Car Park Waterproofing Contractors
Deck waterproofing for multi-storey, rooftop, underground and podium car parks — concrete repairs, traffic-bearing membranes, wear courses, joints and drainage, phased so your car park stays open.
Car Park Deck Waterproofing Specialists
A car park deck is a concrete structure that is driven on, rained on and salted every winter. Water on its own is a nuisance — it drips onto cars and stains the soffits below. Water carrying chlorides from road salt is the real problem: it soaks into the concrete cover, reaches the reinforcement and starts the corrosion that ends in cracking, spalling and structural repair. Carbonation does the same job more slowly on soffits, columns and beams.
Car park waterproofing stops that cycle. A traffic-bearing membrane bonded to the deck keeps water and chlorides out of the slab, bridges the cracks that every reinforced concrete deck develops, and carries a hard-wearing, slip-resistant wear course that tyres can turn on. Done properly, it is the cheapest structural maintenance a car park owner will ever buy.
MPS Concrete Solutions waterproofs car park decks as part of a complete repair and protection package: we survey the deck, repair the concrete, deal with joints and drainage, then install the waterproofing system. The waterproofing is only ever as good as the deck under it, so we do not coat over defects. For the wider scope of deck work, see our car park repairs and resurfacing service.
- Sika-approved contractors — manufacturer-backed deck systems.
- 25+ years combined experience in concrete repair and structural waterproofing.
- Phased on live sites — bay by bay or level by level, with the rest of the car park in use.
- Free condition survey and an itemised quotation before any work begins.
Most failed car park coatings we are asked to replace failed at a detail — a joint, an upstand, a drainage outlet — or because they were laid over unrepaired concrete. We survey first and price the repairs, detailing and membrane together.
Waterproofing for Every Part of a Car Park
Different parts of the same car park see different exposure, so they rarely need the same system. A typical multi-storey car park waterproofing specification is split by zone:
Top & Roof Decks
Fully exposed to rain, UV, frost and salt. These need a crack-bridging, UV-stable membrane with a heavy-duty wear course — usually a polyurethane or PMMA deck system — and careful detailing at upstands, outlets and parapets.
Intermediate Decks
Covered, but still wetted by water and slush carried in on vehicles. Salt-laden drips concentrate at entry routes, ramps and turning areas, so protection is targeted where the chlorides arrive.
Ramps & Turning Areas
The highest abrasion on the deck. High-friction, anti-skid wear courses resist tyre scrub and keep vehicles and pedestrians safe in the wet. See our anti-skid surfacing service.
Podium & Underground Car Parks
Where the car park sits over occupied space or below a building, a leak is a building problem, not just a car park one. We waterproof podium decks and below-ground car parks to keep water out of the structure and the spaces beneath.
Expansion Joints
A failed joint lets water bypass the whole deck system onto slab edges and soffits. We break out and rebuild nosings and install traffic-rated joints that move without losing their seal.
Soffits, Columns & Beams
Anti-carbonation coatings protect the underside of decks and the frame from CO₂ and moisture after repairs, slowing the next round of corrosion.
Car Park Deck Waterproofing Systems
A deck waterproofing system is a build-up, not a single coat. The usual sequence is substrate preparation and concrete repair, a primer matched to the deck, the waterproofing membrane — reinforced at cracks, joints and details — and an aggregate-dressed wear course and top coat with line marking. Each layer is applied at the specified thickness and recorded for the guarantee.
Polyurethane Deck Systems
Elastomeric polyurethane membranes with excellent crack-bridging and durability. They are the default choice for exposed top decks and build into full trafficked specifications with wear courses for vehicle and pedestrian use. Cure times are longer, typically 24–48 hours before traffic.
PMMA / MMA Fast-Cure Systems
Methyl methacrylate resins cure in hours, even in cold weather, so a bay can be coated and handed back to traffic the same day. On a live car park where every closed bay costs revenue, the faster programme usually outweighs the higher material cost. Our guide to PMMA vs polyurethane deck coatings compares the two in detail.
Epoxy Screeds & Coatings
Hard-wearing epoxy screeds suit heavily trafficked, covered decks where abrasion resistance matters more than crack-bridging. They are not a substitute for a flexible membrane on an exposed deck.
Standards We Work To
- BS EN 1504-2 — surface protection systems and deck coatings.
- BS EN 1504-3 — repair mortars for spalled decks and soffits.
- IStructE car park recommendations — inspection, maintenance and management of car park structures.
For a fuller comparison of systems, see choosing the right car park deck waterproofing system.
How We Waterproof a Live Car Park
- Condition survey — we map spalling, cracking, delamination, failed joints, ponding and drainage defects, and test where needed, so the specification matches the deck.
- Concrete repairs — unsound concrete is broken out, reinforcement treated and the profile reinstated to BS EN 1504-3. See our concrete spalling repair guide.
- Joints and drainage — expansion joints replaced, outlets and channels repaired, falls corrected where water ponds.
- Preparation — the deck is shot-blasted or ground to a clean, sound, profiled surface.
- Membrane and wear course — primer, membrane, detailing and wear course installed and checked for thickness, then lined and handed back.
Throughout, works are phased by bay, zone or level, with the working area coned off and the rest of the car park in use. At Bromley South Central, a multi-level car park in London, we installed a new expansion joint system and carried out patch repairs while the car park stayed open.
How Much Does Car Park Waterproofing Cost?
The honest answer depends on the deck under the coating. A sound deck that only needs protection is a very different job from one with spalling, failed joints and ponding. As an indication for UK commercial car parks:
| Scope | Indicative cost per m² |
|---|---|
| Deck coating systems | £20 – £50 |
| Full deck resurfacing system | £45 – £90 |
| Including structural repairs, drainage and joint replacement | £80 – £150 |
Prices are indicative, exclude VAT, and depend on deck condition, system, access and phasing. See the full car park waterproofing and resurfacing cost guide for preparation, joint and soffit repair pricing and example project budgets.
Where We Work
We are based in Sandy, Bedfordshire, and waterproof car park decks across the UK. We cover London and the South East, and Bedfordshire, Hertfordshire and Cambridgeshire. We also have regional pages for Birmingham, Manchester, Bristol and 50 UK cities.
Car Park Waterproofing FAQs
Why do car park decks need waterproofing?
Car park decks are exposed to water, road salt and carbon dioxide. Chlorides carried in on tyres and carbonation of the concrete cover both lead to corrosion of the reinforcement, which causes cracking, spalling and, if left, structural repair. A traffic-bearing waterproofing system keeps water and chlorides out of the slab and stops leaks onto vehicles and levels below.
How much does car park waterproofing cost?
As an indication, car park deck coatings cost £20–£50 per m² and full resurfacing systems £45–£90 per m² in the UK. Projects that include structural concrete repairs, drainage and joint replacement typically run £80–£150 per m². Prices exclude VAT and depend on deck condition, system and access — a condition survey is needed for an accurate quote.
Can a multi-storey car park stay open during waterproofing?
Yes. Works are phased by bay, zone or level with the working area coned off and the rest of the car park in use. Fast-cure PMMA systems can return a bay to traffic within hours, which allows overnight and weekend working on live sites.
Which waterproofing system is best for a car park top deck?
Exposed top and roof decks need a UV-stable, crack-bridging membrane with a hard-wearing, slip-resistant wear course — usually a polyurethane or PMMA deck system. Where downtime or cold weather is the constraint, PMMA is normally specified because it cures quickly at low temperatures. Intermediate covered decks often need a lighter build-up. We specify after surveying the deck.
Get a Free Car Park Deck Survey
Tell us about your car park and we'll survey the deck, specify the right waterproofing system and provide an itemised quotation, with a phasing plan that keeps it open.
