Project 04
Flat roof re-covered in EPDM
A ponding felt roof stripped and re-covered in one-piece EPDM over new firrings, so the water reaches the outlet instead of sitting over it.
The problem, and the number
The deck was dead level and the outlet was, as it usually is, at the high point of the ponding rather than the low one. New firrings were cut to build a designed 1:40 across the deck so that the finished fall still clears the 1:80 that BS 6229 asks for once deflection has had its say.
The EPDM went on in a single sheet, so there are no field laps on this roof at all. The work is in the upstands and the outlet, which is where every flat roof we are called back to has actually failed.
Scope: strip, firrings, EPDM, outlet, perimeter trim
- System
- EPDM 1.2 mm, single sheet
- Falls
- New firrings, designed 1:40
- Laps
- None in the field, one-piece membrane
- Fixing
- Fully adhered
- Outlet
- Relocated to the low point
- Completed
- May 2024
