Many commercial buildings have flat roofs. They are less expensive to build and install than sloped roofs, are more readily accessible and safer to walk on, and provide more space for HVAC systems. Of course, all of this means that there are some special considerations when planning to have one installed, repaired, or replaced. It would be best to contact a commercial roofing contractor and discuss what is needed. They will come inspect the building and go over what needs to be done. Here are a few things you should be sure to discuss so the roof will be strong, stable, and durable for years to come.
Load
Commercial buildings often require a lot of equipment on the roof. The HVAC system for a single business is usually much bigger and heavier than one for a residential building. If there are a number of businesses in the building, there will be as many systems. Some businesses require more than a unit for heating and cooling the place. They may have multiple units and then systems for fire suppression, refrigeration, and maybe even some of the plumbing pipes will need to go on the roof. The contractor needs to know exactly what is going to be on the roof so they can design one strong enough to hold it all.
Drainage
A flat roof is not completely flat. There must be a bit of a slope to allow for rain and melted snow to flow off of it. Of course, snow will sit longer on a flat roof than one with a steep slope, so it is important to have a solid, impermeable membrane under any roofing materials to prevent water and moisture from seeping into the roof structure and destroying it. It is also imperative to have a drainage system in place that diverts the water from the roof as soon as possible. This could include a tapered insulation board placed on top of the membrane causing the water to flow directly to gutters and drains.
When the load and drainage issues are properly considered, a flat roof can last for many years with proper upkeep. You should make sure to have someone go up on the roof and inspect it after heavy storms of any kind and to have it swept of any debris that may not roll off the roof due to the lack of a slope. Luckily, the lack of slope makes it easier for a roofing contractor to get up and work on it.
