How to add waterproofing to new bathroom?

[sachinriz]

Hi Team,

I'm looking to do bathroom waterproofing myself using the right products. I've seen few bunnings videos and others on steps to do. However, need some additional info to clear some questions

my current floor is compressed cement sheet flooring with shower wall on Villaboard.  I can see gaps on edges which i need to seal.here is what i planned to do

1. Seal the gaps and edges with Selley's bathroom silicon or something else?

2. Apply primer on floor and shower walls and 150mm down edges (please recommend primer product to buy)

3. Apply waterproofing membrane (polyurethane is better or something else please suggest product to use) - Coat 1

4. Get screeding done by tiler and apply 2nd coat of membrane ? complete paint on shower 3 walls and 150mm height along the edges. 

5. should i apply bond breaker tape or fabric before 2nd coat?

Appreciate bunnings team advice here

Thanks

Rizwan

[EricL]

Hello @sachinriz 

Thank you for sharing your question about waterproofing. Before you begin, I suggest checking the rules and regulations of your local council about waterproofing your bathroom. They sometimes require a trained professional Waterproofer to seal your shower. 

In regards to your questions:

• Yes, you can use Selleys silicone as long as it is rated for use in wet areas.
   
• I suggest having a look at Dunlop 1L Primer and Additive
   
• There are a few choices for waterproofing. What's important is that you use only one brand and not mix it with other products. 
   
• Screeding is done before waterproofing. Follow the instructions for overpainting distance.
   
• Bond breaker is applied after the first coat. The second coat goes over the bond breaker.

Please make sure to wear personal protection such as gloves, goggles and a paint mask while working on your bathroom.

If you need further assistance, please let us know.

Eric

[sachinriz]

Hi Eric,

Thanks for the suggestions.

I have cemented sheet placed now on bathroom and there are few gaps which I wish to close with silicon and then apply primer and one coat of waterproof membrane before I do the screeding and second coat with bond breaker after screeding . Is this recommended ? or I only fill the gaps with silicon and do first and second coat after screeding? 

Also, which waterproofing membrane would you recommend for bathroom with shower area? the link you shared has many options with interior and exterior. Appreciate your recommendation. My bathroom is 1200 x 3000 size, will 4L membrane be enough for 2 coats? 

Thanks

Riz

[EricL]

Hello @sachinriz 

Please note that the screeding must be put down first before you apply any of the waterproofing. Remember to give the screeding enough time to cure, putting the waterproofing on too early will result in the moisture being trapped underneath and the screeding and it will not cure properly.

I suggest having a look at  Crommelin 4L Shower Waterproofing Membrane. It is a water-based, ready to use, heavy duty, modified rubber liquid applied membrane, engineered to permanently waterproof wet areas prior to tiling. If you are waterproofing your shower area only it should be enough. But if you are waterproofing other areas, you will require more than one bucket.

If you need further assistance, please let us know.

Eric