commercial roofing
Roof Systems
Before a roof system is chosen, a core gets cut and the layers get counted. What sits on the deck in Federal Way, WA, and what the owner needs it to do over the coming years, decides the system. Single-ply membranes such as TPO, PVC, and EPDM cover most low-slope buildings. Heavier assemblies, metal panels, foam, and liquid coatings fill the rest. Each has its own tie-in details, its own dry-in rhythm, and its own weak spots.
Which single-ply fits a flat roof with rooftop units?
Heat-welded seams make TPO and PVC a common pick where many curbs and penetrations must be flashed, and KEE membrane is a PVC variant used where grease or chemicals reach the roof. EPDM is a rubber sheet with fewer seams on a large field. The choice depends on the existing substrate board, the building's exhaust, and who will walk the roof, not on a brochure.
When is a layered system the better answer?
Modified bitumen and built-up roofing build a roof in plies. They tolerate foot traffic and tie into old flashings well, which suits mechanical-heavy buildings. The tradeoff is more labor and more staging on the lay-down yard. A crew leader reviews the sequence with the superintendent before the first roll goes down.
What about metal and foam?
A standing seam metal roof sheds Federal Way rain well on steeper pitches, and a metal roof retrofit restores exposed-fastener panels without a full tear-off. Spray foam adds insulation and a continuous surface, but it needs dry weather and a protective coating. Wind loads matter, since Enumclaw saw 74 mph gusts in the November 2024 bomb cyclone, so edge securement is checked on every system.
Can a coating extend the life of a sound roof?
If the membrane is intact and the insulation is dry, a silicone coating or an acrylic coating can seal seams and slow aging. Silicone tolerates standing water better than acrylic. Both need a clean, dry surface, which narrows the application window when Tacoma logs roughly 155 wet days a year.
Commercial Roofing Questions
How do you pick between TPO and PVC?
Look at what the roof carries. PVC resists grease and many chemicals, so it suits restaurant exhaust and some industrial vents. TPO costs less in many cases and works well where the roof stays clean. We confirm the choice with a core cut and the exhaust layout.
Can a new system go over the old one?
Sometimes. A recover works when the existing insulation is dry and the deck is sound. We cut cores and scan for moisture first, because a membrane laid over wet board holds that water inside the roof.
What does wind change in the choice?
Edge and corner zones see the highest uplift, so fastening patterns and edge metal are specified tighter there. After a windstorm like the November 2024 event, a fastener pull test on an older roof shows what is still holding.
How long does installation take?
It follows the roof size, the system, and the weather. Layered systems take longer than single-ply, and coatings need dry days. The sequence is set at the preconstruction walk, with each day's opening held to what can be sealed by evening.
Send the roof plan and the schedule
Share the roof plan, the existing layers if known, and the window you have. We will walk the system choice, staging, and tie-ins with your superintendent before a number goes on paper.
