Bathroom Puddle flange

Morning all,

Looking for a definitive answer on installing a puddle flange.

I have seen a heap of videos on YouTube, and also read a heap of posts on Google in regards to puddle flanges and I get more and more confused each time. I had it in my head that a puddle flange is to be installed on top of a sloping screed in a bathroom and also waterproofed so that any water that may seep through the tiles etc can escape through the puddle flange. I have just recently started following a guy on YouTube that shares videos of tiling jobs and waterproofing, and he has told me that the puddle flange needs to be installed under the screed to the house substrate/slab. Does anyone know for sure if this info is correct? Watching gripset tips and tricks videos and he states it's either one or the other, and if the house slab has a puddle flange then the screed by code has to have one too.

Any info and opinions much appreciated.

Thanks
Geoff

Hi Geoff
Personally, I get the plumbing sorted first including the puddle flange, then have the tiler screed and then waterproof on top of screed and into puddle flanges.
To get the puddle flange to sit flush with the slab it's sometimes necessary to grind a little out of the slab. When the screed goes in it sits on top of the puddle flange and can be waterproofed into the the puddle flange while allowing plenty of space for the tiler to install whatever drain you have.

I always waterproof on top of the screed as I'd prefer to keep any water ingress to a minimum and having a big area of essentially wet screed sitting under my tiles doesn't appeal.
I know plenty waterproof under the screed but to me it makes sense to do it after screed. You also get the best junction between waterproofing and puddle flange if you go after as the water is always running down hill while under the screed is flat and doesn't always run to the drain.

Hi Geoff

Install Puddle Flange prior to any screed.
Puddle flange needs to be flush with the surface so you may need to grind away the surface to achieve this.
Also as per the AS3740 -2021 (waterproofing) The new standards require that the waterproofing be applied to a substrate with a minimum fall of 1.100
Previously you could water proof the substrate regardless if it had any falls then complete the screed above the waterproofing with the suitable falls and tile etc
This is no longer the case.
Also ensure you have water stops in place at the shower and door way. The water stop need to finish flash with the tile surface.
Hope this helps a little.

Kind regards
Robert
Clear View Property Inspections