Roofing SOP Example

Flat Roof TPO Membrane Installation

Commercial flat roof TPO install over insulation with heat-welded seams and penetration details.

1. BUR removal & deck inspectionRemove existing gravel ballast to dumpster. Mechanically remove BUR membrane — do not use open-flame torch near exposed wood deck. Inspect steel or concrete deck for rust, delamination, or structural damage. Photograph all deficiencies and notify project manager before proceeding. Deck must be clean, dry, and free of debris before insulation installation.
2. Tapered insulation installationInstall polyiso insulation boards per project drainage plan — ensure positive slope to all drains (minimum 1/4" per foot). Mechanically fasten per FM Global or manufacturer requirements for wind uplift zone (typically 1 fastener per 2 sq ft in field, doubled at perimeter and corners). Offset board joints by minimum 6". Do not allow gaps between boards.
3. TPO membrane installationRoll out 60-mil TPO sheets in the direction of positive drainage. Allow membrane to relax for minimum 30 minutes in temperatures below 50°F. Mechanically fasten at seam laps per manufacturer pattern. Maintain minimum 6" seam overlap. Begin at low point of roof and work toward high point to allow proper drainage during installation.
4. Seam weldingHeat-weld all seams with hot-air welder set to manufacturer-specified temperature (typically 950–1100°F depending on ambient conditions). Test weld width — minimum 1.5" continuous bond. Probe every seam with rounded metal probe immediately after welding. Any seam failure must be repaired with a patch extending minimum 3" beyond defect in all directions. Log all seam inspections.
5. Penetrations & edge metalInstall prefabricated pipe boots at all mechanical penetrations. Heat-weld base flashing to field membrane — do not use membrane adhesive at seams. Install edge metal and cleat at perimeter per manufacturer detail. Seal edge metal laps with membrane tape and heat-weld. Install drain sumps at all roof drains — ensure sump is set 1/4" below finished membrane level.
6. Final inspection & warranty submittalFlood test all new drains for minimum 24 hours where feasible. Photograph all penetrations, seams, edge conditions, and drain details. Complete manufacturer inspection walk if required for full warranty. Submit completed installation documentation, fastener pull test results, and welder certification records to manufacturer for warranty processing. Provide copy of all documentation to building owner.