Roofing Projects that Don’t Require Total Tear-Off
Not every roofing project requires full-scale demolition. The smallest of these projects is a modification or retrofit. You can add accessories (e.g., grease guards), skylights, fall protection equipment, a snow retention system, new penetration, and walkway pad without doing any tear-off of the roof system at all. Just remember to always use a professional roofing contractor who is an approved applicator of the roof system you have and notify the manufacturer of the work being done to prevent voiding the roof system warranty.
There are three other types of roofing projects that don’t require total tear-off. Keep reading for more on those.
Recover
A recover project leaves the existing roof in place and installs a new roof system over it. This is only possible if:
- The condition of the roof is good (e.g., without evidence of deterioration on the deck and no crushed or wet insulation).
- Building codes allow recover. (Typically, codes only permit two insulated roof assemblies on a facility. If two roofs are already in place, sometimes the oldest can remain, the top one can be removed, and a new roof system installed.)
- The structural load can accommodate the additional weight of two roof systems.
As opposed to a total tear-off and reroof, a recover project is likely to be less expensive and shorter in duration. Recover is also a more sustainable option. As the existing roof system probably still has some R-value, the new roof system will require less insulation.
Partial Recover
It’s not uncommon if you have a metal roof to do a partial recover project. In this instance, your contractor will add flute fill insulation between the metal ribs, add coverboard, and apply a single-ply membrane. At the place where the new membrane roof system stops, membrane is installed over the rib, caulked, and secured with a termination bar and screws. (To learn more about membrane-over-metal projects, click here.)
Partial Reroof
If the budget is limited, removing and installing a new roof on a portion of the building is possible. It’s not uncommon to divide a project in half and complete it over two years to spread out the expense. A partial reroof is also ideal if the roof is leaking in one area and wet insulation is isolated there. The portion of the roof that remains in place should be in good condition though.
What makes these projects different is the tie-off. Roof system manufacturers will not warrant this area where the new roof ties in with the existing roof (only the field of the roof will be covered). The reason is simple. If not done properly, water can run under the new roof system, making it seem like faulty workmanship is to blame for the leaks.
Your roofing contractor is likely to join the new single-ply roof to the old one in one of two ways. They will either 1) try to tie off the new roof down to the deck and add another piece of membrane joining the two roof systems via heat welding or 2) use a control joint. In the latter situation, a 2 x 12 piece of wood would separate the new roof from the old one. The roofing contractor would take the new roof membrane up and over and do the same with the old membrane for a watertight seal.
Your roofing contractor can help you determine if your roof is a good candidate for a recover, partial recover, or partial reroof project. The condition of the roof is the most important factor in eligibility. Make sure you partner with an experienced roofing contractor who can make sure these projects, because they are more complicated, are done properly to ensure a watertight roof.
Contact D. C. Taylor Co. today at 319.731.4118 or by emailing [email protected] to schedule your next roofing project.
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