An overlay may seem like a good idea, since it’s cheaper and takes less time. When you consider the long-term, however, doing a tear-off before installing the new roof makes much more sense.
An Overlay Doesn’t Reveal Decking Damage
Many professional roofers will tell you that an overlay is perfectly acceptable (if you have only one layer of roofing), and will result in very little or no damage to your deck structure.
Theoretically, that is indeed true. Unfortunately, it is virtually impossible to know for sure whether you have decking damage unless you remove the old roof.
By the time most homeowners need a new roof — usually decades after the last one was installed — moisture accumulation often has caused water damage, dry rot and deterioration in the decking. Removal of the old material is the only way to inspect the decking, or to determine if any damage requires repair.
If you choose to go with an overlay despite the risk, know that your new installation may not protect your home as well from future leaks.
A Tear-Off Extends the Life of Your New Roof
Due to issues of structural integrity, new roofing will last longer if you tear off the old roof.
With a tear-off, all of the old material (shingles and underlayment) is removed and discarded. When the new material is added, the weight on the decking remains constant. If you don’t have the old material removed, it doubles the structural load on your roof.
Depending on the size of your home, you may add much more weight to what is already there. This extra weight can stress the decking as well as the structural roof supports, leading to a shorter life span for your roof.
A New Roof Can Boost Home Value
A new roof is an ideal upgrade for attracting home buyers. But if the buyer’s home inspection reveals multiple layers of roofing material, it can raise red flags. In fact, buyers may turn away, wary that the roof has a greater potential for future leaks.
In many parts of the country, including Utah, building codes only allow for a maximum of two roof layers. So if yours has already had an overlay, you will likely be required to remove the old material next time. Beyond the building codes, however, new system warranties may not cover overlays, due to liability for installation over a potentially damaged structure.
The experienced team at Knockout Roofing offers free estimates for professional roof tear-offs to homeowners throughout the greater Salt Lake City area. Call our office today to schedule an expert consultation to discuss the best approach for your new roof.