Building wall next to bath - advice please

[Flummoxed]

Hi folks - I haven't lurked or contributed to this group for a while, but I thought I'd ask for advice on this point.

It would be easier to draw a diagram, but basically we are planning to change out bathroom. What I want to do is replace the old bath, washbasin and toilet, but not just replace them in situ as we've done before, but I want to add one of those units that look a bit like a narrow version of a kitchen base unit and worktop, that the basin fits into, and the toilet will back onto (with the cistern concealed in the unit). Hope that makes sense.

Anyway - currently, if you imagine looking L-R at the configuration, towards the wall in front of you, we have the bath on the left (taps/ plug end against the wall), then in the middle the washbasin, then the toilet on the right. I want to keep more or less the same layout L-R, but with some slight changes (we've considered other options but for various reasons none of them would work very well - it's only a small bathroom).

As I said, we want to put a unit behind the basin and toilet. The unit will stick out a bit from the wall, and the basin will half be set into the unti with the front of the basin sticking out. The toilet will of course back onto the unit as above.

There is currently some space between the foot of the bath and the wall 'behind' you as you look towards the wall ahead.

What we want to do is move the bath backwards toward the 'back' wall, leaving a gap at the 'top' end of the bath. Then I want to build a stud wall behind the bath, tile it and have a mixer shower (or even a shower head on the stud wall, with pipework behind). The idea is to bring the bath end more or less level with the 'unit'. Why? because we want to fit a hinged glass screen, which we could open outwards. This wouldn't be possible if we left the bath where it is, hence the plan to move it away from the wall.

Hope all that makes sense.

Now, what I mainly need advice on is the building/positioning of the stud wall. I need to find out:

- how best to position the studwork, allowing for board to cover it and tiles? i.e. how much clearance to be allowed between studwork and bath?

- best materials to cover it with, bearing in mind need to tile over it (plasterboard? MDF? etc.)

I'd also be interested in advice on how to prevent leaks around the edge of the bath, something we've suffered from in the past. Ideally I'd like to get a bath with an 'upstand' around the 2 or 3 wall edges, but I don't know if these exist. Failing that, maybe it's better to chase it into the wall, and then tile down to it? Or not? I'm fed up with those plastic strips that don't always work properly and look a bit naff, IMO, and would prefer to have a more 'permanent' solution.

Any advice would be very welcome.

Thanks in advance

Flummoxed

[Robert Laws]

On Jan 29, 12:19 pm, "Flummoxed" wrote: ..

We are halfway through doing something very similar. We are putting a 'back to wall' loo (but floor standing) again the unit with the flush inside the unit, plus a recessed basin in the unit to the right. We plan to build the 'unit' out of 18mm marine ply. We also plan to use marine ply to move one wall so it comes right up to the bath. the bath will then be walled on three sides with a fixed shower screen at the tap end.

We then plan to have the whole lot tiled. At the time of tiling, the bath will be fixed in but the basin and loo will be 'loose' - apparently this is what the tiler wants.

one further point: to give access to the pumbing we plan to make the 'worktop' of the unit removabale, complete with the basin. This means that the basin will have flexible pipes. We think this is better than having an access hole with loose lid as the whole 'worktop' can be made to have a more watertight snug fit.

but as to your question: We plan to fix the bath up against the wall on three sides and then to tile down to it with a sealant bead around it. two side are block/plaster walls already, with the plaster coming down only as far as just above the bath. the third wall will be the marine ply one.

if you'd like to compare notes in more detail please email me on laws at bcs dot org dot uk,

Robert

[Flummoxed]

similar. We are putting a

Thanks for the helpful response Robert - that was quick! I assume you chose marine ply as the best option for the stud wall based on a recommendation? I admit I hadn't looked into it. I guess it needs to be strong and fairly rigid, to take tiling.

As for the bath, we would be planning to do something similar to you, i.e. have 3 walls round the bath. It sounds as if it's a good idea to chase the bath end/sides into the wall, so the plaster on the wall above would stand out above the edge of the bath - have I understood correctly? In that case it sounds as if it would also be a good idea to have the marine ply standing out slightly above the end of the bath too. Then You can tile right down to the bath and seal it as you say.

[EricP]

On 29 Jan 2007 04:19:52 -0800, "Flummoxed" wrote: Having gone down the route of building flimsy walls around the bath, can i recommend that you abandon the wood construction and think of a solid wall from Thremalite blocks. They are a quid each and light as a feather, easy to work with a saw and build nice solid walls that dont flex and crack grout around the bath.

[sm_jamieson]

The plastic strips over the top of the tiles are totally useless as you have realised. However, there are types where the upstand on the strip goes behind the tiles, and you silicone the bottom part onto the bath. These are very good to prevent leaks, but some think they look .. naff. The most important thing is that the bath is fixed very rigidly and that it cannot move much relative to the wall. This can be hard to achieve with cheap plastic baths. I always have a timber frame of some sort to support the bath around the edges and screw to the wall where possible. If the bath is rigid enough, put a thick bead of silicone in the "groove" where the bath meets the wall (you can almost glue the bath to the wall with it). Try to have the upper edge of the bead sloping towards the bath. Then tile down to the bath, leaving a small gap. Then put a final silcone bead around the bath/tile interface and into the gap. You cannot do much better than that. The standard idea of filling the bath before you do the bead is a good idea, since the gap will then be at its widest, and the silcone will be compressed rather than stretched, which could pull away from the wall. But if the bath is rigid enough, it won't move anyway ! I'm just finishing my bathroom, not sure yet to use the under-tile strip or not at this point. Simon.

[Robert Laws]

EricP, That's interesting. I hadn't though of doing that. However, in my case, the wall I am extending inwards is an external wall made of wood (it's a 1960s house) so it would be rather odd to have thermalite inside and then the existing plywood outside (with tiles outside that).

I tend to like marine ply because I used to live on a boat where things must be damp-proof and the previous bathroom disintegrated from the wet. marine ply is very stiff and I think tiles would stick OK. I am also reluctant to 'build' with bricks/mortar/plastering because I lack the skills. but maybe I should pay someone to do it, or learn.

Flummoxed: I had not fully decided how to bring the ply down to the bath, but yes it could stop just overlapping the top of the bath much as the plaster does on the other two walls.

Robert

[The Natural Philosopher]

similar. We are putting a

I have used both 19mm ply and also MDF for stud walls to be a bit structural to take baths and tiling.

I make bath enclosures out of 15mm MDF mostly, on a stud frame. Nice if painted, nicer if tiled. Go right up to the bath edge and screw battens on to support the bath lip everywhere. Stiffen weak flimsy baths with bits of scrap MDF stick on with car body filler.

When done, use silicone to seal the edges and lock bath in place even more, then tile overall. Use grout at the bath edge..yes it cracks, a little as the bath flexes away, but it doesn't go mouldy: If can be arsed, full bath to brim when grouting..thats usually as far as bath will ever flex.

MDF is a great material for bathroom fitouts - paints like plaster, is fully structural, and will take splashes well enough..and is MUCH flatter than any plasterer can skim. And its relatively cheap and its strong. Only downside is that large butted panels will show a crack line at the edges one day.

Use plasterboard for non critical tiled areas. Use 19mm ply for really strong bits like shower base trays or floor recovering before tiling and the like.

[John Rumm]

With a a bath it is indeed better to chase into the wall (this adds rigidity to the bath as well), and then tile down to it. This tends to "hide" the roll edge of the bath, and leave a flat surface to tile to - hence eliminating one of the potential moisture traps at the edge.

If you tile down to the bath, leave a tiles thickness gap at the bottom of the tile. Then when sealing, fill the bath with water first (to set it at its lowest position), and then seal with a good quality silicone. Don't let the water out until it is fully cured. This will ensure the natural state of the silicone is slightly under compression, relaxing as you fill the bath, rather than streatching (and hence more likely to fail) as you fill it. The tile's width gap will also ensure the selant gets a good solid key.

[John Rumm]

For general building use marine ply is typically overkill, and a waste of money. WBP ply is more than adequate.

[Alex]

Check out a product called hardibacker on sale at travis perkins and topps tiles,totaly impervious to water and you can tile straight on it,used it to line my shower

[Robert Laws]

indeed better to chase into the wall (this adds

Would you roughen the surface of the bath with sandpaper to help the silicone to key? I mean the part that will be hidden under the sealant of course!

Robert

[John Rumm]

I have not bothered in the past. You can apply a beading layer between the (cut out) wall and the bath edge. Then a second one after the tiles are in place. The bedding layer and the bit in the gap under tiles is not going to move, so extra adhesion is not really a problem.

[Flummoxed]

Thanks for all the advice folks. Sorry I didn't respond till now, but I've only just checked back here. Once again, some good useful comments to think about from this group.

Cheers

Flummoxed