proper blocking required for Load Support. - Cover a greenhouse, pool enclosure, large skylight or metal building frame. - Rafter & Post framing lets inner sheet condensation move past blocking. If condensation an issue on Purlin & Girt structure choose 16mm. 25mm best for high humidity pool enclosure. Easy-To-Install. Attach Base to purlins or rafters, lay on Polycarbonate & attach Cap. Leakproof. Aluminum Cap seals tight on polycarbonate. Cap Screws set quickly. Cap screws seal tight. Versatile. Specify Polycarbonate thickness & Cap Screw length will accommodate. Strong. Structure of aluminum Base profile will span over and attach to purlins, see load chart on p 3. Roof Access Notes for Install on Horizontal Purlin & Girt or Rafter & Stud Frame: Access to roof for Base, Cap, screw & flashing sealant done from step ladder positioned in empty roof bay to left or right of already installed poly. Install of 1st & last sheet done by placing ladder outside structure. Work from upper step so you can reach over sheet. 4 foot wide sheets are easier to reach over to set screws and are best for roof applications. Start at one end of the structure, work towards other end. Do all steps as you go and it will not be necessary to gain access to the roof again. Clean sheet with a hose. Do often. Access to the ridge to install and/or seal the flashing may also be achieved by placing 3 x 4 sheets of plywood, with Non-Slip Rug Padding glued to the back, over the installed polycarb. Select 3M #90 spray glue for best results. Advance planning to proceed as described in the previous paragraph may result in an easier installation. Your situation and skill level will dictate the best way to proceed. ( 1 )
General Install Note: Sheet must be supported on all 4 edges with a min. of 1/2" of sheet bearing on the Base or frame. When using sheets that are cut along the width, and no longer have a rib at the edge, position sheet so first rib is supported by a minimum of 1/2". For high winds see P 14. Position sheet so UV protected side faces sun and remove film from Both Sides of sheet prior to installation. Screw counting and attaching procedure for screws attached thru Corners, Polycarbonate that is adjacent to U-Profile and Flashing. For Horizontal Purlin & Girt or Rafter & Stud Framing: #10 x 2" wood or #12 x 1-1/2" self-drilling metal screws with 3/4" sealing washers are used when screwing through 8mm, 10mm & 16mm polycarbonate. #10 x 2-1/2" wood or #12 x 2" self-drilling metal screws with 3/4" sealing washers are used when attaching through 25mm polycarbonate. Roof Use 1 screw per foot along the top edge of roof slope. Set screw through ridge flashing and into purlin or blocking below. Use 1 screw per foot along the lower edge of sheet, positioned between Base & Cap. Aluminum Corner Trim (use 1 screw 2" from ends and every 12" along each leg of Corner). Walls Aluminum Corner Trim (use 1 screw 2" from ends and every 12" along each leg of Corner). On side or front walls, use 1 screw per foot along the top & bottom edge of sheet, position between Base & Cap. Screw goes through sheet and into girts or top & bottom plates. On gable ends, with Corner Trim at top of sheet, place 1 screw per foot along the bottom edge of sheet, position between Base & Cap. Screw goes through sheet and into girts or bottom plates. See above for screw placement in Corner Trim. Around Doors, Windows, Fans & Shutters 1 screw every 12" around perimeter as needed. Note: Base & Cap screws are provided. At order specify wood or metal frame. Screws to hold on U-Profile also provided. Base screws are attached to roof purlins and wall girts (or rafters & studs) as laid out in your design. Cap screws positioned 1-1-2" from ends and about every 12" on-center. Installation Tools & Supplies: - Marking Pen (medium point for laying out cuts on plastic film that covers polycarbonate) - Saw Horses & Planks (for laying sheet on when cutting) - Circular Saw and fine tooth plywood blade for cutting polycarbonate, or - Jig Saw with Fine Blade (option to using a circ. saw for polycarbonate, best for curved cuts) - Utility Knife & Sharp Blades (change often when cutting 8mm polycarb. for quick, safe cuts) - Fine Tooth Key Hole Saw (for cutting fan opening in sheet if jig saw not available) - Power Miter Box with fine tooth blade (for cutting extrusions) - Hacksaw (optional method of cutting extrusions) - Vacuum or Blower (for cleaning polycarbonate chips from center of sheet) - Straight Edge (for cutting polycarbonate when using a utility knife) - Spring Clamps w/rubber tips (for holding straight edge when cutting sheet) - Caulking Gun - Electric Dill for drilling holes in aluminum - Cordless Drill w/ adjusting chuck for driving screws to proper tightness or Socket Wrench - Magnetic Hex Head Drivers ¼ & 5/16 Plus 1/16", 3/16", 1/4" steel cutting drill bits. Standard twist type. - Satin Spar Varnish or Verithane: Coat surface poly. will rest against to protect wood. Prior to poly install apply foam tape. ( See P 15 ) Remember, bronze polycarb. moves a lot. ( 2 )
Method 1 - Install Over Roof Purlins or Wall Girts. Read before install. Recommended Purlin/Girt Spacing to Support Load, 48" wide Sheet, lbs. per sq. ft. Purlin/Girt Spacing 48 45 42 36 30 28 Bending Radius 8mm NA NA NA 20 lbs. 35 lbs. 40 lbs. 8 feet 10mm NA NA 20 lbs. 30 lbs. 60 lbs. 75 lbs. 8 feet 16 & 25mm 3-Wall 20 lbs. 25 lbs. 35 lbs. 70 lbs. 85 lbs. 95 lbs. 9 feet Purlin Spacing 90" 75" 63" 54" 48" 36" 16mm X-Wall NA NA 20 lbs. 35 lbs. 45 lbs. 80 lbs 120 25mm X-Wall 20 lbs. 35 lbs. 45 lbs. 60 lbs. 80 lbs. 105 lbs Do Not Bend Load in lbs./sq. ft. Roof slope over 7/12 snow tends to slide off. Spacing may be relaxed. No specs available A. Place 1st panel A (in some cases cut to size) on roof purlins or wall girts. Dimension from outside of structure to center of 1st or last Base is 48-1/2". Intermediate Base 48-3/4" to 49" oncenter. Then cover with Corner (see "B" above). B. Place Base C adjacent to panel & fasten with base screws to roof purlins or wall girts. Use two if purlin 2 wide or wider, for greater resistance against uplift, in extreme wind areas. Place 1 apart for maximum strength. Predrill holes in Base ¾ from end and every 12 on-center. (Select a standard point, twist type drill - 3/16 for Tan 1-5/8 Wood Screws & 1.25 Self Drillers, 3/16 for 1.5 Self Drillers, (used on metal frames). Leave about 1/8" between edge of sheet & vertical post in center of Base. Sheet should extend 1/2 past lower edge of roof Base, allowing for placement of U-Profile (drawings on following pages will show specifics for various details). At gable end, on the vertical ( 3 )
surface, extend Base to top of frame, Corner Trim covers top of sheet. surface, extend Base to top of frame, Corner Trim covers top of sheet. Aluminum tape covers sheet end under Corner, not U- Profile. A rib of the polycarbonate sheet must bear a minimum of 1/2" on Base for proper support. C. Place the next panel D in the open side of Base Extrusion. D. Fasten Cap E to Base (over the 2 panels) using #2 phillips bit in portable drill. Cap screws positioned 1-1-2" from ends & every 12" on-center (see p. 14 if over 90 mph wind). Predrill 3/16" hole in Cap as required. Set clutch for snug fit, using care to not strip screw head or threads. Position drill perpendicular to screw for proper alignment of screw. Continue with other sheets. E. Fasten Corner Trim and U-Profiles according to appropriate drawing/s presented in this manual. Also see notes on screw counting and attaching on page 2. Please note all Base & Cap and small screws to hold U at lower edge of roof included with your order. U-Profile is used at lower edge of roof sheets, top and bottom of side walls (freestanding structures) or front wall (attached structures), bottom of gable end walls and around doors, fans & shutters. Corner Trim used where roof meets gable end and on wall corners. Method #2 - Install Over Roof Rafter & Wall Studs. Read before install. Recommended Rafter/Stud Spacing to Support Load, 48" wide Sheet, lbs. per sq. ft. Blocking Placement Poly. Rafter/Stud Spacing 35 lb. load 45 lb. load 60 lb. load 80 lb. load 100 lb. load 8mm 48-3/4" to 49" every 2.5 ft. every 2.25 ft. every 2 ft. NA NA 10mm " every 3 ft. every 2.75 ft. every 2.25 ft. NA NA 16&25mm 3-wall " every 3.5 ft. every 3.25 ft. every 3 ft. every 2 ft. NA 16mm X-Wall " every 5 ft. every 4.5 ft. every 3.75 ft. every 2.75 ft. every 2 ft. 25mm X-Wall " every 6.25 ft. every 5.25 ft. every 4.5 ft. every 3.5 ft. every 3 ft. Load lbs./sq. ft. Roof slope over 7/12 snow tends to slide off. Spacing may be relaxed. No specs. Horizontal blocking (above) required for load support. In high humidity situations set 1/4" back from outer surface of frame, place spacer in middle of blocking and condensation will move past blocking. Or place vertical members between rafters or studs to support sheet. With intermediate vertical members horizontal blocking is minimized, vertical member supports mid-sheet load. 1/4" 2 x wood rafter Blocking and 3/8" x 1" Neoprene Spacer set 1/4" from top of framing, spacer in center of blocking. Use min. 2 x 2 wood or 1.5" x 1.5" metal tube 2" x steel or alum. rafter 48 3/4" to 49" for 48" polycarbonate sheet Only one Spacer in middle of sheet, at blocking 4 ft. sheet, two spaced even on 6 ft. sheet. (4)
A. Place 1st panel (in some cases cut to size) on roof rafters or wall studs. Dimension from outside of structure to center of 1st or last Base (rafter or stud) is 48-1/2". Then cover with Corner (see page 10). First and last Base position is less if polycarbonate sheet to overhang gable end. B. Place Base adjacent to panel (over roof rafters or wall stud) & fasten with base screws to roof rafter or wall stud. Predrill holes in Base ¾ from end and every 12 on-center. (Select a standard point, twist type drill - 3/16 for Tan 1-5/8 wood & 1.25 Self Drillers, 3/16 for 1.5 Self Drillers (for metal frames). Leave about 1/8" between edge of sheet & vertical post in center of Base. Sheet should extend 1/2 past lower edge of roof Base, allowing for placement of U- Profile (drawings on following pages will show specifics for various detail). At gable end extend Base to top of frame, Corner Trim covers top of sheet. Aluminum tape covers sheet end under Corner, not U-Profile. Note: A rib of polycarbonate sheet must bear a minimum of 1/2" on the Base for proper support. ( With vertical running rafters & studs Intermediate Base positioning is 48-3/4-49" on-center.) C. Place the next panel in the open side of Base Extrusion. D. Fasten Cap to Base (over the 2 panels) using #2 phillips bit in portable drill. Cap screws are positioned 1-1-2" from ends and about every 12" on-center. Predrill 3/16" hole in Cap as required. Set clutch for snug fit, using care to not strip screw head or threads. Position drill perpendicular to screw for proper alignment of screw. Continue with other sheets. E. Fasten Corner Trim and U-Profiles according to appropriate drawing/s presented in this manual. Also see notes on screw counting and attaching on page 2. Please note all Base & Cap and small screws to hold U at lower edge of roof are included with your order. U-Profile is used at lower edge of roof sheets, top and bottom of side walls (freestanding structures) or front wall (attached structures), bottom of gable end walls and around doors, fans & shutters. Corner Trim used where roof meets gable end and on wall corners. Note: Base & Cap screw positioning decreased in high wind area (see p. 14 if over 90 mph) General Install Note, for installing polycarbonate: Local building dept. can provide snow & wind loads for your areas The ability to support a specific snow load is a factor of frame strength and polycarbonate sheet rigidity. Wind load requirements are usually met by following standard screw placement guidelines as shown in the Installation Details. Cap receives screws at ends of each piece and every 1 ft. on center. When fastening Corner Trim or through polycarbonate (adjacent to U-Profile), screws with 3/4" sealing washers are to be set at corners of glazed areas and every 1 ft. on-center. For placement of screws in body of the sheet see Polycarbonate Positioning & Attachment (p 6). Difficulty getting the bldg. dept. to approve plans? Stress the frame is designed to support the load. Polycarbonate is a skin material only. If needed, suggest extra purlins or blocking to decrease unsupported panel size by 50%. Screw pattern can be increased for extreme high wind areas. See Structural Load on page 14. ( 5 )
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Ridge Flashing Install: Flashings are typically fabricated in 8 ft. sections. 1) Easiest method of install is to set and screw down a section of Flashing that covers first sheet of polycarb (on double slope roof - both sides). With Type A Flashing cut notches for Cap, page 8. On Type B Flashings the Caps butt to leading edge of the Flashing. Set screws so flashing presses against polycarb, place a bead of sealant at this point and stop there. Lay next sheet. Screw down Flashing & place bead of sealant along the edge of Flashing that comes in contact with poly, and also where Cap contacts Flashing. Continue installing more poly and Flashing. Overlap seams in Flashing min of 4". This method provides a watertight installation, but care must be taken to lay a smooth bead of sealant on a cleaned surface. 2) More difficult, but cleaner looking, tighter install involves installing flashing after all sheets set. See Lean-To Ridge and Freestanding Ridge details. This requires access to ridge with all poly in place. As mentioned Roof Access Notes, page 1, this can be tricky, best performed by individuals accustom to working on roofs. If working on an attached greenhouse you may be able to gain access to this detail from the roof of the adjoining structure. When installing A Type Flashing, first lay in place, mark where Flashing overlaps Cap at sheet seams. Notch to fit the Cap. When installed, Flashing will rest flat on the poly and Cap. Overlap seams a minimum of 4". On Type B simply butt Cap to sealing flange. Do not cut flashing to length, as this will create a slight curl at the cut & an uneven overlap. If the overlap ends up being 4 ft., ok. Purchase flashing from sheet metal fabricator, or off shelf at lumber yards. (If purchasing a metal building frame, you may get their ridge flashing). Do a simple scale drawing that shows dimensions, angle, etc. At edge of Type A Flashing that covers the polycarbonate we suggest a 1/2" long bend (flange). Draw so that the leg(s) of the flashing are tilted down 5 from the actual pitch of your roof. This will create a small amount of pressure against the polycarbonate sheet, useful in achieving a watertight installation. On Type B Flashing leading edge do a 1/2" hem and 45º bend, creating a sealant flange. Sheet metal should be a minimum of.019" aluminum or 30 gauge steel. Aluminum is easy to fasten through, easy to cut, but is a little flimsy and care is required in handling. Steel is more sturdy, harder to cut and requires pre drilling prior to fastening. Availability at your local sheet metal shop may be the limiting factor. Look in the Yellow Pages under Sheet Metal Work. Some shops, especially those that cater to glass installation contractors, inventory medium architectural bronze and anodized sheet metal in the thickness you will be looking for. These colors will be a close match to the Trim Components we offer. In high wind areas use Big Stretch, not silicone, to bond tip of Ridge Flashing to poly Sealant Selection & Application: Silicone used below eave, along Lean-To & Freestanding Ridge Flashing and interface between U-Profile and Existing Wall, see p 10. One may also close end of Cap, see p 14. See Install Details page online for more details and greater explanation. Use 100%, silicone. 1/4" bead best. First clean joints with rubbing alcohol and let dry. When splicing Cap or Corner place 1/4" bead of silicone over joint. Gently tool bead flat. Joints at interface of Trim Components should be clean & securely fastened. Make sure U-Profile is butted tightly so bugs do not get in. Allow sealant to dry 24 hrs. before cleaning the poly and metal. Dow 999-A Clear Silicone is recommended. Calculate running ft. of silicone required for project. One tube will do 25 feet of a 1/4 bead. In high wind areas use Big Stretch, not silicone, to bond tip of Ridge Flashing to poly. See Install Details page online for Big Stretch Product Data Sheet.
( 7 ) Ridge Flashing Notch Sealant Cap (at sheet seams) Type A Flashing: Screws with washers go through ridge flashing every 12 on-center. Drawing shows install on roof purlin. If using rafters a beveled ledger board is required. Type B Flashing: If using rafters drawing shows blocking. In high winds or expansion use Big Stretch.
( 8 ) Detail similar for purlin & girt or rafter & stud style framing. ( 9 )
Roof Corner and Wall Corner detail similar for purlin & girt or rafter & stud style framing. On purlin & girt style framing detail shows blocking laid between either purlin or girt. Lower Edge drawing shows install on wall girt or bottom plate, purlin & girt or rafter & stud style framing. U-Profile can also be used to close polycarbonate edges at top and end of walls. Gable install similar for purlin & girt or rafter & stud style framing. ( 10 )
Roof Valley & Poly. to Existing Roofing: Adhesive Roll Flashing (shown above & to the right) has 15 mil Butyl Adhesive (facing down) and a Aluminum backing (that faces the sun). For wider than 3" areas simply overlay, or use 6 wide tape. Make sure polycarbonate is securely fastened to the structure with the screws we sell. Surfaces must be clean and free of moisture and contamination. Do Not Stretch during application. Peel off a few inches of release liner. Apply exactly the first time and do not stretch. Press down firmly at the center and work towards the edge, removing bubbles. Edges must have no openings, tunnels or fishmouths. ( 11 )
Structural Loads & Special Screw Positioning for High Wind Areas. Structural Loads are stresses to structure from external or internal forces. Dead loads are gravity loads that are constant throughout the structure's life. These include equipment such as fans, heaters and plants suspended from the frame. Live loads are temporary, such as snow loads and wind loads. Snow loads are determined by factors influencing snow & ice accumulation on structure. Snow loads vary considerably by geographic location. Ask your local bldg. dept. for snow load in your area. ( 12 inches of light, fluffy snow or 2 to 4 inches of heavy, wet snow = about 5 lbs per sq. ft.) Wind loads come from any direction, usually hit side walls perpendicular, most stress at edges. Figures are in lbs. per sq. ft Wind 85 mph 90 mph 100 mph 120 mph 130 mph 140 mph 150 mph 160 mph 18 20 25 36 43 48 56 85 Above wind load figures provided by SABIC Innovative Plastics, the Lexan manufacturer. Wind speeds up to 90 mph: Screws with 3/4" sealing washers are set at corners of glazed areas and every 1 ft. on-center. Base & Cap System : Screws provided with system to attach Base to frame and Cap to Base. The Base, Cap and Corner receive screws at ends of each Trim piece and every 1 ft. on center. In winds of 110 mph+ decrease distance between screws to every 10". In winds of 125 mph+ place screws every 8 inches. In winds 135 to 150 mph place screws every 6 inches. In winds over 110 mph always consult with engineer to receive a stamp and bldg. dept. approval. For placement of screws in body sheet see Polycarb. Position & Attach, page 6. Increase quantity of screws in mid sheet, horizontally across sheet, to every 12" for wind speeds 110-130 mph. 10" for wind speeds 131-150 mph. Combination loads are common. For example, a snowstorm may include high winds. If bldg. dept. says design for a 45 lb. snow load & a 90 mph wind, snow will effect the roof with a 45 lb. load and wind will effect roof as well. To safely design your roof framing, take the 45 lb. snow load, and add for positive loading effect the wind may have on the roof. Your bldg. dept. can provide the combine load. ( 12 )
The expansion and contraction of poly can create noise, follow instructions below. Foam tape gets applied as shown for Base & Cap System. In Base there is a 1/2" channel to put tape in. Use care to not overlap 1/4" shelf to right and left of channel. - Tape not required on low friction surfaces, such as uncoated wood, aluminum or steel. - If spacer used, to set back blocking, then no foam tape required at blocking. Note: Sufficient quantity of foam tape provided, at no cost, with your Base & Cap order. Note: PVC will outgas and attack the poly. Only use our tape. ( 13 )
Notes: To seal ends of Cap fill with silicone. Not crucial in vertical applications, unless subject to direct rain. We highly recommend Dow 999 Plastic Compatible Silicone ( 14 )
Install Policy - Crucial for Seasoned Builders Manufacturer goes to great lengths to provide complete install guidelines for the Base & Cap System. Often installers do not follow install instructions and problems occur such as leakage, noise, excessive flexing of the sheet, etc. By placing an order customer agrees to installation policy. In doing so customer agrees to follow install guidelines and details or be fully responsible for adverse consequences due to not following instructions. If problems occur with materials at time of install Contact Distributor Immediately. Proceeding with your own solution could easily create more problems and may actually void polycarbonate warranty. Always avoid direct contact with PVC films or tapes. Blocking & Purlins: These terms can have different meanings in different areas of the country and in different trades. To ensure successful framing and installation of polycarbonate, using the Base & Cap System, it is crucial that we agree upon One Definition. Below is how our details and printed material uses these terms. Blocking is a small (horizontally running) framing member that is positioned "Between" rafters or studs, and is on the same plane. Purlins are long (horizontally running) framing members that are "Placed on the Outer Surface" of rafters, trusses, posts or other main frame elements. The Base extrusion has sufficient strength to carry the loads when placed above and attached to purlins or girts, acting as a structural support member, supporting the polycarbonate at sheet joining locations. Always refer to load charts for proper spacing of purlins. Girts are simply purlin like items that are on the walls. Purlins are technically on the roof. Terminology in General: Kindly refer to product information and use our terminology in conversation with distributor and in your plans. Very Expensive mistakes have been made by customers using terms that are appropriate for other products and in other trades, or terms that are common in certain regions, but are not the terminology we use. We use standard architectural terminology and terms specific to our products. For this design and construction process we request your gracious compliance to our terminology. Often people call the U-Profiles - Caps instead. They are thinking the U-Profile shape but order Caps. Given that returned aluminum always arrives damaged, we do not accept returns. A costly mistake that can easily be avoided. (15)
Base & Cap System - Screw Usage General Guidelines: Avoid leaks, failures and expensive call backs. - It is extremely important to use proper screw in the proper location. - Always pre-drill holes in Base, Cap & Corner for screw placement. Self-drilling screws are Never meant to drill thru these components. - Self drill screws pass thru components, fastening both to the frame. - Screws with 3/4 washers are only meant to go thru the edges and body of the polycarbonate sheet and Corner Trim. - Golden Rule: Do not assume you know where screws go. Refer to install drawing specific to the detail you are addressing and see descriptions below. Failure to do so may result in improper installations and possibly void warranty. Screws in Bags with Labels - Please follow instructions #6-3/8 Self Drill Screws - Phillips Drive - Pan Head - For U-Profiles - LABEL: 3/8 S Steel Screws to Secure U-Profile to Sheet as Job Requires #10 Self Tapping Screws - Phillips/Square Drive - Pan Head - For Cap - LABEL: Screws for Securing Cap Extrusion Base & Cap System #10 x 1-5/8 Wood Screws with a Phillips/Square Head - For Base - LABEL: Screws for Securing Base Extrusion Wood Frame #10 x 1.25 Self Drilling Screws with a Hex Head - For Base - LABEL: Screws for Securing Base Extrusion Metal Frame (8 &10mm) #10 x 1.5 Self Drilling Screws with a Hex Head - For Base - LABEL: Screws for Securing Base Extrusion Metal Frame (16 &25mm) Bags of Painted Screws with Assembled Washers & Bags of Unpainted Screws & Washers for Pressure Treated & Metal Frames - These Only go thru top and bottom of Poly Sheet, along outside edges of first and last Poly Sheet, and thru both surfaces of Corner Trim (typically every 1 ft. on-center) and in Body of Poly as noted on page 6 of Base & Cap Install Guide. Please note, in areas with winds over 90 mph the screw spacing must be decreased see page 14. (16)