Waterproof decking for rooftops, built to code.
Code-rated vinyl membrane for rooftop patios, multi-unit decks, and commercial terraces. Class A & C fire rated, heat-welded at every seam, 15-year waterproofing warranty backed by independent testing.
A rooftop deck is the hardest waterproofing job there is.
Rooftops face every failure mode at once: full UV, wind-driven rain, foot traffic, code-mandated fire rating, and zero tolerance for leaks into the living space below. Most decking systems aren't built for it.
Fire rating is non-negotiable
Multi-family and commercial rooftops need Class A & C fire ratings to meet building code. Most residential decking systems don't qualify.
Water has nowhere to go
Unlike a sloped roof, rooftop decks are flat or barely sloped. Standing water, ponding, and freeze-thaw cycles are constant. Any breach = direct interior damage.
Real foot traffic, every day
Furniture, pets, BBQs, planters, daily walking. A rooftop surface needs to survive 10-15+ years of actual use without wearing through or losing waterproofing.
Full UV exposure
No shade, no trees, no shelter. Any membrane that isn't UV-stabilized cracks, fades, and brittles within a few years. Most cheap deck coatings fail here first.
Drains, walls, penetrations everywhere
Rooftops have scuppers, drains, vent stacks, wall junctions, equipment pads. Every penetration is a potential failure point if the flashing detail isn't done right.
You can't easily redo it
Replacing rooftop waterproofing means tearing up furniture, planters, possibly railings. Pick a system you trust the first time.
Four pieces. Built for what rooftops put through.
Smooth-Back (60mil PVC) is engineered specifically for elevated rooftop applications — the only Valordek product with both Class A & C fire rating and a 15-year waterproofing warranty.
Smooth-Back 60mil PVC membrane
PVC-backed, Ultra Series. Engineered for elevated decks over living spaces. UV-stable, performs from −40°C to 80°C. Walks cleanly, doesn't crack, doesn't fade.
Heat-welded PVC flashing
Every wall, drain, scupper, and edge gets PVC flashing welded directly to the membrane. No caulk to fail, no tape to lift. The entire surface — including transitions — is one continuous waterproof piece.
Class A & C fire rated
Independent fire testing through Intertek. Meets the rating required by most building codes for multi-family, condominium, and commercial rooftops. Required for many municipal permits.
15-year waterproofing warranty
Backed by Valordek's parent (All Seasons Waterproofing, 25+ years in BC). Independently tested by Intertek to exceed CGSB-37.54. 5-year appearance warranty on top.
Built for the buildings that need it most.
Wherever a rooftop is finished, exposed, walked on, or rented out — Smooth-Back is engineered for it.
Multi-unit residential
Condo and townhome rooftop patios. Common-area amenity decks. Resident terraces.
Commercial buildings
Office rooftop spaces, mixed-use buildings, warehouse-to-office conversions.
Hotels & hospitality
Hotel rooftop bars, dining terraces, pool decks, event spaces.
Private high-end residential
Penthouse terraces, custom rooftop additions, finished outdoor living spaces.
What rooftop decks have to meet.
Rooftop waterproofing has stricter requirements than ground-level or balcony work — fire rating, certified waterproof testing, code-compliant flashing detail. Here's what Smooth-Back vinyl is engineered to satisfy.
Class A & C fire rating
Multi-family rooftops, commercial buildings, and most condo terraces require fire-rated decking by building code. Smooth-Back is independently tested by Intertek to Class A & C — flame spread, ignition resistance, and burning-brand resistance all evaluated under controlled conditions.
Why it matters: most residential decking systems can't qualify for rooftop installs at all. The certified fire rating is what makes Smooth-Back eligible. See the test reports →
CGSB-37.54 & CCMC listing
Tested to CGSB-37.54 (the Canadian standard for polyvinyl chloride roofing and waterproofing membrane) and CCMC-listed. Required to meet the waterproofing portion of building code when the deck sits over occupied living space.
Why it matters: uncertified systems may waterproof in the short term but fail municipal inspection and won't qualify for permitted multi-unit work. See full certification details →
Welded penetrations, drains & scuppers
Every drain, scupper, vent stack, conduit, equipment pad, and parapet wall on a rooftop is a potential failure point. Smooth-Back uses heat-welded PVC flashing — not caulk and not tape — at every transition. The membrane and flashing fuse into one continuous waterproof surface.
Why it matters: caulked systems fail at the joints first. Welded systems hold the seal until the membrane itself wears out. See the system →
Certified-installer install
The 15-year waterproofing warranty is conditional on installation by a Valordek-certified installer. Heat-welded PVC flashing requires specialized equipment and training, and the Class A fire rating is rated on the installed system, not just the membrane. DIY install voids the warranty on rooftop work.
Why it matters: rooftops over occupied space are not a project to learn on. The warranty is a service-life backstop, not a cosmetic guarantee. Read the warranty terms →
Starting at $3.74/sq ft.
Total cost depends on rooftop size, drain/wall complexity, and existing surface condition. Use our calculator to get a materials estimate in under a minute.
Try the cost calculator →Rooftop waterproofing FAQ.
What is the best waterproof decking for a rooftop?
For rooftops over living space, a heat-welded PVC membrane is the most durable option. Liquid coatings and torch-on systems both lose their seal at penetrations and edges over time. Valordek Smooth-Back combines a 60mil PVC membrane with heat-welded PVC flashing at every wall and drain — no caulk lines, no tape, no joints that fail. Backed by Intertek testing and a 15-year warranty.
What's the best waterproof decking over a living space?
Three things matter when the deck is over occupied space: (1) the membrane has to be continuous (no joints), (2) the flashing has to be welded — not caulked — at every transition, and (3) the system needs an independent waterproof certification (CCMC or equivalent) to meet building code. Valordek Smooth-Back meets all three. See the full waterproofing system →
What is fire-rated decking? Do rooftops need it?
Fire-rated decking is tested for flame spread, ignition resistance, and burning-brand resistance. Class A is the highest rating, Class C is the minimum for many residential applications. Multi-family rooftops, commercial buildings, and most condo terraces require it by building code. Smooth-Back is Class A & C rated through Intertek testing — see the certifications page.
Can vinyl decking go over an existing rooftop membrane?
Sometimes, but it depends on the condition of the existing membrane. If the old surface is intact and properly prepped, Valordek can be installed over it. If the old membrane is failing, blistered, or leaking, those areas need to be repaired or replaced first. A certified installer will assess the substrate before quoting.
How much does rooftop waterproofing cost?
Valordek Smooth-Back starts at $3.74 per square foot for materials. A rooftop project's total cost depends on size, the number of wall penetrations and drains, condition of the existing surface, and complexity of railings/equipment to work around. Use our cost calculator for an instant material estimate.
Does rooftop vinyl decking need a professional installer?
Yes. Smooth-Back requires heat-welded PVC flashing and Class A fire-rated installation — both demand a Valordek-certified installer. The 15-year waterproofing warranty is conditional on certified installation. Find a Valordek dealer in your area.
How long does rooftop waterproofing last?
Valordek Smooth-Back carries a 15-year waterproofing warranty and a 5-year appearance warranty. Real-world installs routinely last 20+ years when maintained — the UV-stable PVC doesn't degrade in sun, freeze-thaw, or normal foot traffic. Read the full warranty terms.
Sealing a rooftop deck?
Talk to a Valordek dealer about your project. We'll help you confirm code compliance, scope material requirements, and connect you with a certified installer in your area.