If you are looking to fix a leaky commercial roof that is flat, and you don't want to tear it up and redo it, there are different things that you can try. You'll want to talk with the roofing contractors about the types of damages that the roof has, and what materials need to be replaced because of water damage. Be sure to talk with the roofing contractors about these things.
Foam Spray Roofing
Ask the commercial roofing company if spray foam application is an option to stop the problems that you're having with leaks. The spray is a polyurethane foam that expands and fills the cracks and crevices around the roof, along with protecting the roof from rain, snow, ice, and pests. This is easy to apply and can help with heating and cooling costs.
Layer of Asphalt
If asphalt was originally used to coat the roof, another layer of asphalt may be the easiest way to fix the problem. Have an asphalt company come to give a quote to put another layer of asphalt on the roof, and to see if this roof can handle the weight of another layer of asphalt.
Don't ignore any interior repairs that are needed from the water leaking, such as mold or mildew growth. Leaking water can also cause wood to rot. Just because the roof is repaired doesn't mean that the building materials are repaired, so take the time to treat them as needed.
Exterior Building Concerns
If the water was leaking there could be problems around the exterior of the building to. Often, it's easy to notice water damage inside, but unless you are in the air near the roof of the building you may not notice the exterior damages. Have the exterior examined and repaired while the roof is repaired as well.
You don't want to let a leak go in your commercial property, and if you have a flat roof there are a few different ways that you can let the roofing contractors fix it. See if the roof can be saved and if the spray foam or the layer of asphalt will be a quick and affordable fix.
The roofing company that offers foam roofing system installation services will be able to asses if you need major repair work, or if adding a new top layer is the answer. Get quotes and estimates so you can pick the best choice.