AWC — Waterproofing in Boronia

Waterproofing a standard shower costs $300–$600. A full bathroom including shower, floor, and bath area costs $500–$1,200. Balcony waterproofing costs $80–$150/m². These are labour costs only — materials add $50–$200 depending on the membrane system used.

Yes — AS 3740 (Waterproofing of domestic wet areas) is mandatory under the National Construction Code. All showers, bath surrounds, laundries, and balconies must be waterproofed to this standard. Failure to comply can void home insurance claims related to water damage.

A quality waterproofing membrane correctly installed should last 10–15 years minimum. Cheap products or incorrect installation fail much sooner. The grout and tile system on top doesn't waterproof the shower — the membrane underneath does. Grout cracks don't mean the waterproofing has failed.

Signs include damp patches on adjacent walls or floors, mould behind tiles, peeling paint, efflorescence (white mineral deposits), soft or spongy tiles, or a musty smell. A licensed waterproofer can perform a flood test to confirm leakage before expensive rectification work begins.

Generally not recommended for showers. If the existing tiles are sound and firmly bonded, a liquid membrane can be applied over them in some scenarios. However, if there are any cracked, hollow, or loose tiles, these must be removed and the substrate repaired before new waterproofing is applied.