Does your old commercial roof need replacing? Are you considering installing a new roof over the old one? Are you worried about choosing the right roof for your building?
We see projects where removing and disposing of the old roof is as big a job as installing the new one. The solution can lie in installing the new roofing over the existing one. There are types of commercial roofing systems that allow you to do this without any trouble. When done correctly, the finished roof is as strong and reliable as any new installation.
Let’s take a closer look at the types of commercial roofing to install over your old roofing.
TPO will install easily over the old roof
A significant advantage of TPO is puncture resistance. If you have a lot of foot traffic on your roof, then TPO is for your building.
A team of qualified roofing technicians will install your new roof and leave you with a much-improved structure.
Shingles can be difficult
We often get calls from clients looking to replace a shingle roof. A major expense can be the removal and disposal of the old shingles.
Yes, it is possible to install new shingles over an existing roof. There are many problems, however, which make the project unadvisable. Old shingles warp and leave gaps in the structure. The extra weight of the new shingles puts a lot of pressure on the roofing structure below. Even though building code allows for 2 layers to be installed, we don’t recommend it.
Shingle removal and replacement is the better option.
Putting an EPDM roof over an existing one
Like TPO, EPDM can be installed over an existing roof system. Typically, 1” polyisocyanurate insulation is installed as a protective layer between the old roof system and the new roof system. However, in some cases, when the existing roof system is a compatible single ply, new EPDM can be installed directly over the existing roof system.
Always do a roof inspection first
It is always tempting to find ways to reduce costs, and installing the new roof over the old roof can lead to massive savings. However, it is very important to make sure your roof system is a good candidate. Otherwise, you could be making a big mistake that will lead to early failures.
If your underlying insulation or roof system is wet or deteriorated, it needs to be replaced before a new roof is installed. If the underlying structural decking is rotted or deteriorated, the existing roof system needs to be removed in order to repair or replace the existing decking. A go over only makes sense when the existing roof system has not been compromised. If there are wet spots here and there, they can be replaced as needed. However, if a large portion of the underlying roof system is in poor condition, complete replacement is the best route by far.
Call in a qualified roofing inspector before making your investment.