Liquid or sheet membrane for shower pan?

My old shower base cracked so I ripped it out. Underneath it was totally rotten, with no evidence of waterproofing. I’ve removed all mortar and levelled. My plan is to construct a shower curb (concrete paver bricks) and a shower pan, then tile. I’ve seen many videos where a sheet membrane is installed in the pan. My question is, does it need to be a sheet membrane, or can a correctly installed liquid membrane be used, ensuring that it overlaps into the drain so the pan can weep any moisture?

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MitchellMc

Welcome to the Bunnings Workshop community @Gibbo1. It's great to have you join us, and many thanks for your question about installing shower waterproofing.

You might like to provide some images of where you're currently at so our members better understand the situation. Check out these helpful step-by-step guides on How to waterproof your shower and How to waterproof your bathroom. I'm unaware of any regulations that state it must be a sheet membrane. However, the waterproofing must adhere to regulations.

Let me mention one of our knowledgeable members @Vis-á-vis to get their thoughts.

Please let me know if you have further questions.

Mitchell

Gibbo1

Thanks Mitchell, photo uploaded

MitchellMc

Thanks for that image, @Gibbo1. Could you let us know what's happening with the corner pipe outlet? Is that you waste? What sort of drain was in this shower before? Is there an outlet on the floor in the middle?

Mitchell

Gibbo1

The drain was in the corner of the pan. There was a 90 degree elbow and the drain screwed straight in. My plan was to install a similar elbow, then a flange, then the drain.

MitchellMc

I'm a little concerned about how you will make this work with that drain height @Gibbo1. Are you planning on raising the height of the existing floor to suit?

Please be aware that according to code, you can't just waterproof the exposed shower area. I understand that you didn't find evidence of any waterproofing before, but a waterproofing membrane must extend out from the shower floor to the rest of the bathroom. It also needs to be one continuous coating up your walls. To do this correctly, all your tiles need to come off. Given this, you might wish to consider a shower base. It will have its own waterproofing requirements but might be easier to deal with, given the height of your drain outlet.

Mitchell

Gibbo1

Thanks Mitchell. Yes the plan was to raise the bed and waterproof. I don’t fancy stripping down the entire bathroom, so I’ll grab a shower base. Thanks for the advice, very helpful.

Vis-á-vis

@Gibbo1

Hi,

How are you going to install a shower base with the existing tiles on the wall? It would need to be rebated into your wall framing, wall sheets should then extend down to the lip of the base, sealed with a polyuretane sealant, then waterproofing to meet the base, then tiles over the lip of the base and then silicone to seal the joint between tiles and shower base.

If you leave your tiles insitu then it is impossible to get a long-lasting watertight seal between your shower walls and shower base.

The drain being where it is is a very poor design and no wonder you have had issues. Having a drain at the external perimeter of a shower is a very bad idea.

How do you plan in sealing the shower base to your hob? All shower bases have an outlet at the centre or at the wall. You would have to put the shower base in back to front to make it work and that will cause you no end of issues trying to send the water into your bathroom.

You really need to rip everything out to have any chance of getting a watertight shower.

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