Homeowners considering asphalt shingle installation over unvented attics should consult asphalt shingle manufacturers to verify warranty coverage spray foam insulation is more expensive than batt insulation and needs to be expertly installed to prevent missed areas or pockets that can reduce the efficacy of the building envelope.
Shingle warranty unvented roof.
All stainguard labeled shingles and ridge cap shingles carry a 10 year limited warranty and 1 year non prorated period.
Please refer to the warranty table for the shingle you are considering.
But foam that isn t installed according to building code requirements and manufacturer s instructions can lead to condensation problems mold growth and roof deck deterioration.
Unfortunately homeowners sometimes see the term of their warranty and assume that s how long their roof will last.
As the osb or plywood roof sheathing absorbs moisture the sheathing expands and decreases the space between adjacent sheets.
Gaf elk s shingle warranty is still valid when the shingles are installed over a roof deck insulated with spf foam which can be an effective method of boosting a home s energy performance.
A bill woodring director of technical services at gaf materials corp responds.
I ve read that a 3 4 vent space doesn t dissipate heat fast enough to really make much of a difference.
All stainguard plus labeled shingles carry a 25 year limited warranty and 10 year non prorated period against algae discoloration caused by blue green algae also known as cyanobacteria.
Lighter shingles are better than darker shingles.
My understanding is that shingle manufacturer s won t warranty their shingles in such applications except for elk which did but i guess no longer does.
A warranty that covers replacement shingles but not labor may be worth only a few hundred dollars of the thousands needed to repair or replace your roof.
The specific length of the tru protection period varies by type of warranty and shingle installed.
But what about asphalt shingles on such unvented roofs.
Speedbumps in the warranty process although your shingles may be covered by a 30 or 40 year warranty most of these long term warranties are prorated after the first few years.
This phenomenon occurs regardless of whether the roof is vented or unvented in the absence of a vapor barrier between the asphalt shingles and the roof deck.
Often the corners start to curl up after 6 8 years or so and the aggregate wears thin.
There does seem to be a greater chance of early shingle failure on unvented roofs than on vented roofs based on my personal observations of our own projects over the years in the boston area.
Each warranty starts with a tru protection period during the initial years where coverage includes labor cost to repair replace defective materials.