How Many Layers Roof Has Shingles

Architectural shingles make up most roof replacements today as their cost is only marginally more than 3 tab and they come with far superior specifications and.

How many layers roof has shingles.

For example there s a starter course of roofing shingles installed at the eaves before the roofing shingles you can see. Good quality composite shingles can weigh 350 to 450 pounds per square 100 square feet of roofing installed. Most cities and towns allow a maximum of two layers of shingles says chad muth president of muth company roofing in westerville ohio. On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing.

There are multiple layers of materials and they have to be installed in the right sequence and the right way in order to withstand harsh weather and keep your home dry. Asphalt shingles come in two major types 3 tab and architectural. 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. Most building codes allow up to two layers of organic or fiberglass asphalt shingles.

Your three layer roof is definitely a potential structural concern and homeowners insurance companies might consider three layers of roof shingles. Roofing layers from the framing to the shingles. 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. 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.

For many years it was acceptable to put even the third layer. 3 tabs are less expensive but also less durable have lower wind resistance and have a flatter appearance. For example cedar or tile roofs are only allowed one layer. 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.

However this depends upon the roof materials. In the portland area as of 2018 the current code allows up to three layers if the current layer is in good condition. 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.