8 Reasons Why A Re-Roof Is A Bad Idea

By November 19, 2019Roofing Company

If you are considering a roof repair in San Jose, you are probably looking for the most cost-effective way to do it. If you have asphalt shingles, you may be considering “re-roofing” or putting new shingles over the old ones. It may seem a benefit to have a couple of layers of shingles on your roof not to mention the convenience of not having to tear off the old one. Unfortunately, the initial savings in time and money may prove to be a more costly problem in the future.

Although you may be considering a re-roof project — after all, we are allowed up to two layers of roofing here — there are some real disadvantages to consider before you decide to add shingles over your old ones.

Inspection is Impossible

Keeping your old shingles intact means that your contractor will not be able to conduct a thorough inspection of the structure underneath to ascertain any damage. A professional roofer will do a thorough walking inspection of a roof system looking for areas of concern on the decking to make localized repairs. The inability to do this may lead to more expensive and costly roof repairs in the future.

Underlayment Can’t Be Replaced

The roof underlayment, that layer of paper between the sheathing and shingles, is an added barrier when water finds its way under shingles. Underlayment can age and deteriorate which means it is no longer providing that barrier. Re-roofing with an added layer of shingles doesn’t allow for repair or replacement of damaged or worn underlayment.

Shingles Need to Lay Flat

Re-roofing means that the new layer of shingles goes over an old layer. Most composite shingles aren’t going to be able to provide good protection if they are installed over any old shingles that are cupped or curled or otherwise gapped and humped. These imperfections will often create issues with the new layer.

Added Depth

With a double layer of shingles, it’s often impossible to secure the new shingles safely and appropriately because of the thickness of the layers. Typical roofing nails may not be long enough to securely fasten the new layer of shingles.

Added Weight

Quality composite shingles are heavy and can weigh 350 to 450 pounds per 100 square feet. Most roofs are designed to withstand the weight of one layer of shingles plus a bit more for a margin of safety. Installing another layer of shingles can create a sagging issue on some roofing structures.

Negate Warranty

A re-roof can negate the warranty on some shingles. Each manufacturer has a set of installation and warranty criteria that must be adhered to in order to get the benefit of their warranty.

Future Tear-Off

When you go to eventually install a roof replacement in San Jose, tearing off two layers of shingles will be far more expensive and labor-intensive.

When You Go to Sell

If you are considering selling, having a re-roof doesn’t look good on a buyer’s inspection report. It can mean that you were looking to hide a roof issue but will also stick the buyer with a more expensive tear-off in the future. Most inspectors will warn new buyers of potential problems with a re-roof.

Hire a Professional

If you are considering a roof repair in San Jose, make sure to contact a professional roofer with a good reputation. Call Falcon Roofing at (408) 225-1705 and we would be glad to come out to your home for a free repair quote.