Dallas Roofing: Article About Two Roofs Aren't Better Than One
Most Dallas roofing contractors will never recommend a second shingle layer. The ideal way to install a new roof is to tear off the old material, prepare the sheathing, install the underlayment, install the flashing and finally install the shingles. When new shingles are installed over old, it forfeits the chance to inspect and prepare the sheathing, underlayment and flashing. That being said, laying a second layer of asphalt or fiberglass shingles is an option, and it is even allowed by many building codes.
A homeowner may opt for a second shingle layer in order to lower expenses and reduce installation time. A tear off does cost money and take time, but it is worth it. Consider that a roof plays an important role in curbside appeal, and a single layer roof simply looks better. A two layer roof will often appear unnaturally thick, and there will be an unsightly seam between the layers that will likely be visible from the road and certainly up close.
Some homeowners may believe that two times the shingle thickness equals two times the protection.
The roofing experts at Total roofing of Dallas TX can assist you with any questions regarding residential roofing or roof maintenance.
However, two layers of three tab doesn't have the same durability as a laminated shingle, and there's no evidence that a second shingle layer actually provides better protection against rain, wind or hail. There's also a weight consideration. A second layer adds to the weight load of a roof, and if roof weight exceeds the dead load limit, it can lead to damage.
The biggest concern a homeowner should have with forgoing the tear off is the inability to inspect the roof and to replace support materials like underlayment and flashing. Flashing doesn't last forever, and when it fails, it will undermine the roof regardless of how many layers it has. Therefore, any savings that homeowners gets from skipping the tear off can actually be lost in added maintenance and reduced roof lifespan.
There are a number of other factors to think about before installing a second roof layer. If selling the home in the future is a possibility, then a roof installed this way won't be a selling point. Building codes don't generally govern what a homeowner can or can't do to his or her home, but if local code doesn't allow it, then a home inspector can fail the home based on that, and even if the local code does allow it, the inspector may simply recommend that the prospective buyer avoid the home or demand a new roof.