2 Layers Roof Shingles

If you are putting a layer of asphalt shingles over an existing layer of asphalt shingles on to a 3 4 inch deck or a plank deck then you should be using 1 1 2 inch nails.

2 layers roof shingles.

Asphalt shingles come in two major types 3 tab and architectural. For example towns in climates with heavy hailstorm activity or significant ice dam problems may not allow multiple roofing layers. This is especially true if you ve overlayed your new shingles on top of warped shingles. If the structure can support the added weight a typical 20 square 2 000 square foot reroof will cost at least 1 000 less than a tear off job.

In fact the extra layer can reduce your roof s lifespan by up to 40. 3 tabs are less expensive but also less durable have lower wind resistance and have a flatter appearance. For many years it was acceptable to put even the third layer. Roofers will have to work harder and longer to remove two layers of shingles later making the savings only temporary.

Most building codes allow two layers of organic or fiberglass asphalt shingles on roofs with a 4 12 pitch or less and three layers on steeper roofs. Here is a video on how we lay a second layer of asphalt shingles over existing asphalt shingles. If your decking is less than 3 4 inch then a 1 1 2 inch nail will suffice. On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing.

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. Asphalt shingles typically can have one more layer added over the top two roofs total. The second layer of shingles will trap heat which can result in the decomposition of both roof layers. Shingles are the element that most homeowners are familiar with as it is the layer you can see from the outside of your home and it is an important aesthetic aspect.

Hope you like it. Most cities and towns allow a maximum of two layers of shingles says chad muth president of muth company roofing in westerville ohio. Two layers is the maximum in most areas but some building codes allow only one. Another issue is that when you add in the second layer it can add extra weight to your roof.

Having multiple layers of shingles is going to make your roof hotter because the heat gets trapped between the layers which could mean premature aging of the shingles. Two layers of shingles trap more heat which in turn damages the shingles and shortens the life span of the roof.