1cm mosaics on Impey Tray

[Daveyboy]

I've been asked to price up an insurance job, which involves replacing a raised shower platform made of wood with a plywood covering (H 0.10cm x W 0.75cm x L 2.1cm) tiled with 1x1cm glass mosaic tiles, that currently slopes down into a pebbled filled gulley, with a central glass wall (W 0.9cmx H 2.03cm) secured to the shower platform and ceiling, that provides access either side. The installation failed due to water getting in under the mosaics and rotting the plywood, then water going through the ceiling below.

The floor still needs to be raised to get enough run-off for the waste pipe but this time an 1850 x 900 Impey tray is to be used with a central waste position, no pebbled filled gully . The tray will not fit wall to wall and the platform will need to be built up both sides with a slight incline towards the centre of the tray/waste. Tiling to be as before (the client has been told the mosaic tiles are suitable for this type of installation). The glass wall to be fitted to the Impey tray and ceiling as before.

I've installed a number of Impey trays but never with mosaics this small and I'm concerned that I'm not going to be able to get a flat finish with these tiles and that they won't last. The problems I foresee are:

• The tanking method of the impey trays, where you have to overlap corners/edges/joints, which creates ridges. With bigger tiles these ridges are not an issue as they are absorbed within the adhesive bed, but this is not possible with such small mosaics; they would simply sink into the adhesive.
• The flexibility of the tanking membrane. Because the mosaics are so small and so many and have to be fitted with a slim bed of adhesive, there may be too much movement in the membrane that will crack the grouting.

Does anyone have any experience of this sort of tiling, am I worrying about nothing? Any solutions?

 

[faithhealer]

See your problems Davey. Can they be talked into a bigger mosaic, Sounds like the insurance paid out on a shoddy job!

 

[Daveyboy]

Hi faithhealer..When I looked at the job, I told them I would have a problem guarranteeing my work if I had to lay such small mosaics on a raised platform and in a wet area - just too much flex for my liking - and recommended larger mosaics or tiles or a coloured tray. Unfortunately, the client really wants the same tiles and has been told Impey trays will be fine for them to be used.

Maybe Wetdecs knows how to overcome my concerns - apart from turning down the job! :stupid:

 

[sWe]

Skim over the ridges with some rapid set and let it harden before you start with the mosaics.

The flexibility of the tanking membrane shouldn't be an issue at all. The real issue is wether or not the substrate is stable and rigid enough. What waterproofing system are you using? Could you link to a product spec/installation guide?

 

[Daveyboy]

Cheers sWe, that thought had crossed my mind but was still concerned about the possible flex in the tanking membrane. The membrane comes with the Impey tray and is a very sticky rubberised sheet, with thinner strips to go round the edges of the wet area. One side has a peelable paper (this gets stuck to the primed floor) and the other side has a peelable clear plastic (which you remove then tile onto the membrane). The rubberised sheet does flex/squash when it is laid but this has not been an issue with bigger tiles/thicker bed of adhesive. Perhaps skimming the whole tray would firm up the membrane?

The substrate on which the impey tray will rest, will be a raised wooden platform, built on top of the existing wood floor, so there will be some degree of flex. I suspect more than one person will use it at the same time (they seem an active couple!) so there will be some weight/movement going on above the tray.

Will try to find a link/product speck..

 

[andy-p]

davy !! ive fitted mosaics on aquadecs, , skim the membrane with spf and let it set, spend a bit of time gettin it right, as you have to avoid ponding, it took me a full shift to tile and grout the aquadec area ,its quite tricky so dont rush and take your time...

 

[sWe]

Cheers sWe, that thought had crossed my mind but was still concerned about the possible flex in the tanking membrane. The membrane comes with the Impey tray and is a very sticky rubberised sheet, with thinner strips to go round the edges of the wet area. One side has a peelable paper (this gets stuck to the primed floor) and the other side has a peelable clear plastic (which you remove then tile onto the membrane). The rubberised sheet does flex/squash when it is laid but this has not been an issue with bigger tiles/thicker bed of adhesive. Perhaps skimming the whole tray would firm up the membrane?

The large sheet is about 40x40cm and about 2mm thick, right? I use those all the time, as they're mandatory over here. I still don't think it's the membrane you should be worrying about, but rather the tray. Use a flexible adhesive and you should be ok, as long as the tray is rigid enough. If you're going to skim the ridges, then skim the whole tray as well if it makes you feel on the safe side.

 

[Thespanishtiler]

on wet room floors and walls i always use a solid bed trowel with the carbide runner tips at each end, this gives a full bed of addy that covers the tanking lips and leaves a bed of 3, 4, 0r 5mm notches on top to bed the mosiacs onto then press home with an epoxy grout float or similar. feathering the lips with spf prior to tiling also helps. I think genisis make a carbide tipped trowel or you can braze runners onto a standard steel trowel.

 

[andy-p]

i use a karl dahm flowline trowel on mosaics on floors, it gives a solid bed..

 

[Spirit]

An alternative would be to use an 'On The Level' tray, which doesn't have the ridge problem.

 

[Daveyboy]

Cheers for that Spirit..having a look at their website now..

 

[Spirit]

Tell them that Andy from Guernsey says "Hi"

I have always had A1 service.

 

[wetdec]

Hi

I would not use tilesafe but swap for dura-wp tanking membrane, by doing this you dont have the compressive concern you have with the bitumen and high build in the corners.

Rough up the surface of the former to create a key then stick the dura-wp to the surface with an F Ball vinyl adhesive like F33 (check this). put it on with a fine trowel then roller it before putting the dura-wp over the top. ( this is also a good way of reducing height on weyroc and ply floors using dura-ci)

You then have your former with the membrane bonded direct and leaving an overhang allows you to secure around.

Fix the mosaics with a mosaic adhesive/grout and your fix will be good


tiler

..

 

[Daveyboy]

Cheers Wetdec, much appreciated...