How Many Layers Of Roofing Are Allowed In Oregon

For example cedar or tile roofs are only allowed one layer.

How many layers of roofing are allowed in oregon.

Most building codes allow a structure to have two roof membranes. That limit pertains to roofs with up to a 4 12 pitch. In the portland area as of 2018 the current code allows up to three layers if the current layer is in good condition. Homeowners have to also keep in mind that most roofing materials are heavy and can easily weigh over a ton.

Most building codes allow up to two layers of organic or fiberglass asphalt shingles. For many years it was acceptable to put even the third layer. However this depends upon the roof materials. 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.

On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing. Item 3 in section r907 3 requires old roofing to be removed when there are two or more layers of roof covering. The previous code allowed up to three layers of roofing before removal was required. Your three layer roof is definitely a potential structural concern and homeowners insurance companies might consider three layers of roof shingles.

Adding a second or third layer of shingles adds significant weight to the structure. One of these major factors is cost savings. To get straight to the point there should be only 2 layers of roofing materials on your roof. The soundness of the building you re re roofing is another consideration.

October 3 2019 west valley city how many layers of roofing are allowed reroofing roof layer roof replacement roofing service contractor by admin although roofs are meant to last decades there will come a time that they will deteriorate and need to be replaced. 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. However in almost all areas it is not acceptable to install more than two layers of roofing on any commercial building. But contractors who spoke with angie s list say best practices call for stripping the roof down to the wood deck to inspect it before installing a new roof.

Effective april 1 2003 the ability to re roof over two layers of existing roofing is no longer allowed.