Problems with Two Layers of Shingles: Can it be Fixed?

Problems with two layers of shingles are real. Most homeowners may deny these facts because it’s actually too hurtful for them, but you should know that there are real issues when having this kind of roof.

Not to mention that there is a repair code (which involves building codes) that doesn’t really allow such a roof to be repaired. So, before you decide to have one, you probably need to consider some of these facts first.

Problems with Two Layers of Shingles

Two layers of shingles mean adding a second layer on top of the old one. Instead of replacing your roof completely, you retain the existing shingles and add a new layer of asphalt shingles on top.

problems with two layers of shingles

There are some different opinions about this two-layer model. Some building codes may allow it, but most of them don’t. In most cases, many of the building codes clearly forbid such construction because it’s considered risky. Moreover, although this kind of roof may be viewed as beneficial for many homeowners, the downsides exceed the positive outcomes.

Read also: Average Roof Replacement Time

It’s cheaper and faster, allowing homeowners to save money. Stripping the roof is not only time-consuming but also expensive. With multiple layers of shingles, the process is expedited, reducing costs significantly. But then again, be ready for some of these problems with two layers of shingles:

  • You won’t be able to detect damages or leaks. Because the old roof has been completely covered, you don’t have the chance to check the sheathing completely. You won’t know whether your roof suffers from leaks, rotted (or damaged) wood, algae growth, bad flashing, and others. Not only you won’t be able to see them, but you can’t fix them either.
  • Your house’s safety is compromised due to the extra weight. Adding a second layer of shingles increases the load, stressing the roof system and potentially the roof decking. This is especially risky for snowfall and heavy rain.
  • Your house can get hotter. Be logical. When there are several layers of roof on top of your head, there would be heat trapped between those layers. This extra heat will also affect the shingles, creating premature ageing.

Read also: Quick Fix for Roof Vent Leak During Heavy Rain

Can You Repair a Roof with Two Layers of Shingles?

In theory, you can always repair the roof with this kind of structure. The problem is: Are you allowed to do so? As it was mentioned before, many building codes don’t allow repair for two layers of shingles. It means that if your two-layer roof gets damaged or needs repair, you will have to replace it – NOT repair it. Legit and licensed contractors will likely refuse the repair job if you ask them to do so because they don’t want to violate the law.

The lifespan of the Second Layer of Shingles

In general and in theory, you can have around 20 years to 25 years of roof lifespan for the second layer. This is quite a long time. However, let’s not forget about the fact that it’s built on top of the existing roof. If the first roof is in bad shape, then you can’t really expect the second layer to hold up for those many years.

Conclusive Thoughts

If you are thinking about having two layers of shingles, the short-term effects may seem simple. The procedure may seem inexpensive. But let’s not forget about the long-term effects and how it can put harm your loved ones. Never underestimate the possible problems with two layers of shingles and try your best to avoid them.

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RoofLast is an experienced author and roofing expert. With years of practical experience in the field authored several informative articles on various aspects of roofing, including installation, maintenance, and repair