Thread: Bathroom Puddle flange

Depends on where your waterproof membrane is, if it is under the screed then yes the puddle flange needs to be under the screed.

Originally Posted by droog

Depends on where your waterproof membrane is, if it is under the screed then yes the puddle flange needs to be under the screed.

Thanks for the reply.

I'd imagine the waterproof 9 times out of 10 it goes on top of the screed?

Originally Posted by garfield

I'd imagine the waterproof 9 times out of 10 it goes on top of the screed?

Don't know, but that's how I did mine. Hasn't leaked in 20 years.

Originally Posted by garfield

Thanks for the reply.

I'd imagine the waterproof 9 times out of 10 it goes on top of the screed?

With the building industry 9 out of 10 will be screed over. Reason being screed needs to dry in order to apply membrane, quicker turn around if you membrane then screed.

Plenty of discussion, pros and cons as well as membrane above and below on the old forum.

The usual process is the membrane goes under the screed so the the area is tanked , the puddle flange if required will be under the membrane
As Droog said part of the reason is so the tiler does not have to attend site twice but I think it is more common in Victoria

On first floor bathrooms we used to set up all our angles and membrane as per the code before the tile bed but had an arrangement with out tiler to membrane the screed also before gluing the floor tiles down for good measure and to stop the bed from getting waterlogged

Before the screed

Originally Posted by Beardy

...had an arrangement with out tiler to membrane the screed also before gluing the floor tiles down for good measure and to stop the bed from getting waterlogged

That's why I applied the membrane over the screed. You need to make sure the tiler uses the appropriate tile adhesive though. Some aren't suitable for use on a membrane. That was the case 20 years ago at any rate.

Originally Posted by jack620

That's why I applied the membrane over the screed. You need to make sure the tiler uses the appropriate tile adhesive though. Some aren't suitable for use on a membrane. That was the case 20 years ago at any rate.

There are a lot more products and options to choose from now, some of the glue manufacturers also do membranes so you don’t have compatibility issues

When I redid my bathroom, I waterproofed under, then put the screed in, waited a few weeks for the screed to cure properly, then waterproofed over the top as well.
Not everyone will have the luxury of being able to wait that long, but we just used the ensuite for the duration of the main bathroom reno. No kids at home .

When we reno’d the ensuite a few years previous, got a tiler in to do the job and I TA’d for him. He waterproofed under the screed, then tiled 2 days after the screed was laid, I am not keen on that method, as I reckon the screed is constantly wet now. It hasn’t caused any problems yet, as far as I know.

Originally Posted by garfield

Looking for a definitive answer on installing a puddle flange.

Here's the relevant section of a certain document that you should find useful.

Thanks for all of the replies guys, really seems like there is mixed views on how it should be done.

I thought the waterproof was done on top of the screed which caught any water seepage that would possibly get through the grout, the water could then run down as a secondary water catch. If the waterproof was on the house slab and waterproofed into the puddle flange beneath the screed and tile bed how would the water get away, as the house slab isn't slopped to allow water to seep into the puddle flange?

My current bathroom I have just started demolition and it was built in 1998, the shower section is the old style brick hob down the bottom, ask I started trying to lift the floor tiles it came off in sections because water must have been getting through for some time, underneath it was fibreglass, well the amount of water that was pooled up and had nowhere to go because the slab that was fibreglassed was not slopes to the drain, obviously as the drain pipe with the grate is higher than the fibreglass.

Screed is obviously put down and designed to run a fall for water towards the drain. If there's water getting through the tile bed which would then seep through the screed, where and how does the water get away?

Originally Posted by garfield

Thanks for all of the replies guys, really seems like there is mixed views on how it should be done.

I thought the waterproof was done on top of the screed which caught any water seepage that would possibly get through the grout, the water could then run down as a secondary water catch. If the waterproof was on the house slab and waterproofed into the puddle flange beneath the screed and tile bed how would the water get away, as the house slab isn't slopped to allow water to seep into the puddle flange?

My current bathroom I have just started demolition and it was built in 1998, the shower section is the old style brick hob down the bottom, ask I started trying to lift the floor tiles it came off in sections because water must have been getting through for some time, underneath it was fibreglass, well the amount of water that was pooled up and had nowhere to go because the slab that was fibreglassed was not slopes to the drain, obviously as the drain pipe with the grate is higher than the fibreglass.

Screed is obviously put down and designed to run a fall for water towards the drain. If there's water getting through the tile bed which would then seep through the screed, where and how does the water get away?

Either drill 4x6mm holes in pipe just above or at the puddle flange,
or slot the pipe before the grate slips into place.

Before water proofing membranes and liquid sealers were introduced, copper trays were used with a flanged brass grate silver soldered to the tray.
This meant, as you have questioned, water would saturate the bed to a height of 6-8 mm but was considered at the time to be the best option.
Tilers would(and maybe still do) bed the tiles in a wet base/screed.
Last shower I did was 2003 and I did the base tiles this way.

Originally Posted by garfield

If there's water getting through the tile bed which would then seep through the screed, where and how does the water get away?

It doesn't. The main thing is that it can't get through the barrier to damage the underlying building materials. Barrier on top of the screed is the way to go, and if you're doing it yourself you don't have to worry about the cost of having to get the tiler back twice to complete the job.

Originally Posted by rambunctious

Either drill 4x6mm holes in pipe just above or at the puddle flange,
or slot the pipe before the grate slips into place.

Puddle flange adaptors are deigned so the water can pass between the puddle flange and the adaptor:

Puddle Flange To Brass Waste Adaptor 100mm - NATFW677

Just make sure you don't fill the gap with tile glue.