How Many Layers Of Roof Shingles Are Allowed In Nj

Steep sloped roof products such as tile slate metal and shakes only allow one layer.

How many layers of roof shingles are allowed in nj.

Three slate roof the new jersey home inspection includes a visible inspection of the exposed roof areas of the roof. New jersey call 908 757 3400. That limit pertains to roofs with up to a 4 12 pitch. 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.

For many years it was acceptable to put even the third layer. It is not illegal. Standard roofing practices allow for three layers of roofing shingles. 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.

Asphalt shingles typically can have one more layer added over the top two roofs total. However this depends upon the roof materials. Most areas only allow for a maximum of two layers. This will also be constrained by other factors.

In some instances 3 layers may be allowed but this is rare. Most building codes allow up to two layers of organic or fiberglass asphalt shingles. In the portland area as of 2018 the current code allows up to three layers if the current layer is in good condition. For roof slopes of four units vertical in 12 units horizontal 4 12 or greater underlayment shall be a minimum of one layer of underlayment felt applied shingle fashion parallel to and starting from the eaves and lapped 2 inches.

If the third layer is new you should not have to do. On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing. For example cedar or tile roofs are only allowed one layer. 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.

A roofing contractor will know exactly how many layers of roof shingles are allowed in your area for your building but it is normal that you will be permitted up to three layers of shingles.