Can you put two layers of shingles on a roof?

Most building codes allow up to two layers of organic or fiberglass asphalt shingles. That limit pertains to roofs with up to a 4:12 pitch. … Think of it this way: By leaving the existing layer of shingles on your roof, you’ll save on both labor costs and disposal costs.

Is it bad to have 2 layers of shingles?

Two layers of shingles trap more heat, which in turn damages the shingles and shortens the life span of the roof. … Adding a second layer could compromise the structure of your roof. Problems fixing leaks: A second layer of shingles only complicates the job when a roofer is trying to fix a leak.

How many layers of roof shingles are allowed?

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. 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.

Is it OK to put shingles on top of shingles?

You might be able to lay new shingles over existing shingles and avoid the cost of tear-off. If conditions are right, new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing. … But you must take care to install shingles correctly so they lie flat.

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How long does a reroof last?

The 26 gauge and 29 gauge cheaper metal roofing options can last for up to 25 years if taken care of. On the high-end, the 24 gauge metal roofing option can last for up to 50 years. However, most manufacturers offer a 20-year warranty and some even a lifetime warranty which is dependent on the metal used.

Can you double felt a roof?

So it is possible to have 2 layers of felt in General. For instance, an alternative to 30# felt is to put two layers of 15# felt, or often 2 layers are recommended on a 2/12 pitch roof. In the “good Old Days” it was often doubled up to help resist ice dams (now delt with by Ice and water Shield).

Can you put a roof over an existing roof?

Roofing over an existing roof is also called reroofing or an overlay. It is the process where roofers install a new roof over your existing one, i.e. add a new layer of shingles, which means that there is no tearing off of the old roof.

Do I need to tear off old shingles?

In most cases, more than two layers of roofing shingles does require a tear-off. Laying new shingles over old shingles is easily prone to leaks and reduces the life of the new shingles. This alone ought to be reason enough to do a tear-off; it’s just a bad value not to.

Can you repair a 2 layer roof?

If you already have two layers shingles, the decision is made for you. The International Residential Code says that you cannot put a new roof over two or more applications of any type of roof covering. Part of the reason has to do with weight and its effect on the structure of your home.

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Can I put 3 layers of shingles on my roof?

House roofs should never exceed three layers of shingles. Adding additional layers without excavation can save homeowners up to $1,000 in labor. Therefore, layering has advantages. … High quality asphalt shingles are the best roofs to install multiple layers on.