Tiling Over Concealed Shower Mixer

[bjblackmore]

Hi,
We're in the middle of gutting and redecorating our bathroom, after the previous house owners used standard plasterboard, didn't tank or seal it, and just used non waterproof grout/adhesive on the tiles.

We've had to rip out the disintegrated plasterboard, and the bottom stud wall frame, which was rotten, replace some of the floor, and then fit a new Vaal Concealed Thermostatic Mixer Valve, and cover with proper waterproof tile backing board.

However, the instructions that came with the shower valve were minimal, just 5 bullet points really, and a small diagram showing the water inlets & outlet, and another showing the components/parts list. It said to fit the valve 72mm-85mm deep, into the wall. I think we did about half way after checking. However, now we've put the tile backer over it, I tihnk it's protruding out to far, below is a pic without the face plate. Shouldn't the brass body be hidden behind the backing board? Having put a tile on the wall to see how far out they stick, I think it's going to stick out to much.

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We need to cut a hole in the tile, to fit around, but I think this should just be 2 holes for the taps, looking at this, it'll have to be a bigger cut out, shown below, to go around the whole thing wouldn't it?

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This is what it looks like with the face plate on:

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The main reason for setting it at the level we did, was because the water outlet seems very far in, even with a coupler attached, the shower hose connector just barely sits above the level of the tiles. If you look int he pic below, the fixing nut, that should screw against the tile wall is probably already going to be very tight in.

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Below is a quick diagram of how it's connected, probably not to scale, but gives a clue as to how it looks side on.

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Can anyone suggest any advice? Should I cut the tile backer again, and set the valve in deeper? If so, how can I then increase the length of the outlet, so it sits further out than it does currently?

 

[brett71]

I am doing something similar, and i would say when you tile the area around it as long as the face plate and shower head attachment sit flush onto the tiles it will be fine

 

[bjblackmore]

I'm hoping so! My concern is the very top, there's only about 5mm between the edge of the face plate, and the top of the valve. And I also have a horrible feeling that the top of the valve is going to be right on the edge of a tile, or maybe even past it, which means the top of the faceplate will be sat right on the grout join, which could cause it to leak!

I think I'm going to change the coupler on the shower head attachment for a small piece of longer copper pipe. It'll be fiddly, tightening the compression fittings, but it'll give it a couple of extra mm for a tile to fit behind!

 

[AdamCH]

You need to be able to get at the brass bits for any servicing so they aren't tiled over. Mixers from Grohe & Dornbracht come with plastic shrouds that protect the fitting during installation, ensure that the installation depth is within the range, provide an edge to tile up to and with the supplied membrane, provide a waterproof seal so that water doesn't creep in.

Where the grout lines fall all comes down to planning - ideally before you fix the mixer to the wall but you can still adjust where the tiles fall if you haven't started.

 

[bjblackmore]

Hi,

Just an update to the above, I managed to get the tiling done. Hired a diamond tile hole cutter, cut the hole for the 2 knobs & outlet, and fitted the front panel. All seems OK so far! Although I still need to fit the shower wall elbow, as the one suppled was chrome effect plastic, and but the time I'd tested it, screwing it on, and off again, the plastic thread was knackered, so I've ordered a new brass/chrome wall elbow! Pics below:

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One other question, is it worth running silicone sealant down the corner join of the tiles, and also along where the tiles meet the shower tray? It's currently grouted, and the grout is for showers & wet rooms, so is waterproof. I'm not sure silicone would add anything to the corner join. But I'm not sure about the tile/shower tray join. Is it worth it? The tiles are on top of the tray, the tray isn't pushed against the tiles, which it probably looks like from the pic. The tray was pushed against the bare aquapanel and had Aquaseal stuck between it and the wall first. Then the tiles were put over the top. Pic of the corner & tray below:

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[Nozzle]

It doesn't need to be pretty behind the face plate, just approximately the right shape. Clearly the face plate will hide rough edges.

I had a similar query a few years back
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Nozzle

 

[bjblackmore]

Yeah, it wasn't particularily pretty behind, just cut 4 holes, 2 big for the hot/cold & on/off knobs, and 2 smaller for access to the valve/filters.

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One thing I wasn't sure of, was where to silicone, as the face plate has foam around the inner edge, so I put the sealant inside that, around the edge of the holes. It does mean the foam will potentially get wet!