How Bathroom Waterproofing is Done

Bathroom waterproofing is so important, it is mandated by law and must comply with National Building Code Australia (NBCA) and Australian Standards. The basic requirements are that:

• Shower enclosure floors must be thoroughly waterproofed.
• Shower enclosure walls should be waterproofed to 1.8 metres.
• Bathroom walls should be waterproofed to a height of 150mm.
• If the bathroom floor contains or is made of timber or is on the 2nd floor or higher, it must be thoroughly waterproofed.
• The area over the shower enclosure step and down to the floor must be waterproofed.

The waterproofing process is carried out in two stages. First, a coat of sealant is applied horizonally. When this coat cures, the waterproofer returns and applies a second coat vertically to ensure a tight seal.

Bathroom waterproofing is done before tiles are laid. In many cases, your bathroom renovator or tiler will include waterproofing in their quote. If waterproofing is part of their service, make sure they hold a valid waterproofer’s license if needed and issue a certificate of compliance upon completion of the job.

As a rule, professional waterproofing costs around $500 to $650 for an average bathroom. If the waterproofing is done in more than one bathroom or as part of a complete bathroom renovation, the cost may be a little lower. In some cases, such as large bathrooms, wet rooms or second storey bathrooms, the cost of waterproofing may be higher. To get the best price and the best service, get competitive quotes from several services and ask each of them to provide you with all the details about the scope of their service in their quotes.

*Cost and prices in this article are indicative and should only be used as a guide. They also vary locally and are subject to market forces.