What You Need To Know About Extra Layers Of Shingles

Your roof has faithfully protected your home from external elements and all Mother Nature has to offer, but now you have all the signs it’s time to get a new roof. Did you know tearing off the old roof and starting over isn’t your only option? Yes, in some cases, it may be possible to shingle over your existing roof, though it isn’t always recommended.

What Reroofing Involves

Re-roofing involves placing new shingles directly on top of your existing roof. This might be a great option if the current roofing materials are in good condition but a few repairs will not be sufficient to get your roof back into shape.

The Pros of Reroofing

  • Leaving the old shingles in place is considerably cheaper because you will minimize the removal, cleanup, and disposal expenses.
  • Since reroofing does not require stripping existing shingles, it will basically take less time to finish – great if you have a limited budget for alternate lodging or just want a new roof quickly.
  • The extra layer of shingles will act as a secondary barrier against leakage and wind damage.

The Cons of Reroofing

  • As shingles are just laid over the old ones, they may not reach their full life expectancy due to the absorption of heat trapped by the multiple layers, which can cause the shingles to break down or curl.
  • Installing new shingles on top of a weathered, uneven roof may not be as visually appealing as a brand new roof would.
  • Due to the old shingles being left on, you don’t get the opportunity to see what’s underneath. A roof inspector might notice an issue by just walking on the roof, but this will not reveal the exact condition of the other layers, which means any damage such as rot or sagging will not be fixed. If the underlayment is old and deteriorated, the extra layer of shingles provides little protection against water damage.
  • Reroofing adds significant weight to the top of your home. This can cause the roof sheathing to sag between the trusses and rafters.

When Reroofing is Not a Good Idea

Reroofing is not an option if your roof is already covered by two layers of shingles. Building codes typically prohibit the installation of a third layer because the roof can get too heavy.

Even if you have a single layer of shingles, you should not cover it if the underlying structure cannot support another layer. Your roof structure may have been designed to support one layer of shingles, so doubling the weight may compromise the integrity of your roof and home’s structure.

If your existing shingles are curled, cupped, or missing you may want to consider roof replacement because shingles are designed for completely flat and level surfaces. What’s more, you shouldn’t add an extra layer of shingles if there’s extensive and visible damage or the majority of your roof feels soft and spongy. The best option is to tear everything completely off and fix the damage to avoid constant repairs or premature failure.

Contact us at S&S Roofing in Arlington, WA, to schedule a roof inspection. Our team of highly trained roofing technicians can evaluate the condition of your roof and help you make the best decision.