How Many Layers Of Shingles Should Be On A Roof

Eliminating the tearoff can easily save 1 000 or more on a new roof but you re really just delaying the cost.

How many layers of shingles should be on a roof.

For example cedar or tile roofs are only allowed one layer. Most building codes allow up to two layers of organic or fiberglass asphalt shingles. On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing. A roofing contractors 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.

That limit pertains to roofs with up to a 4 12 pitch. For many years it was acceptable to put even the third layer. Roofing layers from the framing to the shingles. So we ll start at the bottom of the deck and work our way up through all the roofing layers until we reach the shingles and sunshine above your roof.

In the portland area as of 2018 the current code allows up to three layers if the current layer is in good condition. Underlays have remained intact after shingles have blown away thereby providing temporary roofing 7. For example there s a starter course of roofing shingles installed at the eaves before the roofing shingles you can see. 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.

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. Resins from green lumber roof decks have been known to interact with roof shingles and a separation layer of underlay can be useful. When it s time to replace the roof again and you have no choice but to start anew two layers is the maximum allowed in most areas you ll have to pay extra for the two layer tearoff and disposal. Asphalt shingles typically can have one more layer added over the top two roofs total.

However this depends upon the roof materials.