Most building codes allow up to two layers of organic or fiberglass asphalt shingles.
How many layers of shingles are allowed on a roof in kentucky.
Generally it is fine to have three layers of shingle codes but you should check this is the case 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.
The soundness of the building you re re roofing is another consideration.
The contractor may do a walk on the roof and also inspect from the attic for any rot before installing a second layer of shingles.
Most areas only allow for a maximum of two layers.
For example cedar or tile roofs are only allowed one layer.
According to the international existing building code homes can be re roofed one time by applying a second layer of roof shingles over the existing one but after that application begins to wear both layers need to be removed before a brand new roof is installed.
The average 30 square roof uses 90 bundles of shingles and a bundle of asphalt roofing shingles weighs about 100 pounds which means you re putting roughly 9 000 additional pounds of weight on your roof.
There are important reasons why this code is in effect.
In the portland area as of 2018 the current code allows up to three layers if the current layer is in good condition.
Regulations allow a maximum of two layers of shingles on a roof but experts say you shouldn t lay asphalt shingles over an existing roof.
The old shingles become a layer that can foster mildew growth and trap layers of moisture.
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.
It s also worth remembering that simply reroofing over your old shingles may lead to a less durable roof.
However this depends upon the roof materials.
New roof covering materials are generally allowed to cover only one layer of existing roofing material.
So how many layers of roof shingles are allowed.
That limit pertains to roofs with up to a 4 12 pitch.
Adding a second or third layer of shingles adds significant weight to the structure.
Finally consider whether reroofing over the.
Some home insurance policies will not cover roof repairs that include multiple layers of shingles.