On a commercial building the roof is the largest surface facing the sun. What it is made of, how it is insulated, and how well it is sealed all show up on the utility bill. Here is how flat roofing choices affect heating and cooling costs.
Reflective Membranes Reduce Heat Gain
Dark roofs absorb sunlight and pass that heat into the building. White single-ply membranes such as TPO (thermoplastic polyolefin) and PVC (polyvinyl chloride) reflect much of it back, which lowers roof surface temperatures and the load on rooftop cooling units in summer.
Reflectivity drops as dirt builds up, so a periodic cleaning during routine maintenance helps a white roof keep more of its benefit.
Insulation Does the Heavy Lifting
The membrane keeps water out. The insulation underneath keeps conditioned air in. Flat roof insulation is usually rigid board installed in layers, and it can be tapered to help water drain. When a flat roof is replaced, it is the easiest time to add insulation, since everything is already open.
Wet Insulation Loses Its Value
Small leaks soak insulation and destroy its ability to slow heat flow. A roof can look fine from below while wet insulation quietly drives up energy use and rots the deck. Prompt commercial roof repair protects both the building and the insulation.
Drainage and Ponding
Water that sits on a roof for days adds weight, speeds up wear, and finds its way through small defects. Tapered insulation, crickets around equipment, and well-placed drains and scuppers keep water moving off the roof.
Air Sealing at Edges and Penetrations
Gaps at roof edges, curbs, and penetrations let air move in and out of the building. Tight metal edge details and well-sealed penetrations help the building envelope work as designed.
Rooftop Equipment
HVAC curbs are common sources of both air and water leaks. A reroof is a good time to coordinate with your HVAC contractor so units can be lifted, curbs raised if needed, and everything flashed properly.
What a Reroof Assessment Should Cover
- Membrane condition, seams, and flashing
- Moisture in the existing insulation
- Drainage and areas that pond
- Edge metal and copings
- Rooftop equipment and penetrations
Planning an Upgrade
If your flat roof is near the end of its life, replacement is a chance to improve energy performance at the same time. Request a free estimate and we will review options for your building.
