Make the waterproofing scope clear before the tiles go down.
Bathroom waterproofing should be planned as a complete system, with preparation, application and documentation agreed before tiling.
Compare the Sydney cost planning guide, try the bathroom budget calculator and check illustrated bathroom styles as you shape your brief.
Ask the installer to identify the substrate condition, the proposed membrane system and how junctions, penetrations and drainage will be detailed.
The design needs to suit the room and the applicable building requirements.
Product instructions govern preparation, application conditions and drying stages for the selected system.
Ask the installer to use current manufacturer documentation when scheduling the work.
Request the relevant licence details, records of the work and the written product and workmanship warranty terms.
Keep those documents with the renovation contract and product information.
What to discuss in your brief
- A documented waterproofing scope
- Preparation suited to the existing surfaces
- A build sequence that allows the specified drying stages
- Clear records to keep at handover
Build a clear scope of work
- Arrange an assessment of the substrate and wet areas
- Name the proposed compatible waterproofing system in the quote
- Confirm installer responsibilities and required inspections
- Request the applicable records and written warranty terms
Illustrative design, rather than a completed customer project.
Budget and timing
The planning allowance for this type of scope is $2,000 to $6,000.
Illustrative planning allowances in AUD, not measured market prices or a quote.
Confirm the scope, GST and actual price with the contractor.
Ask the renovator to price access, preparation, product selections and any specialist work for your property.
The indicative work window is 2 to 7 days, with design, approvals and ordering considered separately.
Illustrative construction allowance only.
Design, approvals, product supply and site conditions can change the programme.
Questions about waterproofing
Can waterproofing be priced before the room is stripped?
An initial allowance may be possible, with assumptions about the existing surfaces.
Ask how preparation discovered during removal will be assessed and authorised.
How long does waterproofing need to dry?
Timing depends on the selected system, site conditions and application stage.
The installer should use the current manufacturer's instructions rather than a generic drying time.
Does waterproofing come with a fixed warranty period?
Ask for the actual written terms for the product and the workmanship.
Coverage, conditions and responsibilities vary, so the quote should identify them.
How does the quote referral work?
I pass your project details to a local renovator who can discuss the work and arrange a quote.
The contractor confirms availability, scope, price and terms directly with you.
Checks before work begins
Use the Service NSW licence checker and ask the contractor to explain which licences and insurance apply to the work.
For a strata property, review the NSW renovation approval guidance with your strata manager.
Further reading
- Check a NSW builder or tradesperson licence
- Example manufacturer system guidance: ARDEX WPM 155 Rapid Plus
