Every homeowner has faced or will face the issue of getting a new roof. When you are talking to your roofing contractor, one of the questions that will come up is tear-off or overlay. A tear-off is what you might expect during a roof replacement. Your contractor removes the old shingles and new ones are put into place. An overlayment is when new shingles are put in place over the old ones.
Why Would You Ever Overlay?
One of the key arguments in favor of overlay is cost. It's definitely cheaper in the short term, because you don't pay for removal and disposal of the old shingles. However, the initial savings can often disguise a much greater cost down the road. This is because most building codes only allow one overlayment. Therefore, the next time you have to have your roof replaced, you're going to pay for the removal of two layers of shingles. Additionally, overlayment reduces the lifespan of your new roof.
When Should You Definitely Not Overlay?
If your roof has multiple valleys, overlayment should never be considered as a viable option. This is because those valleys require flashing to help protect them from water and ice damage. Putting new shingles over the old doesn't allow the flashing to be inspected and replaced if need be. Furthermore, you should not put down an overlay if one is already present. This isn't just because of building codes. It's also because a layer of shingles adds significant mass to your roof. Three layers are extremely heavy, and if you live in an area prone to snow, this added mass could cause the entire roof to collaspe.
What Are Benefits to Tear-Off?
Removing all of the old shingles allows your roofers to inspect the underlayment for any damage and repair it as needed before installing the new roofing material. The roofing company you hire can then replace the flashing along the valleys and peaks, which helps prevent ice and water damage. The cost may be higher in the short-term, but the fact that overlayment reduces the lifespan of the rooming material causes the long-term pricing to be more even.
In most cases, your roofing contractor will not recommend an overlayment. There are exceptions, based on climate and the age of the home. Speak to your roofing specialist about any concerns you may have, but be aware of the long-term implications of laying new shingles over old.
For professional help, contact a company such as Angle Ridge Remodeling.