The Complete Guide To Waterproofing Wet Areas

Showers, Baths, Splashbacks, Vanities & Laundries (Australian Guide)

If you’ve ever searched:

  • How to waterproof a shower properly

  • Why is my bathroom leaking?

  • How often should you reseal a shower?

  • Best sealant for bathroom wet areas

This guide is for you.

Wet areas are where most DIY disasters start. Water doesn’t need a big gap. It needs a pinhole. Once it gets behind tiles or cabinetry, the damage is slow, expensive and usually invisible until it’s serious.

This is the complete guide to waterproofing wet areas properly, and knowing when it’s time to reseal.

What Is A “Wet Area” In A Home?

In Australian homes, wet areas typically include:

  • Showers

  • Baths

  • Kitchen splashbacks

  • Vanities

  • Laundry tubs

Anywhere water is regularly splashed, sprayed or pooled needs proper sealing.

It’s not just about waterproof membranes under tiles. It’s also about the visible sealant joints that stop water getting behind surfaces.

How To Waterproof A Shower Properly

The shower is the highest-risk wet area in the house.

The key waterproofing points are:

  • Wall-to-wall corners

  • Wall-to-floor junction

  • Around shower base

  • Around shower screen frame

Best Sealant For Showers

Use a mould resistant bathroom silicone. It must be:

  • Waterproof

  • Flexible

  • Designed for wet areas

Acrylic sealant is not suitable for showers. It will fail.

Common Shower Failure Points

  • Silicone peeling away from tiles

  • Gaps forming in corners

  • Mould growing under the sealant

  • Cracked grout lines

If silicone is lifting, cracked or mouldy beyond cleaning. It’s time to reseal.

How To Seal Around A Bath

The joint between a bath and the wall is a major leak zone.

Why? Because baths flex when filled.

When a bath fills with water and someone sits in it, it drops slightly. When drained, it rises again. That movement stresses the seal.

How To Seal A Bath Properly

  • Use mould resistant silicone

  • Tool it properly for full contact

Signs Your Bath Needs Resealing

  • Silicone separating from one side

  • Persistent mould at the joint

Waterproofing Kitchen Splashbacks

Kitchen splashbacks aren’t submerged like showers, but they cop constant splashes, especially around sinks.

Key sealing point:

  • Between benchtop and tiles

Use silicone where water exposure is frequent.

Acrylic can be used in dry decorative areas, but anywhere near a sink should be silicone.

Common Splashback Failures

  • Gaps forming along benchtop edge

  • Water swelling particleboard cabinets

  • Mould forming behind sink

Water damage around kitchen cabinetry often starts with failed splashback sealant.

Sealing Around Vanities

Vanities sit right in the splash zone.

Important joints:

  • Between basin and benchtop

  • Between benchtop and wall

  • Around tap penetrations

If water gets behind the vanity, it often causes:

  • Swollen cabinetry

  • Delaminating panels

  • Musty smells

Use bathroom-grade silicone in all exposed joints.

Waterproofing Laundry Tubs

Laundry tubs are often overlooked.

But they deal with:

  • Heavy splashing

  • Detergents

  • Hot and cold temperature swings

Seal:

  • Around the tub perimeter

  • Splashback junction

  • Tap penetrations

Again, silicone is the correct product for waterproof sealing.

Common Wet Area Failure Points

Across all wet areas, failures usually happen at:

  • Wall-to-floor junctions

  • Internal corners

  • Around penetrations (taps, shower screens)

  • Where different materials meet

Movement and water are the two enemies.

Tiles expand. Timber moves. Metal flexes. Silicone must stretch with them.

If a low-flexibility sealant is used, cracking is inevitable.

How To Tell When It’s Time To Reseal

Many people search “how often should you reseal a shower?”

There’s no fixed timeframe. It depends on usage and installation quality.

But here are clear signs you need to reseal:

  • Silicone is cracked or splitting

  • Sealant has pulled away from one side

  • Black mould embedded inside the silicone

  • Silicone feels hard and brittle

  • Water is getting behind tiles

If mould won’t clean off and looks like it’s inside the sealant, it’s usually time to remove and replace it.

In high-use family bathrooms, resealing every 3-4 years isn’t uncommon.

What Causes Wet Area Sealant To Fail?

In Australian homes, common causes include:

  • Poor surface preparation

  • Applying silicone over old silicone

  • Using acrylic in wet areas

  • Not allowing proper cure time

  • Excessive movement

Heat and humidity cycles also stress sealants over time.

How To Prevent Water Damage In Wet Areas

The key rules:

  1. Use mould resistant bathroom silicone

  2. Never use acrylic in showers

  3. Remove old sealant completely before resealing

  4. Ensure surfaces are clean and dry

  5. Allow full curing before exposing to water

Skipping any of these increases failure risk.

Final Word: Waterproofing Is About Prevention

Water damage in bathrooms and laundries rarely starts with a burst pipe.

It starts with a 2mm gap that no one noticed.

Sealing wet areas properly isn’t about aesthetics. It’s about protecting:

  • Subflooring

  • Wall framing

  • Cabinetry

  • Structural integrity

If you treat wet area sealing seriously, you avoid expensive repairs later.