Roof Deck Installation and Repair, Membrane First
Roof deck jobs at Foundry Roofing are built from the membrane up: we install, repair and replace rooftop decks on flat and low-slope roofs across Queens. The waterproofing under the deck meets manufacturer spec before any paver goes down.
We build on multi-family buildings, co-ops, condos, mixed-use buildings and brownstones.
We walk the roof and price the deck and membrane together.
Layer by layer
Six layers between your deck and the ceiling below
The decking is only the top layer. The roof under it keeps water out of the building.
- 01
Deck surface: pedestal pavers, composite or wood decking, railings at the edge.
- 02
Pedestals or sleepers, lifting the surface so rainwater runs beneath.
- 03
Protection board to keep pedestal feet from puncturing the membrane.
- 04
Waterproofing membrane: TPO laid under the deck, EPDM or modified bitumen, flashed up the parapet walls.
- 05
Insulation with a tapered slope that sends water to the roof drains.
- 06
Structural decking, wood or steel, carrying the whole stack.
Matched to your roof
Matching the job to the roof you have
| Situation | What we do | Reused | Warranty point |
|---|---|---|---|
| New rooftop deck on an existing roof | Load check and membrane work, then install | Existing membrane, if sound | Built to the membrane maker's rules |
| Leak or water damage under a deck | Deck removal, membrane repair once the deck is lifted, reinstall | Pavers, pedestals, decking in good shape | Leak source and repair documented |
| Worn deck over an aging membrane | Full roof deck replacement, new membrane and flashing | Sound railings and pavers | Fresh manufacturer membrane warranty |
Pre-build checks
What we check before building on top
Rooftop amenity space adds planters, furniture and daily foot traffic to a roof built to shed water. So we inspect the building before a roof deck goes on.
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Load
Load capacity and structural support, with rotted structural decking replaced first
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Drains
Roof drains kept reachable under removable pavers
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Parapets
Parapet height against railing rules, and flashing on the walls
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Access
Roof access for residents, plus a clear path for future roof work
FAQ
Leaks, warranties and load: what owners ask
Can you fix a leak without tearing out the whole deck?
Yes. Pavers and sleeper-mounted decking come up in sections, so we lift only the area over the leak and reset the same pieces.
Will a deck void my roof warranty?
Only if it goes on wrong. Membrane manufacturers require protection board and approved supports, and we build to those rules.
Can my brownstone or rowhouse roof carry a deck?
Often, after a structural check. Older joists may need sistering or new decking first, and you hear that before any price.
Free estimate
Book a free look at your deck and roof
Your estimate covers the deck, the membrane under it and the drains, priced as one job after we walk the roof.