A new waterproofing licence is coming for internal wet areas

Internal waterproofing is heading into the Licensed Building Practitioner scheme.

The Government is progressing work to establish a new LBP waterproofing class, putting wet-area work under the same licensing and accountability regime that already covers carpentry, roofing, brick and blocklaying and external plastering. As at September 2026, the new class is not in force.

The Government confirmed the direction in April 2025, listing three changes affecting LBPs, with changes intended to take effect in 2026.

The Registrar gains the ability to triage complaints and appoint investigators. Details of LBPs suspended for disciplinary reasons will be published. And work is being progressed on a new waterproofing licence class so that, in the Government’s words, consumers can be confident those completing wet-area bathrooms and level-entry showers are suitably qualified and accountable for their work.

Wet areas earn that attention. A failure at a substrate junction, a membrane upstand or a shower tray is invisible until it isn’t, and the remediation bill can far exceed the cost to install.

During consultation, MBIE proposed creating an Internal Waterproofing licence class and expanding the definition of restricted building work to include the application of internal waterproofing.

If that approach is adopted, internal waterproofing could only be carried out, or supervised, by an LBP holding the appropriate licence class. The proposal received support during consultation, with 261 of 329 submissions agreeing with the internal waterproofing proposal.

Plenty is still unsettled. The final scope, competency requirements and transition arrangements have not been confirmed, and Building Performance still lists seven LBP licence classes, with waterproofing not among them.

If internal waterproofing is added to restricted building work, the existing documentation requirements would also apply.

Restricted building work already requires the LBP who carried out or supervised it to provide a Record of Building Work to the owner and territorial authority. That would put a named practitioner against the work and create a formal record of who carried it out or supervised it.

The practical impact is likely to be felt most directly by businesses applying internal waterproofing systems, but the eventual scope will determine how far the changes extend into tiling, shower installation, bathroom flooring, vinyl work and other trades.

Builders, plumbers, designers and architects will feel it where they coordinate bathrooms, laundries or level-entry showers, because the licensing question moves upstream into who gets booked and when.

A new waterproofing licence class would require practitioners to demonstrate the necessary competence, as existing LBP licence classes do, and keep those skills current.

Good photographic records will also be worth keeping, a habit worth having for a trade whose work disappears under tile within days. LBPs are already assessed before getting a licence and must keep their knowledge up to date.

For main contractors, the practical change starts at programming rather than at sign-off.

Knowing early who is applying the membrane, whether they will hold the required licence or be properly supervised, and how the work will be documented before it gets covered, is the difference between a clean handover and a scramble at code compliance stage.

There is a supervision question sitting underneath all of this. The scheme allows licensed practitioners to supervise non-LBPs undertaking restricted building work, but the supervisor must hold the appropriate licence for the work being supervised.

If internal waterproofing becomes its own restricted class, a carpentry LBP would not automatically be able to supervise or sign off the membrane simply because they hold a carpentry licence.

None of that needs to wait for the regulations. The paperwork habits are worth building now.

Keep clear records of the product system used and its specification, training completed, supplier accreditations held, substrate preparation, application detail, site photographs at each stage, inspections and sign-offs.

Those records may not all form part of the eventual licence application requirements, which have not yet been confirmed, but they give businesses a much stronger evidence trail than trying to reconstruct past jobs from memory.

Further detail will be published by Building Performance, and the announcements worth watching are the final scope and transition arrangements.

Those details will decide how a small tiling or membrane business moves into the new regime, and they have yet to be nailed down.