How to Determine if You Can Recover an Existing Roof
Considering a recover? There are loads of advantages to installing a new roof over an existing one:
- It’s less costly because you’re not paying labor and landfill fees for the demolished roof.
- It provides excellent thermal performance since the existing insulation is supplemented by a new layer of insulation.
- You don’t need to worry about interior protection since the existing roof remains in place during the project.
- Project duration will be shorter since the old roof does not need to be torn off.
But can you do it? That’s a whole other question. There are three factors that influence your roof’s eligibility for this kind of project.
No. 1 Condition of the Existing Roof System
You should not recover the roof system if it has a history of leaks, the presence of moisture, or damaged insulation (either because it was crushed from repeated foot traffic or has deteriorated from long-term moisture exposure even if it’s currently dry). A weak deck (e.g. if the steel deck is corroded or wood deck is deteriorated) also makes recover impossible.
To check the condition of the substrates, a visual inspection of the underside of the deck, core samples, and/or infrared thermography may be used by your roofing contractor.
No. 2 Applicable Building Codes
Check building codes to see what the restrictions are. It’s important that the recover still meets specified requirements for wind uplift and fire ratings. Most building codes only allow you to have two insulated roof assemblies on a facility. Depending on how the code is interpreted, you might be able to add another layer of membrane (with no insulation) or more plies of felts and asphalt to an asphaltic roof; this is sometimes considered a repair.
No. 3 Structural Load
Your roofing contractor can determine the weight of the existing roof components and the proposed roof system, but an engineer will have to determine what the structure is capable of holding. If the recover involves the removal of gravel or pavers, it’s not likely your roofing contractor will be putting back as much weight as was removed.
Your roofing contractor can help determine the eligibility of your roof for a recover project, the length of the warranty you’d get, and the means and methods required for roofing over an existing system. Lean on them to help you evaluate the feasibility and discuss the best type of project for optimum roof performance.
Call D. C. Taylor Co. at 319.363.2073 to discuss your roofing project options today.