It is a better option than installing asphalt roofing shingles to renovate your house. Depending on the type of shingles you choose, it can add as much as 350 pounds to your home. There are some drawbacks. High-quality composite roofing shingles can be costly and may not suit every roof. This extra weight adds tremendous stress to your house and can cause the shingles to sag between the rafters. The rafters can become moist and cause decay.
Cost of re-roofing versus shingling over an existing roof
You will find many differences in the methods you use to re-roof your house. Although re-roofing might seem easier, there are important differences you need to consider before deciding. Re-roofing can be more costly. You will need to remove the existing roof and install a new one. It also increases the amount of weight on the existing roof structure, which can lead to further problems. Re-roofing can also lower the home's value, which could be an issue if it is sold. Because new shingles will be exposed, a buyer will have to tear off the two layers to get at the underlayment.
The cost of shingling on top of an existing roof can also be a difference. Although it is usually cheaper to repair an existing roof than replace it entirely, the damage to the structure beneath the shingles may be more severe. Also, shingles may not be showing any signs of damage underneath. If that is true, then reroofing can hide potential problems areas.
What are the requirements for roof replacement?
Before re-roofing an old roof, it is important to inspect the construction of the old layer. It should be completely dry, as moisture can shorten the life of the entire structure. All debris should be removed, including old shingles. Install new hips and Ridges. The nails used for ridge caps must be longer, and old metal flashing must be removed and replaced. Old penetrations must be removed, too.
It is crucial to review the current IRC and IEBC codes before re-covering an older roof. The requirements for reroofing an old roof are outlined in the IRC (International Residential Code), the International Energy Efficiency Code (IECC), and the International Existing Building Code (IEBC). They apply only to new buildings and address specifically reroofing.
Do old asphalt shingles need to be removed before they can install new ones?
It is a common myth that it is unnecessary to take out old asphalt roofing shingles before installing new ones. While it may save you money in the short term, removing old shingles can lead to problems later. You could end up with expensive roof repairs if it left old shingles on the roof. It may also result in a shorter lifespan of the new roof.
Besides the expense and time savings, it's possible to get an overlay instead of tearing off the old shingles. There are some areas that allow for two layers. However, it may not work well in your case. New shingles are less costly and will eliminate the need to inspect the sheathing for water damage. This can be very useful when your roof is damaged by windstorms, trees, or other elements.
