When it comes to investing in a new roof for your commercial building, you may be struggling with whether to tear off the existing roof or just have the new roof installed over it. It goes without saying that if your current roof were functioning well, you probably would not be investing in a new one. Even if you are putting on a new roof as part of a building make-over to improve occupancy rates or for some other reason, a new roof is going to function much better for you over the long haul if you tear off the old roof first.
Installing a new roof over a damaged or leaking roof may solve your problems (in your dreams). In fact, what a new roof will actually do is further trap any moisture that currently exists in your roof deck and other substructure components, potentially creating mold heaven and a propensity for some really nasty leaks or structural repair after a heavy snowfall or in other inclement weather.
The advantages of a commercial tear off of your old roof prior to installing a new one are three-fold, at minimum. Any structural defects in the roof deck will be revealed and repaired; if condensation is located, proper ventilation can be installed to help eliminate current and future moisture; and, weatherproofing can be installed prior to the re-roofing to protect against leaks in the future.
If this were not enough, a new roof placed directly on the roof deck will last longer, be in-line with the roofing system warranty, and decrease the weight of your roof load. Add the fact that new roofs are generally more energy efficient that their predecessors and you have a heck of a lot of reasons to have the job done right the first time!