Frequently Asked Questions
What specifiers, owners, and applicators ask about traffic-bearing deck systems.
Load, Traffic & Thickness
How do I know what load class my deck falls into?
Start with the heaviest thing that crosses it and how much of the traffic turns in place. Pedestrian-only decks run 40–60 mil. Light vehicle traffic runs 80–100 mil. Heavy equipment, forklifts, and any area where steered wheels turn while nearly stationary run 100–120 mil. Ramps and turning bays get the top of the range even when the flat deck does not, because slope plus steering shear is the worst combination on a deck.
Why does turning traffic matter more than straight-line traffic?
A wheel turning while nearly stationary applies torsional shear through the contact patch — an in-plane twisting force rather than a rolling one. That force goes straight into whatever bond line is weakest in the system. It is why parking deck failures cluster at ramp turns and stall entries rather than in the middle of a drive lane, and why tear strength and adhesion matter more than surface hardness on a trafficked deck.
Will the membrane crack as the deck deflects under load?
No. At 300–400% elongation with 400–500 pli tear strength, the membrane follows live-load deflection, thermal movement, and vibration rather than resisting them. That is the reason a traffic-bearing deck system is specified on elastomeric properties instead of hardness — a hard film on a flexing steel deck is a fatigue crack waiting for enough cycles.
Is the membrane thick enough to be a wearing surface on its own?
Yes, and that is the design intent. At 100% solids the material sprays 20–120 mil in a single pass with no shrinkage, so the wearing course and the waterproofing plane are the same continuous film with a graded build. There is no separate topping, no inter-coat bond between two different systems, and no seam between them to fail.
Traction, Joints & Details
How is skid resistance achieved, and does it wear off?
Aggregate is broadcast into the wet membrane and locked in place by a second pass, so it is embedded in the film rather than sitting on top of it. It wears with the membrane instead of separating from it, and it cannot peel or lift an edge the way applied non-slip tape or a broadcast-on-cured-film approach can. Grade is selected by traffic class — the coarsest goes on wash bays, ramps, and marine decks.
What do you do at expansion joints?
The membrane is terminated into the joint detail rather than sprayed blindly across it, and the movement capability of the assembly is confirmed against the design movement range beforehand. The deck is designed to move at that line, and a membrane bridged across an expansion joint without a proper detail is simply a coating that will be torn open by the movement it was placed over.
How are drains and penetrations handled?
The membrane is carried into and through the drain body so the waterproofing plane terminates below the water line. A membrane stopping at a drain flange puts a seam at the lowest point on the deck, which is exactly where water stands and where it will find its way through. Column bases, bollards, and rail posts are primed with 7001 and coved, and typically get additional local build because they also take vehicle impact.
Does the deck need to drain, or will the membrane handle ponding?
Polyurea tolerates standing water indefinitely — but you should still fix the ponding. Standing water on a traffic-bearing deck is a freeze-thaw hazard, an icing hazard, and often a sign of a deflection or slope problem worth investigating. Correct the slope or add drainage; do not use the membrane as an answer to a drainage defect.
Installation, Service & Cost
How long is a deck out of service after coating?
Tack-free in 10–30 seconds and typically open to traffic within the hour. On a parking structure or an operating dock that is the whole reason the system gets chosen — the work can be phased bay by bay or level by level overnight and the area handed back before the next business day, rather than fencing off a level for a week.
What prep does the steel need, and can I overcoat existing rust?
SSPC-SP6 commercial blast to a 2–4 mil angular profile on bare or heavily corroded steel — that produces the 500+ PSI adhesion the load case requires. Sound, tightly-adhered rust can be overcoated after SSPC-SP3 power-tool cleaning with a reduced-warranty note. On marine and de-icing decks, add soluble chloride verification below 7 µg/cm². Loose scale always comes off.
What happens when a section gets damaged?
Repairs integrate rather than patch over. Inside the six-hour recoat window a fresh pass grabs the cured membrane chemically and needs nothing else done to it; past that window, abrade the damaged area and prime it with 7001 first. Either way the repair becomes part of the same monolithic film, so it adds no new seam — a meaningful advantage on a deck where impact damage is routine rather than exceptional.
How does the cost compare to a conventional deck coating system?
Higher material cost per square foot, and lower installed cost on detail-heavy decks once labor is counted honestly. Multi-coat traffic-bearing systems require multiple mobilizations, cure windows between coats, and separate detail work at every joint and drain. This is one mobilization, one material, same-day return to service. Over the service life the comparison is not close — the failure mode a conventional system has at year five is the one this system is specifically engineered against.
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