GARAGE WATERPROOFING IN AUCKLAND — HYDREPOXY SLAB & WALL TREATMENT
Auckland garages — especially under-house and partially-subterranean ones on the North Shore — deal with a specific and persistent problem: water pushing up through the slab or tracking in through concrete walls. Because standard paints and sealers simply aren’t built for this, they fail quickly under hydrostatic pressure. The solution is an engineered moisture barrier designed specifically for this environment.
For this reason, we use ARDEX WPM 300 (HydrEpoxy), a two-component water-based epoxy applied directly to your garage’s concrete slab or interior walls. It bonds to damp concrete, resists up to 250 kPa of hydrostatic pressure, and creates a continuous barrier that won’t blister, peel, or crack with normal garage use.
BOOK A FREE GARAGE INSPECTION
Before you spend money on floor coatings, epoxy paint, or drainage fixes, it’s worth finding out exactly where the water is coming from. We offer a free site visit across Auckland to diagnose the source — slab, wall, or perimeter joint — and give you a written quote.
AUCKLAND GARAGE WATER PROBLEMS WE SOLVE
Garages fail differently to other spaces. The issues we’re called in for most often include:
- Rising damp through the slab — moisture vapour pushing up from the subgrade, causing floor coatings to bubble and peel
- Water tracking through garage walls — especially on sloping sites where soil is banked against the exterior
- Efflorescence and salt bloom — white crystalline deposits on walls indicating active moisture movement
- Under-house garages on the North Shore — where cut-and-fill sections leave garage slabs partially or fully below grade
- Damp concrete before floor coatings — HydrEpoxy provides the moisture barrier required before epoxy floor coatings or tiles
WHY HYDREPOXY WORKS FOR GARAGES
Most garage waterproofing products target above-grade surfaces. HydrEpoxy, however, carries a specific rating for negative-side (interior) application against hydrostatic pressure — meaning it works even when water is actively pushing from outside.
Key reasons we recommend it for garage applications:
- Adheres to damp or green concrete — no need to wait for the substrate to dry out completely
- 250 kPa hydrostatic pressure rating — handles the pressure from saturated soil on sloped sites
- No excavation required — applied to the interior face of walls or directly to the slab
- Compatible with floor coatings and tiles — wait 24 hours for tiling; 7 days for full cure before applying floor systems
- Water-based formulation — low odour, suitable for enclosed garage spaces
Is your garage partly below ground? HydrEpoxy is the right product. If you have a dedicated below-ground living space or wine cellar, see our Basement Waterproofing page instead.
OUR GARAGE WATERPROOFING PROCESS
We follow a consistent, documented process on every Auckland garage job:
- Free site visit — we assess slab moisture levels, wall condition, and the likely source of ingress
- Written quote — itemised and fixed-price so there are no surprises
- Substrate preparation — we mechanically remove all existing coatings, paint, sealers, and surface contaminants to ensure the best possible adhesion. This is a step we never cut corners on, because proper prep is the foundation of a long-lasting result. For minor grinding work, we take care of it as part of our service. If the scope of grinding goes beyond what we handle, we’ll point you in the right direction — recommending a qualified building practitioner so you can get that sorted before we step in to apply the waterproofing.
- HydrEpoxy application — we apply two full coats of HydrEpoxy by roller to your walls and/or slab, ensuring thorough, even coverage throughout. To give your waterproofing system extra strength and longevity, we reinforce all corners, joints, small cracks, and transitions with either Deckweb or fibreglass mesh — the areas most vulnerable to movement and moisture entry.
- 7-day cure — minimum cure period before installing floor coatings, wall linings, or tiling
- PS3 producer statement — available on request for building consent purposes
In addition, we are Ardex Certified LBP installers, meaning your job is done to specification with full product warranty support.
WHAT GARAGE WATERPROOFING COSTS IN AUCKLAND (2026)
Pricing is based on the total surface area treated and site complexity.
| Job Type | Indicative Price (excl. GST) |
|---|---|
| Small garage wall section (≤ 6 m²) | From $990 |
| Single garage floor slab (approx. 20 m²) | From $2,200 |
| Under-house garage — walls + slab combined | From $2,400 |
| Retaining wall interior (per lineal metre) | From $110/lm |
All prices are indicative. However, we provide a written fixed-price quote after the site visit, and most Auckland garage jobs are quoted within 24 hours.
AREAS WE COVER
We waterproof garages across Auckland, including:
- North Shore: Takapuna, Devonport, Birkenhead, Northcote, Glenfield, Albany, Silverdale
- Central Auckland: Ponsonby, Grey Lynn, Mount Eden, Remuera, Epsom
- West Auckland: Henderson, New Lynn, Titirangi
- East Auckland: Howick, Pakuranga, Botany
On-slope and under-house garages on the North Shore are our most common call-out for this system.
FAQs – GARAGE WATERPROOFING WITH HYDREPOXY
No. All existing coatings must be mechanically removed before application. Adhesion depends on direct contact with bare concrete.
HydrEpoxy stops liquid water and vapour pressure from the substrate. General condensation caused by temperature difference (not ground moisture) may need additional ventilation. We’ll advise during the site visit.
Yes — wait a minimum of 24 hours before tiling. Use an appropriate tile adhesive and grout rated for wet areas.
Not always, but we can provide one if required by your council or building consent. Ask us at quote stage.
No. We work around existing drains and can treat up to the drain surround. We’ll assess this on-site.
Your waterproofing is backed by a 10-year ARDEX product guarantee on materials from the date of purchase, along with our own 5-year workmanship warranty — so you can have complete peace of mind that the job is built to last.