Wet areas are among the most high-risk zones for building defects. A failed waterproofing system can lead to persistent leaks, structural deterioration, mould growth, and expensive litigation. Most failures stem from improper detailing, non-compliant installation, or substandard materials — all of which Atomic Projects identifies and rectifies at the source.
1. Diagnostic Assessment
We begin every wet area defect engagement with a systematic assessment:
- Visual inspection for cracked grout, efflorescence, damp patches, or lifting tiles.
- Moisture metre scanning of adjacent substrates, walls, and ceilings below.
- Flood testing (where safe and practical) to confirm waterproofing membrane integrity.
- Review of original waterproofing documentation (if available) to identify specification shortfalls.
2. Failure Classification
Wet area defects typically fall into three categories:
- Sealant-only failure: Cracked or missing sealant at junctions. Addressable without full tile removal if the membrane is intact.
- Membrane failure: Failed or absent waterproofing membrane. Requires tile and screed removal to access and reinstate.
- Substrate damage: Water has compromised the substrate (rot, spalling, delamination). Requires additional make-good before membrane reinstatement.
3. Reinstatement Works
Our reinstatement methodology follows AS 3740 (Waterproofing of Domestic Wet Areas) and NCC requirements:
- Full demolition of affected finishes to expose the substrate.
- Make-good of damaged substrate to a sound, level surface.
- Two-coat liquid-applied membrane system applied to code-minimum thickness, with upstands and junction details.
- Flood test before tiling, with photographic evidence retained.
- Tile reinstatement with matching materials where possible, or agreed alternatives where original tiles are discontinued.
4. Documentation & Sign-Off
Works are completed with a full QA package: flood test records, membrane product data sheets, photographic evidence of each installation stage, and a completion report suitable for submission to NCAT, insurers, or building consultants.
Atomic Projects’ wet area defect repair service is backed by our Class 2 Registered Builder licence and specialist waterproofing expertise — giving building owners and strata managers the confidence that repairs are permanent, compliant, and documented.
Frequently Asked Questions
How do you identify whether a wet area waterproofing system has failed?
We use a combination of visual inspection, moisture metre scanning, and flood testing to assess waterproofing integrity. Signs of failure include efflorescence (white salt deposits), damp patches on ceilings below, discolouration at grout lines, and lifting tiles. In some cases, a flood test is the only definitive method — particularly where the failure is in the membrane itself rather than visible grout or sealant.
Does the entire bathroom need to be stripped to fix a waterproofing failure?
Not always — but it depends on the failure type and location. Failed sealants at junctions can sometimes be addressed with targeted removal. Failed membranes beneath tiles, however, require tile and screed removal to access and reinstate the membrane. We assess each case individually and explain your options, including the risk of recurrence if a non-invasive approach is chosen.
What waterproofing systems do you use for wet area reinstatement?
We typically install AS 3740-compliant two-coat liquid-applied membrane systems (acrylic, polyurethane, or epoxy depending on substrate and exposure conditions) at code-minimum thicknesses — with additional thickness at floor-wall junctions and penetrations. All membranes are flood-tested before tiling commences, with photographic records kept.
What are the NCC requirements for waterproofing in wet areas?
NCC Volume 1 (for Class 2–9 buildings) requires waterproofing in shower recesses, baths, toilets, and laundries. AS 3740 sets the technical requirements for membrane installation, junction details, and bond-breaking. In strata buildings, non-compliance with these standards constitutes a reportable defect under the Design and Building Practitioners Act 2020.
How do you match tiles and finishes after repairs?
Where original tiles are available (from on-site spares or the same batch), we can achieve an exact match. Where tiles have been discontinued, we work with tile suppliers to find the closest available match and discuss options with you — including extending the repair area to a natural break point to minimise visible variation. We never proceed with a finish mismatch without your agreement.
Related Services
Ready to address defects in your building? Atomic Projects is a Class 2 Registered Builder with over 10 years of specialist experience in remedial and defect rectification works across Sydney. Contact our team to discuss your project and arrange a site inspection.
