Commercial roofs rarely fail all at once. They fail one clogged drain, one split seam and one forgotten rooftop unit at a time. The building owners who get the longest life out of a flat commercial roof are not the ones with the most expensive membrane. They are the ones who have someone look at it on a schedule.
Here is the maintenance checklist we recommend for flat and low-slope commercial roofs in New Jersey, whether you own a strip of storefronts, a small office or a warehouse.
How often to inspect
- Twice a year: once in spring after the freeze-thaw season, and once in fall before leaves and snow.
- After every major storm: high winds, hail or heavy snow loads.
- After any rooftop work: HVAC techs, sign installers and satellite crews are hard on roofs.
The checklist
Drainage
- Clear drains, scuppers and gutters of leaves, debris and nesting.
- Look for ponding water 48 hours after rain. Standing water speeds up aging and stresses seams.
- Check that drain strainers and clamping rings are in place.
Membrane and seams
- Look for splits, blisters, punctures and open seams.
- Check for shrinkage pulling the membrane away from walls and edges.
- On EPDM, pay extra attention to taped or glued seams.
Flashing and edges
- Inspect wall flashing, parapet caps and metal edges for gaps or loose fasteners.
- Check sealant around penetrations, which dries out and cracks over time.
Rooftop equipment
- Check curbs and flashing around HVAC units, exhaust fans and skylights.
- Look for screws, panels and debris left behind by service technicians. They puncture membranes.
- Make sure condensate lines drain to a drain, not onto the roof.
Inside the building
- Walk the top floor and look for ceiling tile stains, rust on deck, or musty smells.
- Note the location of any leak and pass it on to your roofer. Leaks travel on flat roofs too.
Keep a simple roof log
Write down the date of every inspection, repair and leak, with photos. A log helps your roofer spot patterns, helps with insurance claims, and helps you plan the budget for replacement instead of getting surprised by it.
Signs it is time for more than maintenance
- Leaks in several places at once.
- Large areas of wet insulation under the membrane.
- Membrane that is brittle, cracked across the field, or patched over and over.
At that point, a restoration or replacement usually costs less than chasing leaks. Our guide to common commercial roof types in New Jersey covers the options, and TPO vs. EPDM compares the two most common membranes.
Frequently asked questions
How long does a commercial flat roof last?
It depends on the system, the installation and maintenance. Roofs that are inspected and kept draining well last far longer than roofs that are only looked at when they leak.
Who should be allowed on the roof?
Limit access to people who need to be there, and ask HVAC and other contractors to report any damage they cause. Walkway pads to rooftop units help a lot.
Can a leaking commercial roof be repaired instead of replaced?
Often, yes. Most leaks come from seams, flashing or penetrations that can be repaired. A full replacement makes sense when problems are widespread.
Need a commercial roof inspection?
Herts provides commercial roofing inspections, repairs and replacements for building owners across New Jersey. Call 908-206-4240 or request an inspection.