Bathroom Wet Areas We Waterproof
A bathroom has multiple wet zones — and each one needs the right level of protection to keep moisture where it belongs. Our certified waterproofers cover every water-exposed surface in your bathroom to AS 3740 standards, giving you complete coverage from floor to wall and every junction in between.
Shower areas are waterproofed to a minimum 1800mm wall height, with full floor coverage and 150mm beyond the shower opening. Bathroom floors receive full surface waterproofing with a membrane turned up 100-150mm at every wall edge. Behind the bath gets full waterproofing of the surround and substrate — a zone that’s regularly missed and regularly fails. Vanity splash zones and floor areas around the basin cabinet are covered, as is the toilet base perimeter where floor moisture consistently builds up. Every corner and wall-to-floor junction throughout the bathroom gets detail bands and full junction sealing applied — because that’s where most waterproofing failures start.
Shower Waterproofing Methods We Use
Liquid Membrane Application for Standard Showers
Liquid membrane is our go-to method for most shower waterproofing jobs across Lake Macquarie. We paint it directly onto the substrate in multiple coats — base coat first, detail bands at all corners and junctions, then second and third coats across critical areas. Once cured, it becomes a fully flexible, seamless barrier that moves with the building and withstands the constant moisture load a shower produces daily.
Sheet Membrane for Heavy Duty Waterproofing
Sheet membrane systems use pre-formed sheets bonded directly to the substrate and sealed at every seam. Where liquid membrane suits most residential showers, sheet systems deliver a heavier-duty solution for high-use or large-format showers where extra durability is the priority. Every seam and junction gets sealed to the same AS 3740 standard, giving you a robust waterproofing layer that handles the demands of heavy daily use without compromise.
Combined Systems for Maximum Protection
Combined systems pair a sheet membrane across the shower floor with a liquid membrane up the walls — leveraging the strengths of both methods where each performs best. The floor gets the heavy-duty sheet base handling constant water pooling and drain movement, while the walls get the seamless flexibility of a liquid system. For homeowners wanting the highest level of protection, this is the premium option.
Bathroom Floor Waterproofing Lake Macquarie
The bathroom floor is the highest-risk surface in any wet area — it collects water from every direction, sits beneath every fixture, and connects to every wall junction in the room. In Lake Macquarie’s coastal climate, where humidity stays elevated year-round, and moisture has more opportunity to work into substrates, getting bathroom floor waterproofing right isn’t something you cut corners on.
Full AS 3740-compliant bathroom floor waterproofing means complete surface coverage across the entire floor area — not just around the shower base or under the drain. Membrane is applied across the full floor surface and turned up a minimum of 100-150mm at every wall edge, around the toilet base perimeter, and beneath the vanity cabinet footprint. Every floor-to-wall junction gets detail bandaging applied before the membrane goes on — because that’s the line where water pressure is highest, and failures happen first.
Our certified waterproofers assess the substrate condition and floor falls before a drop of membrane goes down, making sure your bathroom floor is properly prepared, fully covered, and built to last in Lake Macquarie’s environment.
Shower Waterproofing for Bathroom Renovations
When you’re renovating a bathroom in Lake Macquarie, shower waterproofing isn’t something you schedule after everything else is sorted — it’s the step that everything else depends on. Tiles, fixtures, screens, and finishes all go on top of the waterproofing membrane, which means if the membrane isn’t right, nothing that comes after it is protected either.
During a bathroom renovation, waterproofing happens at the right point in the build sequence — after the substrate is prepared and any plumbing rough-in is complete, but before a single tile goes down. This is when conditions are optimal, the substrate is fully accessible, and detail bands can be properly installed at every corner, junction, and penetration. Trying to cut costs or compress the timeline by rushing through waterproofing at this stage is where most renovation leaks originate.
We work alongside bathroom renovation projects across Lake Macquarie, coordinating waterproofing installation, flood testing, and AS 3740 certification so tiling can proceed on schedule without handover issues between trades.
Behind the Bath — Why It Can’t Be Skipped
The area behind and beneath your bath is one of the most consistently under-waterproofed zones in Lake Macquarie bathrooms — and one of the most expensive to fix when it fails. Water gets in through the bath rim, the tap penetrations, and the overflow fitting. From there, it sits against the substrate, works into the wall framing, and starts breaking down everything it touches. By the time you notice it, the damage is already done.
Proper waterproofing behind the bath means full membrane coverage across the bath surround, substrate, and every penetration point before anything else goes on top. That’s what AS 3740 requires — and what our certified waterproofers deliver on every bathroom we work on.
What failing bath waterproofing leads to:
- Rotted wall framing and floor joists directly behind the bath structure
- Mould growth inside wall cavities that’s invisible until walls are opened
- Subfloor damage from water pooling beneath the bath base
- Ceiling damage in the room below from long-term moisture penetration
Don’t skip it. Don’t let your tiler skip it either.
Our Bathroom Waterproofing Process
| Assessment & Preparation | Membrane Installation | Testing & Certification |
|---|---|---|
| Every bathroom waterproofing job starts with a thorough on-site assessment of every wet zone — shower, floor, bath surround, vanity, and all wall junctions. We check substrate condition, floor falls, drainage, and any existing waterproofing that needs stripping back. Surfaces are cleaned, repaired where needed, and primed correctly before a single drop of membrane goes down. | With preparation complete, we apply a quality membrane system across every wet zone to full AS 3740 coverage requirements. Detail bandaging goes on at every wall-to-floor junction, corner, and penetration point first — then full membrane coats are applied across shower walls, bathroom floors, bath surrounds, and all fixture perimeters. Every coat is allowed proper cure time before the next layer goes down. | Once membrane installation is complete, flood testing is carried out where required, and a full visual inspection confirms coverage across every surface. We provide a compliance certificate on completion documenting that your bathroom waterproofing meets AS 3740 standards — the paperwork your renovation, your council, and your insurer may require before tiling and finishing work begins. |
Bathroom Waterproofing FAQs
AS 3740 is the Australian Standard for waterproofing domestic wet areas. It sets legal minimum requirements for membrane coverage, wall heights, junction treatment, and flood testing. Any shower that doesn’t meet AS 3740 is non-compliant and puts your home’s structure and insurance at risk.
Most shower waterproofing jobs take two to three days from substrate preparation through to flood test completion and certification. Remedial jobs on leaking showers can take longer, depending on substrate damage found once tiles are removed and assessed.
Yes, every shower we waterproof gets flood tested before tiling begins. The shower base is filled with water and held for 24 hours. Results are documented and a compliance certificate is issued only after the flood test passes.
No. Applying a membrane over existing tiles doesn’t meet AS 3740 and won’t provide lasting protection. All tiles and existing waterproofing must be stripped back to bare substrate before a compliant membrane system can be properly installed and certified.
Most leaking showers in Lake Macquarie come down to failed or inadequate original waterproofing — particularly in homes built before current AS 3740 standards. Coastal humidity, salt air, and age accelerate membrane breakdown, while poor original installation is the most common cause.
Get Your Bathroom Waterproofed by Lake Macquarie’s Certified Specialists
Proper wet area waterproofing in Lake Macquarie starts with a thorough assessment of every wet zone in your bathroom — shower, floor, bath surround, vanity, and every junction in between. Our certified waterproofers deliver full AS 3740-compliant coverage, quality membrane systems, and the compliance certificate your renovation requires on completion.
Whether you’re mid-renovation and need waterproofing before tiles go down, or you’re dealing with signs of failed waterproofing in an existing bathroom, we’re ready to help. Call us today to book your bathroom waterproofing assessment or request a quote online. One call gets you a certified waterproofer on-site, a clear scope of work, and a bathroom that’s built to handle everything Lake Macquarie’s coastal environment delivers.
