Waterproofing and tiling
Bathroom Waterproofing and Tiling in Hamilton and the Waikato
This is the part of a bathroom renovation nobody sees once it is finished, and the part that decides whether the room lasts fifteen years or fails quietly behind the wall in two. Every full renovation we do includes this work. This page covers what it actually involves, whether you are doing a full renovation or specifically want this work assessed on its own.
The process
How it is actually done
Substrate preparation
Walls and floor are checked and prepared so the membrane has a sound, correctly fixed surface to bond to. This is where old, damp-affected linings from an older Waikato house get found and dealt with before anything else happens.
Membrane application
A waterproofing membrane is applied to the floor and up the walls of the wet area to the height required under Building Code clause E3, with particular attention to junctions, corners and where the floor meets the wall, which is where failures most often start.
Falls and drainage
Floor falls are set so water runs correctly to the waste, checked with a level rather than by eye. This matters even more in a walk-in shower or wet room, where a much larger area of floor needs a consistent, correct fall.
Curing and testing
The membrane is left to cure properly before tiling starts. Rushing this step is one of the most common causes of waterproofing failure in bathroom renovations generally, and it is not something that can be corrected once tiles are down.
Tiling
Tiles are laid to the height and format agreed in your package, with attention to grout line consistency, correct adhesive for a wet area, and sealing of grout in high-moisture zones.
Who needs to think about this specifically
Anyone who has noticed soft or spongy flooring near a shower, a musty smell that will not shift, grout that has gone dark or black no matter how it is cleaned, or a stain on the ceiling in the room below a bathroom. These are usually signs of a waterproofing membrane that has already failed, not a cosmetic tiling issue.
Why it matters more than it looks like it should
- A failed shower waterproofing membrane can send water into wall framing and subfloor for months before it is visible, by which point the repair is far bigger than the original job
- Insurance and future buyers increasingly ask for evidence that wet area work was done to code
- Council inspections, where consent applies, specifically check waterproofing before it is covered by tiles
- Retiling over failed waterproofing does not fix the underlying problem, it just hides it again
What it costs
Where this sits on price
Waterproofing and tiling to the wet area is included in every package, starting with The Refresh, from $18,000. Full height tiling across every wall is an option on The Renovation and included as standard on The Premium, from $42,000. Where a full renovation is not otherwise needed but the waterproofing itself has failed, we quote that work on its own once we have assessed what is behind the existing tiling.
See full package pricingOlder Waikato housing stock
Bathrooms built before modern E3 requirements existed often have thin or missing waterproofing, particularly in Hamilton's 1950s and 60s stock and older Cambridge villas. We treat this as the expected starting condition in these homes rather than an unusual find, which keeps it out of the surprise pile.
Common questions
Waterproofing and tiling questions
Clause E3 is the section of the New Zealand Building Code covering internal moisture, and it sets out how wet areas like bathrooms and showers must be constructed and waterproofed to stop moisture damaging the building. It is the standard we build every wet area to, whether or not your specific job requires council consent.
Get your bathroom assessed properly
Book a free measure up. We will check what is behind your existing tiling where we can, and give you a straight answer on what it needs.