If your asphalt roof needs to be replaced, you may be able to have a new layer of shingles installed over the existing layer. This can help you avoid paying to have the old roof removed, but it may lead to a variety of problems down the road.
Roofers Can’t Fix Damage They Can’t See
Your current roof may have problems beneath the shingles, such as issues with the sheathing, decking and underlayment. If roofers remove the existing shingles, they will be able to perform a thorough inspection, identify problems and make repairs before they install the new roof.
If they simply add new shingles on top of the old ones, existing problems can go undetected. You may think that having an extra layer of shingles will protect your home, but that isn’t true. A house with two layers of roofing can be susceptible to damage from water and ice.
You May Have to Pay to Remove Two Layers and Make Repairs Later
If you stay in your home for a long time, you may have to replace the roof more than once. Adding a second layer of roofing now can let you avoid the cost of tearing off the existing roof, but you may have to pay to remove two layers of roofing at some point in the future.
At that time, roofers may discover significant problems that were overlooked for years, or even decades. You may save money in the long run by tearing off the existing roof now so contractors can conduct an inspection and make any necessary repairs before they install a new roof.
A Second Layer of Shingles Will Double the Weight on the Roof
A roof is designed to accommodate a limited amount of weight. That includes the weight of the roof itself, plus the weight of snow. If you add a new roof on top of the old one, you will double its weight, reduce its ability to handle snow loads and make it more susceptible to damage in the winter.
Your Local Building Code May Not Allow Another Layer of Roofing
Building codes vary from one location to another. In many jurisdictions, a roof may have no more than two layers. If your house already has two layers of roofing, you won’t be allowed to add another.
In some places, especially those prone to severe winter weather, building codes only permit single-layer roofs. If you live in such an area, you will be required to tear off the old roof before installing a new one.
A Double Layer of Roofing May Make It Hard to Sell Your House
Two layers of roofing can lead to problems or prevent issues from being detected. If you decide to sell your house and it has two layers of roofing, a home inspector will note that in the report. That may raise concerns for a potential buyer.
