Deck waterproofing.Managing water with intention.
Water is the biggest threat to a deck's longevity. We manage it at the framing level — directing it away from the structure so the deck lasts and the space below stays usable and dry.
Protection where it matters most.
EPDM 45-mil membrane · Framing-level water control · Part of the LeBlanc Deck System
Water is a deck's biggest threat.
Manage it deliberately, and everything above and below the deck performs better.
Left unmanaged, water accelerates wear and shortens a structure's service life. So we don't leave it to chance. We control water at the framing level — directing it away from the structure before it can sit, soak, or work its way into the build.
Above the ceiling, not below it.
Waterproofing belongs inside the framing, installed before the finishes go on. A membrane and drainage layer shed runoff away from the structure — protecting the framing, keeping the space below drier, and mitigating the premature rot that ends a deck early.
Because it lives above the ceiling and within the frame, it isn't a surface treatment applied later. It's built into the deck itself, where water is actually managed.
Three parts, one job: keep water off the structure.
Each part is planned into the framing so water is caught, carried, and kept away from the build — quietly, through every season.
Framing-level membrane
An EPDM 45-mil rubber membrane laid within the framing, before finishes, to shed water away from the structure and keep the space below dry.
Drainage & diversion
Runoff is channeled and directed away rather than left to sit — guiding water off the structure and out from under the deck.
Detailed transitions
Seams, penetrations, and transitions are detailed carefully, so water has nowhere to intrude and the system holds its line for years.
Proven materials, detailed carefully.
We standardize on a waterproofing approach with a track record for durability and flexibility in our climate, so it quietly does its job through heavy rain, seasonal change, and years of use. The name lives here so the credibility flows to the build, not the box.
- EPDM (45-mil membrane) — a rubber membrane that channels water away at the framing level and keeps the space below dry.
- Integrated drainage & detailing — runoff diverted off the structure; seams, penetrations, and transitions detailed to keep water out.
Managing the water is only half the story. Pairs with our under-deck systems to finish the space below →
Made to perform through heavy rain,
seasonal change, and years of use.
Water management earns its keep quietly. Seams, penetrations, and transitions are detailed carefully so the system holds — protecting the framing, keeping the space below drier, and mitigating the premature rot that shortens a deck's life.
Waterproofing goes in before the finishes — not after.
Because it's installed within the framing, ahead of the decking and any ceiling, waterproofing has to be planned from the start — it can't be added meaningfully once the deck is finished. It's engineered alongside the footings, KDAT framing, and mineral-based decking as part of the complete LeBlanc Deck System.
It pairs with our under-deck systems to finish the space below: this page covers how water is managed and the structure protected; that one covers the finished, usable room beneath.
The waterproofing scope carries a limited 2-Year Workmanship Warranty; a full LeBlanc Deck System build carries our transferable 3-Year Workmanship Warranty on the structure — see your contract for full terms. The LeBlanc Difference →
Right for homeowners who want the structure protected — and the space below usable.
A dry, usable space below
You want the area under the deck kept dry — for storage, a future finished room, or immediate enclosure.
A structure built to last
You want water kept off the framing so the deck ages well instead of quietly rotting from moisture.
Planned in from the start
You'd rather build water management into the deck than try to retrofit it after the finishes are on.
Pairing with an under-deck ceiling
You want the finished room below — waterproofing manages the water; our under-deck systems finish the space.
When water is managed correctly, everything above and below the deck performs better. That is the standard we build to.
Built right means built to shed water.
“Highly recommend LeBlanc Decks. Great communication throughout and even better craftsmanship. My deck project had some tricky elements to it and LeBlanc came in with a problem solving mindset. Transformed my old rotted wooden deck into a strong composite deck which I can actually enjoy.”
Water managed with intention — from the framing up.
Tell us about your deck. We'll plan waterproofing and drainage into the structure from the start — protecting the framing and keeping the space below usable — as part of one engineered system. No pressure, no obligation.
Start with a short form — we'll review your project and reach out. Serving Knoxville & East Tennessee · Licensed & insured · Backed by our workmanship warranty
Engineered outdoor structures built for long-term performance. · Knoxville & East Tennessee · Lic #79196