Flat roofs on commercial buildings deal with challenges residential roofs don't: rooftop HVAC units, exhaust fans, plumbing penetrations, satellite equipment, foot traffic, and ponding water. Grannis Roofing & Maintenance has the training and equipment to handle all of it across Grannis.
TPO is our most-installed commercial membrane in Grannis. White reflective surface for energy efficiency, hot-air welded seams that are stronger than the membrane itself, and 15-20 year manufacturer warranties. We install 60-mil and 80-mil systems, fully adhered or mechanically attached, over polyiso insulation.
Our Commercial Roofing Process
Free Assessment
Our inspector walks your commercial roof and documents every issue: ponding areas, seam failures, flashing deterioration, clogged drains, and UV damage. Photos and measurements provided in a report you can share with your property manager or ownership.
Project Proposal
Your proposal includes material specifications, installation method, warranty terms, project timeline, and total cost. We itemize everything and explain why we're recommending the specific system for your building.
Professional Installation
Factory-trained crews using proper equipment, hot-air welders for TPO/PVC, torch equipment for modified bitumen, and adhesive systems for EPDM. Every seam, flashing, and penetration detail inspected before we leave.
Warranty Activation
Your commercial roof gets a detailed completion package: as-built documentation, warranty certificates, maintenance recommendations, and emergency contact information for Grannis Roofing & Maintenance.
What Grannis Customers Say
"Responded fast and got the job done right the first time. Crew was polite, professional, and cleaned up everything. Would absolutely hire again."
"Best experience we've ever had with a home service company. On time, on budget, and the results exceeded what we expected. Truly top-notch."
"After getting several quotes, these guys stood out with their honesty and knowledge. No pressure, just straightforward advice and excellent workmanship."
Why Choose Grannis Roofing & Maintenance for Commercial Roofing?
Minimal Business Disruption
We schedule around your operations. Phased installation, noise management, and debris containment. Your tenants and customers barely know we're there.
Honest Assessments
If a repair or coating extends your roof's life 10+ years, we recommend that over a full replacement. We save you money when the roof allows it.
20+ Years Commercial Experience
We've been installing commercial roofs in Grannis for 20 years. Retail, warehouse, office, restaurant, multi-family. We handle it all.
All Commercial Systems
TPO, EPDM, PVC, modified bitumen, built-up, metal. We install and repair every commercial roofing system. Material selection matched to your building's specific needs.