For decades roofers have fitted a layer of felt over a roof s sheathing or roof deck before installing shingles.
Single layer roofing felt.
This can include epdm rubber and fibreglass pvc tpo tpe and pib.
Sometimes called roofing felt underlayment roofing tar paper or roll roofing this is a layer of protection installed between the roof deck and the roofing shingles.
Single layer bitumen roofing membranes deliver high performing lightweight flexible roofing systems which are also easier safer and quicker to install.
That s because on roofs like the one in the photo with slope of 4 12 or greater only a single layer of felt is required under asphalt shingles.
Single ply roofing cost.
One layer is bonded to the deck and then another one or two laid on that.
Vertical joints should lap a minimum of 4 inches and be offset by at least 6 feet in successive rows see figure 2 2 at left.
In a single coverage felt installation the lower edge of each course overlaps the previous course by a minimum of 2.
Firstly these membranes generally share some desirable traits.
Felt done properly should last more than 10 and up to 25 years in the right place.
Most shingle warranties do not apply when shingles are layered over existing roofing according to internachi.
The cost associated with the material and installation can vary widely depending on roof conditions the attachment used and the type of membrane being installed.
Roofing felt offers an additional layer of protection against the elements.
What is a single ply membrane.
In short any roof covering that can make a flat roof waterproof in one layer unlike roofing felt with its 3 layer system for instance.
Asphalt saturated felt starting at the eaves and lapping upper courses over lower by a minimum of 2 inches.
You can t fit a dpm on the deck first and there is no advantage in it in any case.
Some roofers install a layer of waterproof shingle underlayment wsu over the existing shingles at the eave end as would be done for a roof laid on bare sheathing.
Why roof shingles work best in single layers the temporary savings you receive from adding a second layer of shingles does not outweigh the negative aspects.
Click to enlarge any image.
Single ply roofing is priced per square foot and an average price for materials and installation of a 60 mil roof may range from 3 to 5 per square foot.
Single layer roofing membranes.
This provides added protection against ice dams.
On roofs with a slope of 4 12 or greater use a single layer of 15 lb.
