# Forum Home Renovation Tiling  Tiled shower floor slope query.

## mr nick

I'm in the process of doing a bathroom reno and am trying to figure out the best way forward with my shower base.
Ideally we want to go with a baseless shower with the bathroom floor tiles continuing through the shower floor. The floor is to be done in 600x600 tiles and the shower cubicle is 1200x900 frameless glass. Bathroom is ground floor on a concrete slab.
We quite like the look of linear grates for the dr
ain and on first look this seemed like an easy approach as it involves only a slope in one direction - we would be putting a 1200 grate along the back wall. But then I started to think about the fall which should be in the region of 15mm from front to back - easy enough if I was to be enclosed on three sides but I have glass on two sides. The 1200mm front with the door is no problem as that follows the same plane as the grate so I would just have to drop the floor 15mm to the back wall but I'm then left wondering what happens to the 900mm side panel. I guess I would have to sit it on the flat floor so that it doesn't have a 15mm lean back to the wall but I can't figure out how I would do the transition at the back where the grate would be 15mm below screen. I have looked at dozens of pictures to try and figure out how all this works but to my eye, they all look as though they don't have an adequate slope and thus that allows the screen to fit flush all round. The only ones that do have an obvious slope use a central drain with the obvious associated triangular cuts which I would like to avoid if at all possible. 
Not sure if I'm overthinking this and a simple solution is staring me in the face or whether it is a big task and I need to change my plans. Anybody able to offer tips on how they have or would approach this scenario?

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## barney118

Hi Mick, 
What size drain currently is coming our of the slab? Was there a shower there before? Ideally you should have 100mm pipe that has a P trap under it on top of the pipe you should have a puddle flange its about 200mm all up dia which sits level with the slab. You would need to buy  a water stop angle which should protrude 5mm above tile level fixed to the slab. Water proof the whole section then screed you floor base for tiling getting your fall right 1:100 to the waste from the door, dont worry about the side wall to grate as it covers the whole area. Install your grate drain, it just sits in the puddle flange there will be a gap between it and the outlet pipe as any water that gets under your tiles will flow to the puddle flange.
I am doing the same thing, I am glad I did some homework and I will be also buying a floor grate with the largest possible pipe outlet which is about 80mm. This is if there is a blockage you can get you hand down to remove it as you cant dig up the slab ! :Smilie:

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## Oldsaltoz

> I'm in the process of doing a bathroom reno and am trying to figure out the best way forward with my shower base.
> Ideally we want to go with a baseless shower with the bathroom floor tiles continuing through the shower floor. The floor is to be done in 600x600 tiles and the shower cubicle is 1200x900 frameless glass. Bathroom is ground floor on a concrete slab.
> We quite like the look of linear grates for the dr
> ain and on first look this seemed like an easy approach as it involves only a slope in one direction - we would be putting a 1200 grate along the back wall. But then I started to think about the fall which should be in the region of 15mm from front to back - easy enough if I was to be enclosed on three sides but I have glass on two sides. The 1200mm front with the door is no problem as that follows the same plane as the grate so I would just have to drop the floor 15mm to the back wall but I'm then left wondering what happens to the 900mm side panel. I guess I would have to sit it on the flat floor so that it doesn't have a 15mm lean back to the wall but I can't figure out how I would do the transition at the back where the grate would be 15mm below screen. I have looked at dozens of pictures to try and figure out how all this works but to my eye, they all look as though they don't have an adequate slope and thus that allows the screen to fit flush all round. The only ones that do have an obvious slope use a central drain with the obvious associated triangular cuts which I would like to avoid if at all possible. 
> Not sure if I'm overthinking this and a simple solution is staring me in the face or whether it is a big task and I need to change my plans. Anybody able to offer tips on how they have or would approach this scenario?

  To get the puddle flange that close ti the rear wall you will need to trim part of it off, it will need to be level or just below the level of the slab, I use a cup grinder to do thid, very dusty but it only takes a couple of minutes, mark the line using the flange and cut/grind around the perimeter line first then grind out the rest, leaving the centre a few mm lower than the outer extremities. Do NOT use the 4 securing holes or any screws, they may corrode and swell, this might cause a leak.
Run some sealant over the holes on the underside of the flange to seal them off completely and lightly tap the flange all the way down with a small hammer, then seal around the small gap left after grinding and put a thin film of sealant over the top of the puddle flange, this will provide a good key for the waterproofing as not much sticks to plastic. Wondercap make a 'retro fit' flange that works well for this application. The flange size must match the pipe size by the way.
The fall inside the shower should be one in 80, and one in 100 for all other areas.
The water stops should be installed before waterproofing, just stick them down with a sealant and run the waterproofing membrane up the inside after smearing a thin coat of sealant over the exposed bottom and upright angles.
The trough drain should be mounted flat and level, the fall to it will let the area drain without problems. You will need to us a sealant on the ends and back wall rather than a grout though.
I use Sikaflex 11FC (fast cure) on most jobs, and DoNot spit on your finger to smooth out any sealant, it has enzymes in it that will turn in yellow.
PS. wall tiles must overlap floor tiles. 
Good luck.   :Smilie:

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## mr nick

Firstly, thanks for the replies. A design change by the missus has put me behind schedule as I've had to relocate some plumbing and drains but I'm now back looking at the shower base. Still not 100% sure whether to go with the long grate or a central drain but I'll decide that when I start hacking away at the slab.  
My next query relates to the waterstop that is needed around the enclosure and across the doorway. Having done numerous searches, I've found lots of mention of how to install them etc but I can't figure out if the waterstop is just a basic bit of aluminium angle or is it an actual product? I found one place online that sold PVC stops of various sizes but that's about it so this leads me to believe that the stops are not a purpose made item - or are they? 
Also, while I know that for a frameless shower the waterstop can finish flush with the tiled surface, is there a minimum depth it must be set into the floor? As I'm on a slab, I will need to remove some concrete to gain the required slope but it's a question of how much and to what extents. For example, is is viable to fit a waterstop that is the same depth as my tile/adhesive (12mm is) around the perimeter of the enclosure and then grade the concrete down from there or would I need to cut out the slab to 50-75mm depth for the full extent of the enclosure and then fitting a deeper waterstop within the cut out and screeding the grade? Presumably the door threshold can use a shallow waterstop to match existing floor finishes but as this would theoretically need to deal with far less water (if any at all) then I'm not sure whether there is a differing requirement for the shower area. 
Any pointers will be greatly appreciated.

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## Oldsaltoz

> Firstly, thanks for the replies. A design change by the missus has put me behind schedule as I've had to relocate some plumbing and drains but I'm now back looking at the shower base. Still not 100% sure whether to go with the long grate or a central drain but I'll decide that when I start hacking away at the slab.  
> My next query relates to the waterstop that is needed around the enclosure and across the doorway. Having done numerous searches, I've found lots of mention of how to install them etc but I can't figure out if the waterstop is just a basic bit of aluminium angle or is it an actual product? I found one place online that sold PVC stops of various sizes but that's about it so this leads me to believe that the stops are not a purpose made item - or are they? 
> Also, while I know that for a frameless shower the waterstop can finish flush with the tiled surface, is there a minimum depth it must be set into the floor? As I'm on a slab, I will need to remove some concrete to gain the required slope but it's a question of how much and to what extents. For example, is is viable to fit a waterstop that is the same depth as my tile/adhesive (12mm is) around the perimeter of the enclosure and then grade the concrete down from there or would I need to cut out the slab to 50-75mm depth for the full extent of the enclosure and then fitting a deeper waterstop within the cut out and screeding the grade? Presumably the door threshold can use a shallow waterstop to match existing floor finishes but as this would theoretically need to deal with far less water (if any at all) then I'm not sure whether there is a differing requirement for the shower area. 
> Any pointers will be greatly appreciated.

  So you are looking to install a 'walk in' shower, (shower at or below the rest of the floor level in that room). 
Making a hollow in the slab is not the best method, it can lead to failure of the slab and is very hard work, not to mention a terrible mess. 
The most common and acceptable method is to place a 50 mm water stop in the doorway and screed the floor of the room. 
Water stops are a simple aluminium angle that has one side fixed to the floor and the other uptanding to the required level, a sealant is all that is required to stick it down onto the floor (I use Sikaflex 11FC) a shower water stop has the waterproofing membrane running up the inside of it to ensure no leakage. 
The size and thickness of the angle is determined by it's location, a standard doorway water stop would be 12 mm high with a base (the bit that is stuck to the floor) of 50mm, for a 10mm thick tile. 
A 50mm by 50mm angle can also be used around a new shower, fact is that when this method is used the resulting step up into the shower is minimal as the floor tiles around the outside will the 50mm angle by their depth plus glue at around 4mm leaving a step around 35mm.   
The alternative would be a 50mm angle for the shower and the doorway then screed to floor waste and shower waste, no steps other than the doorway, after a week you will not even notice the step in doorway. 
The shower needs a fall of 0ne in 80 and the rest of the room only needs one in 100. 
Also be advised that many of the long or slot drains on the market do not meet the Waterproofing Standards and can be all but impossible to seal properly because of the poor design. have a look at the 'the smart tile', it's the next best thing to no visible waste in a shower. 
Good luck and keep us all posted on your progress so others gain some insight into the task at hand..

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## mr nick

Hmmm. Given that my room currently has no floor waste and I hadn't been planning on retro fitting one, raising the entire floor by 50mm to achieve the slope in the shower area was not a task I had planned on. I had previously considered it but dismissed it due to the 'step' issue at the doorway. Looks like we need to have a rethink...

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