How to Waterproof Your Shower: Step-by-Step Guide

Checklist: What You'll Need

Before applying a shower waterproofing membrane, make sure you have the right materials and application tools ready. At Zocoo Australia, we stock a wide range of waterproofing products.

How to Waterproof a Shower

Shower waterproofing needs extra attention around corners, joints, penetrations and the floor waste. This is where movement and gaps commonly create opportunities for water to get through. The key is to prepare the substrate properly, seal the vulnerable areas and apply the membrane according to the product requirements.

1. Prepare the Substrate

Good waterproofing starts with good preparation. Before applying anything, the substrate moisture must be below 8% and ready for the primer. For concrete, cement render and masonry, clean the entire area thoroughly, removing dust, dirt, mould, grease and oil.

Mark the required waterproofing height on the walls and use a level to keep the line consistent around the shower. Mask along the line for a clean finish.

Check the substrate for cracks, holes and gaps around pipes and other penetrations. Repair any defects and allow the repairs to cure before moving on to priming.

2. Prime with PM-21

PM-21 is a two-part epoxy repair primer designed for concrete, cement and mortar. It penetrates porous surfaces to help seal and prepare the substrate before the waterproofing system is applied.

Mix Part A and Part B at a 1:2 ratio by weight. Mix with a slow-speed mixer, or by hand, for at least three minutes until the mix is homogeneous, taking care not to entrain air.

PM-21 has a pot life of approximately 30 minutes, so mix only the amount you can apply within that time. Apply the primer evenly using a brush, roller or electric sprayer. Highly porous surfaces require a second coat. Allow the primer to dry before moving on to the next stage, following the product's technical data sheet.

3. Detail the Joints, Corners and Penetrations

This is the step that decides whether a shower leaks. These areas are more vulnerable to movement and are common points for water to find a way through.

Using the recommended flexible filler product, reinforce joints where required. For example, SH-502 can be used as part of a compatible waterproofing system. Follow the product's mixing ratio, application instructions and working time. Pay particular attention to the wall-to-wall corners, wall-to-floor junction and areas around pipes and the waste.

4. Apply the Recommended Membrane

Once the detailed areas are ready, apply the waterproofing membrane evenly across the walls and floor. Work systematically so the entire required area is covered, including the previously detailed sections.

Avoid relying on appearance alone to judge membrane thickness. Follow the coverage requirements and application instructions on the membrane you select to achieve the specified coating thickness. Apply the second coat only after the first has reached the required recoat stage.

We have a range of membranes listed, including commonly used ones such as, GB-75 and WP-16. Contact us, and we can help you choose the right waterproofing requirements for your project.

5. Inspect Before You Tile

Don't rush into tiling as soon as the membrane looks dry. Inspect the completed waterproofing first, checking the walls, floor, corners, joints and areas around penetrations and the waste.

Look for missed areas, pinholes, thin coverage, damage or other visible defects. Any issues should be addressed before tiling begins. Once the waterproofing has cured and passed the required checks, the shower area can move on to the next stage of the renovation.

Enquire About Waterproofing Your Shower Today

Need help choosing the right waterproofing system for your shower? Contact Zocoo Australia to discuss your substrate, application and waterproofing requirements.

Take the guesswork out of shower waterproofing. Our friendly team can help you understand the options and plan the right approach for your project.