Elk Grove Roofing: Article About New Shingles Over Old
In certain reroofing scenarios, it is possible for an Elk Grove roofing company to install a new roof over existing roofing materials. Avoiding a tear off can reduce installation costs and time, but there are many disadvantages to the process. Generally, laying new shingles over old is only a reasonable option when dealing with asphalt shingles. It is also never a good idea to combine roofing materials, so laying slate over asphalt or asphalt over metal is an unacceptable practice than can cause many problems, such as leaks and structural weak points.
It is important to note that the advantages of this method include reduced costs and installation time. However, there is little evidence that suggests that additional asphalt layers protect a roof any better than a single layer. Aesthetics should also be considered. If the current shingles are uneven, then that could result in unevenness in the top layer, making for a roof that looks sloppy and that may not be structurally sound.
Weight is also an important consideration. A roof is only designed to bear so much weight, and each layer adds additional weight. A second layer is essentially double the weight.
The roofing contractors at Allstate Roofing of Elk Grove can assist you with any questions regarding skylights or storm damage.
For this reason, it is not advisable to add any layers beyond a second. In addition, it may not be practical to add a second layer at all if the new layer is heavier than the first, such as installing architectural asphalt shingles over 3 tab asphalt shingles.
Perhaps the biggest concern that professional roofers have with layering over a tear off is the diminished ability to inspect the roof. When a tear off occurs, the inspector has access to the sheathing and other fundamental aspects of the roof structure. If any damage has occurred, then it is crucial for the contractor to perform repairs and maintenance. When applying a new layer to an existing one, the roofer never has access to the sheathing, and if there is damage, that damage can become worse over time despite the new roof.
Homeowners should note that local code may not allow reroofing without tear off, and even if the local code does, it may have specific limits on weight and layer count. Nearly all manufacturers of roofing materials recommend against multiple layers, and choosing to do so may affect any warranties. Homeowners should also keep in mind that a layered roof may lower a home's value and discourage potential buyers if it is ever put on the market.