Second Layer Of Roof Shingles

I don t know if a precise formula like that exists but the second layer does have less firm foundation than the first and it would be logical to expect shorter life span.

Second layer of roof shingles.

Make repairs before. In fact the extra layer can reduce your roof s lifespan by up to 40. I won t speak to a haphazardly done job. How to put on a second layer of shingles evaluate the job.

I think you ve got a good life out of it. It is common practice to add a second layer of shingles over an existing single layer provided the roof decking is intact and the roof surface is flat. However there are good reasons it doesn t really cut down much on the amount of work. But check the shingle warranty from your shingle manufacturer.

Still you ve got no less than 17 years from it already. Another issue is that when you add in the second layer it can add extra weight to your roof. That can be either architectural shingles or conventional 3 tab shingles. And so second layers generally don t last as long as the first layers.

It forces more oil to evaporate out of it and more of the materials that make it pliable and watertight. The second layer of shingles will trap heat which can result in the decomposition of both roof layers. Before you add shingles over shingles you need to look at the existing roof to make sure. This will force you to replace your roof earlier than expected.

And shingles have started to separate. You will get what you pay. Examine the existing 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.

How to shingle over existing shingles and how to shingle a roof how to install roof shingles shingle layout lines h. That second layer of shingles won t last as long. Before you start hefting shingles to the roof consider whether or not the project is worth doing.