Major retrofit

The low-slope wing over the production floor had deflected enough that ponding exceeded manufacturer limits for the old modified system. The owner engaged a structural PE who specified sistered rafters and new plywood in three bays before any new membrane could be warranted.

We executed structural work under permit inspection, then installed a fully adhered assembly with walk pads at RTUs, reflective cap sheet for summer heat, and new scupper inserts tied into existing wall leaders.

Red flags we found

• Compressed fiberglass at low points — thermal bridging visible inside
• Prior patches with incompatible asphalt over EPDM-style prep
• Interior drips mis-labeled as “condensation” — active leaks at scuppers

Two-phase plan

1. Phase A — structure: Shoring inside, sister rafters, new deck, dry-in with temporary membrane.
2. Phase B — permanent: Insulation build-up, adhered cap, metal edge, walk pads, flood test where spec required.

Inspection milestones

Retrofits are never “standard.” The table documents this job’s inspection chain — yours may differ by jurisdiction and insurer.