2 Layer Shingle Roof

Because the first layer holds a lot of heat and that can over the long haul wear out the second layer because that heat is the enemy of the asphalt shingle.

2 layer shingle roof.

This is the starter row shingle. That second layer of shingles won t last as long. 4 layer shingle roof tear off duration. Building codes and most municipalities will usually allow you to overlay a second though never a third layer of asphalt shingles over an existing shingled roof.

Doing a second layer right means a lot of prep work goes into the overlay anyway and flashing which remember is the most vulnerable point on your roof is harder to guarantee. So chances are if your roof already has more than one layer of roofing you re ineligible. This will force you to replace your roof earlier than expected. The second layer of shingles will trap heat which can result in the decomposition of both roof layers.

That in itself eats away at the savings. Walter wilson 3 831 views 3 23 diy shingles over existing roof duration. Another issue is that when you add in the second layer it can add extra weight to your roof. You are correct that second layers typically don t last as long as single layers.

Never do a shingle over. It isn t uncommon to layer a second roof right over the first and then tear everything off before you put a third layer down. In fact the extra layer can reduce your roof s lifespan by up to 40. The savings you re going to see may be in the range of a modest 25.

The resulting shingle will be 1 2 the height and the same length as an uncut shingle. Cut enough shingles to cover the length of the lower edge of all roof planes. However i ve seen older homes that experience severe settling after a second roof is added over the first. 2 layer reroof tear off.

If you only have a single layer of roofing currently and your home is fairly new structurally the home will probably withstand the extra weight. If you put a second layer on the second layer doesn t usually last as long as the first layer. Having an old layer of roof shingles under your new layer accelerates that process as the original layer holds a lot of heat. Collizaki 90 995 views 9 39 applying asphalt roof shingles bob.

Apply the starter shingle so that the.