What Makes Up Your Roofing System?

Your roofing system is only as good as the weakest link.

What makes up your roofing system? A question I’m sure you’ve been pondering for a while now! Well, we’re here to tell you the in’s and out’s of the flat or low-slope rooftop on your commercial building. Although it’s not the most glamorous knowledge, when you’re face-to-face with an issue, you’ll be glad you know! Typically, flat or low-slope roofing systems are made up of three main components: decking, insulation, and membrane. They all serve a fundamental purpose and come together to keep your roof protected from the elements it will encounter throughout its lifetime.


Decking is perhaps the most important part of your commercial roofing system; without a solid foundation, your roofing system will fail. A good foundation can truly eliminate a lot of the problems we face on a day-to-day basis. Not only does the decking provide support for the rest of your roofing system, but it can also help with thermal performance, fire resistance, drainage, and wind-uplift performance. The importance of solid decking mustn’t be lost on your contractor when designing your new roofing system.

As a property manager or building owner, it is important you know what deck is on your building and what condition it is in, especially if you plan on completing a roof replacement or retrofit in the near future. Here are a few things to keep in mind: 

  1. What material is on your roof currently, or what material will you be using? Common materials we see are steel, wood sheathing, and plywood/OSB. 
  2. What is the condition of your roof deck? If it is corroded, detached, damaged, or deemed unsafe, your contractor will likely want to replace it. If you aren’t aware of that ahead of time, it can get costly. 
  3. If the decking is damaged or needs to be repaired in the future, can you only pull out the necessary spots and leave the rest alone? Important to note if you are on a budget!
  4. Is your current deck capable of holding your new roofing system? Sometimes the new system you choose and/or want to choose won’t be compatible with your existing deck. Selecting the right contractor can help with that.

I bet you didn’t think decking would give you that much to think about, did you!