Engineered drainage.
Precision membrane work.
Flat roofing is a systems engineering challenge as much as a material application. Drainage design, membrane selection, penetration detailing, and seam integrity are the variables that determine whether a flat roof performs for 25 years or fails in five.
Flat roofing fails more often than it should — and always for predictable reasons.
A flat roof has no pitch to carry water away from vulnerable areas. Every penetration — drain, vent, HVAC curb, pipe boot — is a potential entry point. Every seam is a potential separation point. The membrane, the drainage design, and the installation quality are the system.
Apex Roofing's flat roof installations are engineered from the drainage plan up. We don't just lay a membrane over an existing substrate and call it done — we assess slope adequacy, evaluate drain placement, specify the correct membrane for the building's performance requirements, and execute the installation to manufacturer specification.
Schedule an assessmentDrainage design review
We evaluate existing drain placement and slope adequacy before specifying the new system. Ponding water is the single biggest killer of flat roof membranes.
Correct substrate preparation
Old insulation, adhesive residue, and deck defects are addressed before the new membrane is installed — not covered over.
Penetration engineering
Every drain, vent, curb, and pipe boot is detailed with correct flashing depth, membrane termination, and counterflashing to prevent chronic leak points.
Seam quality control
All heat-welded seam work is probe-tested before crew departure. No seam leaves the job without documentation that it achieved full weld integrity.
We install every major low-slope system.
TPO (Thermoplastic Polyolefin)
The most installed commercial flat roofing product in North America. Heat-welded seams, excellent UV and puncture resistance, Energy Star-rated white membrane available. 15–25 year warranties.
EPDM (Rubber Membrane)
The industry standard for 50+ years. Available in fully adhered, mechanically attached, and ballasted configurations. Exceptional cold-temperature flexibility and long-term durability.
Modified Bitumen
A hybrid asphalt-polymer system with a decades-long track record in commercial applications. APP and SBS modified options for a range of slope and temperature conditions.
Tapered Insulation Systems
Polyiso or EPS tapered insulation installed beneath the membrane to correct inadequate slope and achieve positive drainage where the original deck cannot be reframed.
Roof Coatings & Restoration
Silicone and acrylic coating systems over existing membranes in good condition. Can extend system life by 10–20 years at 30–40% of replacement cost.
Maintenance Programs
Annual inspection, drain clearing, seam maintenance, and penetration resealing — the essential maintenance program that makes the difference between 15 and 25 years of service life.
Every seam tested. Every drain detailed. No shortcuts.
Our flat roofing crews are specialists in membrane systems. We probe-test every heat-welded seam before we leave the job. Every drain and penetration is detailed with the correct flashing depth and termination method for the membrane system being installed. The substrate is prepared properly — not just covered over.
Seam probe testing
All heat-welded TPO and EPDM seams are tested with a probe tool after welding to verify full weld integrity before the crew departs the job.
Drain and penetration documentation
Every drain, vent curb, and pipe boot is photographed at completion. We document the flashing method and depth for warranty records.
Manufacturer-certified installation
We install to manufacturer specification on all warranted systems — a requirement for any warranty beyond the 5-year level.
"We had three contractors tell us the ponding water on our flat roof was 'normal.' Apex identified a drainage design problem on day one and corrected it as part of the installation. No ponding since."
"Our previous EPDM system was only 12 years old when it started failing. Apex's post-mortem showed chronic improper seam work from the original installation. Their installation is a completely different standard."
"Apex installed a tapered insulation system under our TPO membrane that corrected 15 years of inadequate drainage. The improvement in how that roof handles heavy rain is immediately visible."
From assessment to membrane warranty
Drainage & Condition Assessment
We evaluate slope, drain placement, existing membrane condition, and substrate integrity. Core samples are taken if subsurface moisture or insulation degradation is suspected.
System Specification
Membrane system, insulation type and thickness, attachment method, and flashing details are specified based on your building's performance requirements and load capacity.
Substrate Preparation
Existing membrane removal, deck inspection, defect repair, and installation of appropriate insulation system — including tapered sections where drainage correction is required.
Membrane Installation
Full-field membrane installation by certified applicators to manufacturer specification. Heat-welded seams on TPO and EPDM systems are probe-tested before crew departure.
Penetration Detailing
All drains, pipe boots, vent curbs, HVAC equipment curbs, and wall terminations are flashed and detailed to the specified depth and method for each membrane type.
Inspection & Warranty Issuance
Final seam and penetration inspection, drain flow test, and manufacturer warranty registration. All documentation delivered to the property manager or owner.
Flat roofing questions answered
Let's engineer the right flat roof system for your building.
Request a professional assessment and specification — delivered within 72 hours.