When deciding between overlay and tear-off for fiberglass shingles, it’s important to understand what each option involves. An overlay means installing new shingles directly over the existing roofing layer. This can be a quicker and less expensive route, suitable when the original roof is in decent shape without multiple layers or severe damage. However, overlays add extra weight to the roof deck and can hide issues like rot or weakened underlayment. Tear-off involves removing the old shingles completely before installing new ones, allowing a full inspection of the roof deck and any needed repairs. This option is usually better if the existing roof has more than one layer of shingles, significant damage, or is nearing the end of its life. It often results in a longer-lasting roof and avoids potential problems caused by trapping moisture.
For a simple DIY check, look for signs such as curling, cracking, or many missing shingles on your current roof. Step into the attic and check for daylight coming through the roof boards or water stains, which suggest leaks beneath the surface that overlays could worsen. Also, consider your local building codes—many limit overlays to just one existing layer. When you call a roofer, ask about the condition of your current roof deck and whether it supports an overlay. A good question is, “Are there any hidden damages you expect to find once the old shingles are removed?” Also, inquire about how the warranty will be affected depending on the method they recommend. This clarity will help you choose the lasting and safest solution for your home.