Parkade waterproofing

The membrane is the only thing between your slab and the rain.

Traffic-bearing systems for suspended slabs, ramps and exposed roof decks — installed in phases so the building keeps working while we do.

Request a site assessment Call (236) 873-2580

The work

How a parkade waterproofing system works

A parkade membrane is not paint. It is a built-up system, specified layer by layer to the deck’s condition, exposure and traffic — sometimes two coats, sometimes four or more, depending on the system. A primer bonds to the concrete and tolerates vapour coming up out of it. The waterproofing membrane bridges cracks as the slab moves. Where slip resistance is required, an aggregate broadcast carries the abrasion. Where ultraviolet exposure calls for it, an aliphatic wear coat takes the sunlight so the layers beneath it never see sun.

Get one of those wrong and the system fails in a predictable way. Skip the moisture test and it blisters. Under-broadcast the aggregate and the membrane becomes the wearing surface and wears through in a couple of winters. Use an aromatic topcoat on an exposed roof deck and it ambers and chalks through the first Whistler summer.

Vertical detailing is where most systems are actually lost. The membrane has to turn up at every curb, column, wall junction and drain, and it has to be terminated properly at every expansion joint. Water does not care that ninety-eight per cent of your deck is perfect.

Build: Primer, membrane, broadcast, wear coat
Return to traffic: By phase, once cure is confirmed on site
Systems: Vulkem EWS, Sika and MasterSeal traffic systems
Assessment: Sounding, moisture test, drains, joints

Detail

Phasing is the part that decides whether a project is tolerable.

Nobody can close a residential parkade for three weeks. The scope we write starts from how many stalls you can afford to lose at once and works backwards — commonly quarter-level phases, sometimes single bays, sometimes night work on ramps and entrances where daytime closure is impossible.

Each phase goes back into service once the manufacturer's cure for the specified system is confirmed on site, and that time depends on the system and on the weather: a polyurethane membrane in a cold, damp February parkade is not ready when the datasheet's laboratory figure says it is. Ask any contractor you compare us against for the return-to-traffic time for the system they have actually specified, in the season they will install it.

From the field

Traffic coating in a Canadian Tire mechanical room.

A mechanical room takes the same punishment as a parkade deck in a smaller space: pumps, boilers and switchgear on housekeeping pads, pipe penetrations everywhere, and water that has to be kept off the slab and away from whatever sits below. This Canadian Tire mechanical room received a broadcast-textured traffic coating across the whole floor, carried up onto the equipment plinths and terminated at the wall bases and around every penetration, with the plant left in place throughout.

Finished grey traffic coating across a Canadian Tire mechanical room floor, running between equipment plinths, switchgear and a base-mounted pump — The whole floor, with the coating carried up onto the pump plinth and the equipment pads.

Close view of the broadcast-textured traffic coating in the Canadian Tire mechanical room, terminated around pipe supports and up the face of a plinth — Close up: the aggregate broadcast for grip, and the terminations at pipe supports and plinths.

Canadian Tire — mechanical room traffic coating. Our own work, our own photographs.

Two of our documented parkade projects show how the phasing works at scale. On the Sutton Place Hotel ramp in Downtown Vancouver, 8,400 ft² where valet access could not close during the day, we worked overnight on half the ramp width at a time and handed the full ramp back in service every morning. On a four-level, 50,000 ft² commercial parkade in Burnaby the work ran in four phases and the structure was never fully closed. Both are written up on our projects page.

Detail

Why Greater Vancouver decks fail faster than the datasheet suggests.

Chlorides are the accelerant. Road salt tracked in off the North Shore and the Sea-to-Sky in winter dissolves in standing water, works down any crack it finds, and depassivates the reinforcing steel. Once the steel starts corroding it expands, and expanding steel inside concrete has nowhere to go but out.

Richmond adds a second mechanism. A high water table means vapour drive up through the slab is constant, so a system that would be fine in a dry climate blisters from underneath. Whistler adds a third: eighty-plus freeze–thaw cycles a season, which means the membrane has to stay flexible at temperatures where cheaper products go brittle.

Scope

Suspended or on-grade decides what the deck actually needs.

A waterproofing membrane exists to protect whatever is underneath the slab. A suspended slab, a ramp over occupied space or an exposed roof deck needs one. A slab-on-grade level has nothing beneath it but earth, so it does not need a membrane at all; what it needs is a wear coating that stands up to salt, oil and tyre abrasion and does not trap moisture rising through the slab. Many parkades are both, on-grade at the bottom and suspended above, and a scope that does not say which system goes on which level is a scope that has not been thought through. The difference is set out in our guide to traffic membranes versus epoxy on suspended slabs.

The second decision is repair, recoat or replace. If the existing membrane is bonded and intact and only the wear coat has worn through, a recoat of the wear course restores the system for a fraction of the cost of replacement. If the membrane is debonded, blistered or cracked, or it is failing at the upturns and joints, patching buys a season and no more, and replacement is the honest recommendation. If the concrete itself is spalling or delaminated, that is structural repair and it comes before any membrane. The assessment tells us which of the three you are looking at, and we quote each separately so the council can see what is waterproofing and what is repair.

Questions we get

Straight answers.

How long does a parkade membrane last?

A correctly specified and correctly installed traffic deck system should give you ten to fifteen years on a suspended slab, and often longer on a deck that is not exposed to direct sun. The variables that move that number most are the quality of the surface preparation, whether the drainage actually works, and whether the wear coat gets refreshed once during the system's life.

Can you work while the parkade stays open?

Yes, and on occupied buildings that is almost always how we do it. We phase the work by level or by bay so residents and tenants keep access throughout, and we work nights on ramps and entrances where a daytime closure would not be workable.

Do we need to fix the concrete first?

If there is spalling, delamination or exposed rebar, yes — a membrane over failing concrete just hides the problem while it gets worse underneath. We sound the deck during the assessment and quote any structural repair separately so you can see what is waterproofing and what is repair.

What does the assessment involve?

A walk of the deck, sounding for delamination, moisture testing of the slab, a look at the drains and the expansion joints, and photographs. From that we can tell you what the deck needs, what it will cost, and how it can be phased.

Is this covered by our strata's depreciation report?

Parkade membrane replacement is normally a line item in a depreciation report, and if yours is coming due it is worth pulling that section before we visit. We can write the scope to match how the report described it, which tends to make the approval conversation much shorter.