When Replacement Is the Right Call
Recover-versus-replace is the first decision in any aging-roof scope. We pull moisture cores in five to ten representative locations on roofs we suspect have insulation saturation. If more than 25% of cores read wet, replacement is the honest scope - recovering wet insulation traps the moisture and voids the new warranty. If under 25%, a recover with targeted insulation replacement at wet areas can extend the asset another 15 to 20 years at roughly half the capital cost of full replacement.
Deck condition is the second decision. We pull deck inspection ports under wet cores and at deflection points. Corroded metal deck or rotted plywood means deck replacement, which changes the project cost band and sequencing plan. Owners need to know this before the project starts - not when the crew opens up the roof and stops work. In older St Louis commercial buildings - particularly pre-1980 construction along Olive Street or in the Clayton CBD - we find deteriorated deck more frequently than in newer Sun Belt markets.
What the Replacement Scope Specifies
Membrane: TPO 60-mil or 80-mil for most St Louis commercial buildings; EPDM 60-mil for industrial and buildings with high mechanical traffic; PVC 50-mil or 60-mil for restaurants, chemical exposure, and medical buildings; modified bitumen for buildings with existing BUR systems where the recover path makes sense. We are manufacturer-agnostic - we specify based on building use, manufacturer warranty terms, and what the building's capital horizon supports.
Insulation: We spec to current Missouri energy code. The stack typically runs polyiso primary insulation plus a cover board (HD polyiso or gypsum depending on membrane). Tapered insulation packages are designed against the existing drain layout and the actual ponding patterns we documented during inspection. In St Louis, positive drainage is not optional - flat or near-flat areas that pond water are also the first areas to fail when ice forms.
Fastener pattern: Designed against IBC wind-uplift requirements for the building's zone and exposure category. St Louis sits in a derecho corridor - straight-line wind events with sustained speeds above 70 mph that challenge mechanically attached systems on large, open roofs. We do not underspec fastener density.
Project Sequencing in the St Louis Market
Pre-construction: Permits filed with the relevant municipality - City of St Louis, Clayton, Chesterfield, Hazelwood, or the relevant county authority. Pre-job meeting with the building's facility manager to set crane and material lay-down zones, tenant notification distributed, and parking and access impact documented.
Production: Tear-off staged in 5,000 to 10,000 sq ft sections with priority dry-in on each section, so the building is never exposed overnight. St Louis spring weather is unpredictable - we monitor radar and stage production to pull tear-off work back if a squall line is tracking toward the metro.
Closeout: Punch walk with the building's facility manager and our project manager, manufacturer warranty inspection with the manufacturer's field rep, closeout package delivered (warranty document, photo-keyed zone diagram, maintenance contract, manufacturer start-up documentation).
