2 Layers Roof Shingles

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

2 layers roof shingles. Asphalt shingles typically can have one more layer added over the top two roofs total. 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. Another issue is that when you add in the second layer it can add extra weight to your roof.

The second layer of shingles will trap heat which can result in the decomposition of both roof layers. Two layers of shingles trap more heat which in turn damages the shingles and shortens the life span of the roof. In fact the extra layer can reduce your roof s lifespan by up to 40. On most flat roofs such as epdm tpo or modified it is perfectly acceptable to two layers of roofing.

This will force you to replace your roof earlier than expected. Roofers will have to work harder and longer to remove two layers of shingles later making the savings only temporary. If your decking is less than 3 4 inch then a 1 1 2 inch nail will suffice. 3 tabs are less expensive but also less durable have lower wind resistance and have a flatter appearance.

Two layers is the maximum in most areas but some building codes allow only one. Here is a video on how we lay a second layer of asphalt shingles over existing asphalt shingles. Saving on the initial shingle installation doesn t solve the long term cost of adding a second layer of shingles. 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.

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. For many years it was acceptable to put even the third layer. 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. 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.

Hope you like it. 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.