Most building codes allow up to two layers of organic or fiberglass asphalt shingles.
How many layers of roofing are allowed in nyc.
Any amount of short term savings you might see from a layover roof installation is not far outweighed by the longer term peace of mind that comes from knowing that the integrity of the decking has been confirmed.
The homeowner will have two layers of shingles protecting the roof and the home is less likely to have ice dams he says.
However this depends upon the roof materials.
Why would you want to recover vs tear off.
That limit pertains to roofs with up to a 4 12 pitch.
Richards also estimates that the homeowner saves at least 1 000 in costs associated with removing and properly disposing of the existing shingles.
Local codes might not allow re roofing.
If the structure can support the added weight a typical 20 square 2 000 square foot reroof will cost at least 1 000 less than a tear off job.
For many years it was acceptable to put even the third layer.
Two layers is the maximum in most areas but some building codes allow only one.
Although the new york state building code does allow for up to two layers of roof materials.
Disadvantages to a roof recover.
Homeowners have to also keep in mind that most roofing materials are heavy and can easily weigh over a ton.
Your three layer roof is definitely a potential structural concern and homeowners insurance companies might consider three layers of roof shingles.
When it s time to replace your roof there are several factors that might lead your roofing professional to recommend adding shingles on top of your existing layers.
On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing.
How many should there be.
The soundness of the building you re re roofing is another consideration.
For example cedar or tile roofs are only allowed one layer.
Most building codes allow two layers of organic or fiberglass asphalt shingles on roofs with a 4 12 pitch or less and three layers on steeper roofs.
In the portland area as of 2018 the current code allows up to three layers if the current layer is in good condition.
Generally it is fine to have three layers of shingle but you should check this with your local building permit people and you should make sure that your roof and the rest of the structure have the strength to cope with the extra weight.
