ROOF ASSEMBLY FURNACE VENT In the utility room or where the furnace is located, there is an access panel to inspect the furnace chimney pipe for gas fired units. Remove the cover and check to see that the chimney is not dislodged and that it is correctly installed. The chimney pipe is a dual intake and exhaust unit. The cap unit generally must be installed when the home is assembled. Usually 3 screws are used to attach the vent top to the pipe. Any damaged or missing parts must be repaired or replaced. Be sure the opening is sealed against leaking until it is finished. WATER HEATER VENT The water heater chimney for gas fired water heaters must be checked to ensure that it is correctly installed and has not been dislodged in transit. Often the water heater exhaust pipe cap is damaged during transportation. It must be repaired or replaced if it is damaged or missing. Be sure the opening is sealed against leaking until it is finished.
FIREPLACE CHIMNEY If the home is provided with a wood burning fireplace, there will be a ship loose chimney top to install during installation. Follow the included manufacturer s instructions and assemble the sections as appropriate. Generally the sections snap together. There is a spark arrestor top installed with sheet metal screws and a flashing and collar at the base. Any missing or damaged parts must be repaired or replaced. The roof must be protected against leaking until the chimney is finished. The chimney must extend at least 2 above any part of the roof within 10 of it. A fireplace must have an intake combustion air duct installed to plan. Here is a skylight dome. Be sure that it is complete, clean inside and secure properly. Replace any missing or damaged parts and protect the opening from leaking before it is finished. Roof hold down strips stapled on at the factory must be removed. The staples or nails must be removed and the holes sealed with an all weather sealant. If practical, lift the outer tab and inject sealant into the fastener hole, then allowing a dab to spill over, set the outer shingle tab back onto it. ROOF UNDERLAYMENT On a typical two section roof, the roof cap must be completed on site. Before capping the roof, you must ensure that any roof deck access panels are fastened down to plan along the roof ridge line. Next, ensure that shingles prohibiting the proper installation of roof underlayment are removed. Patch all torn underlayment with roof sealant and underlayment paper. Be sure the underlayment and patch material are always installed in a shingle type manner having the upper side tucked under the upper course and the lower
side overlaying the lower course. The connections should have adequate overlap and a bead of roof sealant at the joints can be used. Here is a roof with strips of decking removable to access the roof bolts. This decking must be fastened to plan to prevent being blown off. The underlayment is usually in very bad condition where it meets the access panels. Take the shingles back as far as necessary to properly overlay the roof underlayment. The underlayment is the last line of defense for moisture protection, especially from water driven under the shingles in high winds. Roof underlayment is often accomplished using a single ply fiber reinforced product such as Ply Dry. The factory rolls out a complete sheet and glues it down over the lower Ice dam and eave drip metal and then applies drip metal over it at the rake ends. ROOF CAP
The underlayment is incorrectly installed over shingles. The glue strips are not ineffective and wind driven rain can be blown under the paper and into the roof where it can end up damaging even sidewalls. Always take up rows of shingles until the underlayment can be installed over the lower course underlayment. If there are not enough shingles, get more. STAND UP ROOF Before attempting to assemble a stand up or truss on site roof, have a full tarp and hold downs available and ready to protect the home. Cover the roof every day until it is completed The roof is stood up with special jacks or a crew of workers, the strut legs are dropped into place and fastened to plan.
When a gap exists between roof sections to be married, the gap should be shimmed as tightly as practical. When properly shimmed, a crush fit is created which will prevent movement between the sections.
The strand up roof sections have hinged drop down struts that get screwed to a runner board and shimmed as necessary to bear fully. A whole house fan vent pipe is connected to a vent cap at the roof. This is a view down the ridge line where the mating ridge boards meet and the hinged struts are fastened into place.
Sky light tubes must be installed to plan. After standing the rafters up and fastening struts, ridge boards and lagging the units at the lower ridge beams, the decking must be installed and the vents cut in if needed. This roof has a Dutch hip gable end. Out looker supports must be installed to plan to support the soffits and facias.
As roofing proceeds, cut out at vent openings and apply a bead of roof sealant at the opening as depicted. Apply a bead of sealer to the roof vent and fasten it over the vent opening. Once the vent is fastened down, apply sealant over the edges and fasteners.
Finish roofing following the roofing manufacturers instructions. Fully strip any damage roofing or roofing that must be taken back for repairs, underlayment and shingle tie in. Note the cut shingle valley is cut on the wrong side. The correct installation requires the cut to be on the side with the greatest water shed which would be the left side of this valley, not the right. While it is not likely to leak, a greater amount of water shed will work against the cut.
This cut valley is correctly placed on the side with the greater roof shed. SITE INSTALLED TRUSS ROOF ROOF VENTS AND FLASHING DETAILS Site installed dormers are sometimes included in the ship loose materials. They take a good deal of time to assemble, deck, roof, install eaves, soffits and facias. The finished roof may have a great many vents to install unless it has been modernized with soffit and gable vents or soffit and ridge vent.
It is important to leave access to the attic space for an inspection of the framing and venting, chimneys and flue pipes. The vent on the left has shingles run right up to the vent, allowing water to be trapped and possible back up instead of draining around the vent. The vent on the right is properly shingled to allow drainage. Do not use asphalt based sealant with the vinyl roof vent.
Here is improper roof underlayment installation. The paper should extend to the end of the metal drip edge on the eave side and be under the drip edge on the rake side. This drawing shows the proper installation of underlayment, drip metal and starter shingles. The roof underlayment patched in at the roof closure is incorrectly placed over the gable end drip metal. The paper should be placed and then the drip metal installed over it.
Here is an overexposed shingle. Today almost all the shingles used are metric sized and allow a maximum exposure of 5 5/8. Note the upper single starts beyond the top of the keyway in this case. Here s a sewer vent pipe and flashing before correct installation. Sewer venting is generally accomplished by venting through the roof with a 2 ABS pipe run through a flashing with a sealed rubber or flashing gasket around the pipe. The vent pipe must extend 6 through the roofing and the pipe must be painted to protect it against sun damage. This vent is cut off too low. It must extend 6 above the roof deck to be effective. The drain piping may not flow correctly as a result. This item should be deferred to the factory for service or repaired.
The home had strips of panel stapled to the roofing at the hitch end that must be sealed. Lift the shingle tab and inject roofing cement into the hole, leaving a dab extra to seal the hole in the outer layer. This roof decking is not aligned properly. Though the floor aligned correctly, the roof decking was about ½ higher where the C section met the B section. As a result of the uneven decking, the roof paper was cut at the edge and water was blown under the shingles and pooled at this uneven decking. The damaged sheetrock took more time to repair than the roof. The roofing had to be taken up, the decking shimmed even and reinstalled. Here is an exposed roof nail. This is not likely to leak, however, it should be placed so it does not occur at or near a keyway. Follow the shingle manufacturer s recommendations for fastening the shingles. It can be found on their shingle packaging. When properly placed, roof fasteners will not appear in shingle keyways.
When a chimney chase or other feature with siding and trim is installed above the roofing, there should be 2 clearance from the siding to the roofing to prevent deterioration. Do not under any circumstances hire incompetents to work on a home installation. Their incredible incompetence may cost an entire home as is the case here. The mold damage on this one year old home is so bad it had to be replaced. Notice the roof gap is not shimmed, there is no underlayment, the upper course shingles are overexposed at least 2 and of course wind damage results. A slight wind will blow rain under the shingles and soak the home The installer did not even try to use the factory provided marriage line underlayment in the ship loose materials. This case of low bidder savings cost a couple hundred thousand.