Flat roofs are a popular choice for commercial and industrial buildings because of their clean design and cost-effectiveness. However, over time, issues like leaks, blisters, ponding water, and surface cracks can develop. Knowing how to repair a flat roof the right way can extend its lifespan, prevent costly water damage, and protect your property investment.
Common Issues With Flat Roofs
Flat roof repairs often start with identifying the source of the problem. Some of the most common issues include:
- Leaks and water pooling around drains, gutters, or skylights.
- Blisters or bubbles forming under the roofing membrane.
- Cracks in sealant or caulking around flashing, edges, or penetrations.
- Damaged areas in older roofing materials such as bitumen, EPDM, or modified bitumen.
- Standing water that weakens the roof surface and leads to structural concerns.
Step-by-Step Flat Roof Repair
1. Inspect the Roof Surface
Start by conducting a careful inspection. Look for signs of a leaking flat roof, such as water stains inside the building, or surface issues like blisters, cracks, and loose roofing material.
2. Clean the Damaged Area
Remove dirt, debris, or loose material using a broom or utility knife. This helps ensure that any roof sealant, roofing cement, or patch you apply adheres properly to the surface.
3. Apply Roof Sealant or Cement
For small cracks or holes, apply roof sealant, caulking, or roofing cement with a trowel. This creates a watertight patch and prevents further water intrusion.
4. Patch Larger Damaged Areas
If the roof membrane (EPDM, TPO, PVC, or modified bitumen) is torn, cut away the damaged portion, then cover the repaired area with new roofing material. Press down firmly and seal the edges with adhesive or roofing cement.
5. Address Blisters
Cut into the blister with a utility knife, remove trapped moisture, then apply roofing cement and a patch. Smooth the surface with a trowel for a smooth finish.
6. Recoat the Roof (If Needed)
For older roofs with extensive damage, applying a roof coating (such as silicone, bitumen, or elastomeric) can restore waterproof protection and extend the roof’s life.
DIY vs. Hiring a Roofing Contractor
While some homeowners and property managers attempt DIY flat roof repairs, it’s important to weigh the risks. Incorrect repairs may void your warranty, shorten the roof’s lifespan, or cause more extensive damage.
A certified roofing contractor can:
- Provide regular inspections and maintenance.
- Recommend when roof replacement is more cost-effective than repeated patching.
- Use professional-grade roof coatings and materials that deliver long-term watertight protection.
Protect Your Roof With Regular Maintenance
Flat roofs need consistent care to avoid costly repairs. Regular inspections, gutter cleaning, and timely repairs for small leaks prevent larger issues like water damage, ponding water, or structural failures.
If your flat roof shows signs of damage or leaking, don’t wait until the problem worsens.
Keep Your Flat Roof Performing at Its Best
Southwest Commercial Roofing specializes in flat roof repair, roof replacement, and preventative maintenance for industrial and commercial properties.
Request a complimentary roof inspection today and learn how our certified experts can keep your roofing system watertight and long-lasting.
