Unibond problem

[DaveWall555]

Hi all - hope someone can help, just fitted a pre shaped/sloped shower board 1200x1200 to replace the floor in my shower - I've tiled the floor using a unibond pre mixed tile adhesive and grout. This was about a week ago, I've then grouted the tiles (and apart from leaving the grout slightly too long and it being a pig to get off) this seemed OK, however standing on the floor I'm sure I can feel some flex....

The pre shaped board, is a sort of fiberglass foam board (A genuine shower tray) and the tiles are 50mm x 500mm I'm just concerned that the floor wont be water tight...???

Any advice much welcomed!

 

[DaveWall555]

I'm also convinced one of the tiles has a bit of movement i.e. not stuck properly.... Any tips???? is this normal????

 

[bathstyle]

What make is this shower board? where did you get it from? most of the wet room formers require tanking before tiling. Unibond ready mixed tile adhesive is far from an ideal product.

 

[DaveWall555]

Hi, thanks, it was a MARMOX shower board or something like that...

Will have a look on their website again, but didn't see 'tanking' in any of thier diagrams....????

 

[Richard C]

The pre-formed tray must be fully supported, did you follow Marmox installation instructions? It should not be flexing, if it is I think you’re doomed to early tile failure. Although the pre-formed tray itself is waterproof, you should also have tanked between the top of the tray & at least part way up the walls before tiling.

The adhesive/grout product you’ve used is a poor choice for tiling any area let alone a wet tray; you really need to use quality trade products for this type of application. Combined adhesive/grout product is completely unsuitable for this type of installation.

 

[bathstyle]

Yes, the marmox alone does not need tanking, are your tiles mosaic? The marmox will only accept a minimum 2" (50mm) tile, due to point loading.

I have a marmox wet room in my own house, as with all of these wet room formers, very time consuming to install, describe how you installled it so we can advise you if/where you have gone wrong

 

[DaveWall555]

Hi there - cheers guys, I did follow all the maxmox instructions regarding the fitting of the board - its fully supported by P5 water resistant T&G floor boards on good joists. I made and cemented the trap in a small box under the off set trap pre done hole in the board, that all lined up nicely, I've sealed about 25cm up each wall with a waterproof sealer from the same place and the rest of the space was already tiled frmo the previous shower...

When I say flex, this is MINIMAL, just enough if you put your eye level with the board, and get someone to stand on it you can notice it - I cant believe with the construction of the Marmox that this would be avilable - the filling between the top and bottom layer can flex...

I think the issue may just be that the grout/adhesive is a bit crap, certainly crap for this installation - I guess I'm saved by the Marmox board, but may have to re-visit the tiling sooner than expected with a decent trade adhesive and grout I guess

Dave

 

[Richard C]

You seem to have done it mostly right but I’ve got to be honest & say I’ve not personally fitted one of these before so I wouldn’t know what to expect by way of flexing. Looking at the spec sheet, you seem to have ticked all the boxes but there shouldn’t be any perceivable flex & your problem maybe more to do with choice of tiling product. Its probably best flushed down the loo but on 2nd thoughts, probably not a good idea as it may give you a drainage problem

Using top quality products really is the key on any installation if it’s to last, probably more so here. See how it goes (probably not well from what you’ve said) but if you end up stripping it back, have another look at the flexing before you do it again; you may need some additional support or go to a latex based product which is, unfortunately, more expensive.

 

[DaveWall555]

Thanks Richard, much appreciated, I'm wondering if it is worth stripping the grout back as much as possible then re-grouting with a decent product...

Whats top of the range for floor tiles these days???


P.s the Tiles aren't the best, but are far far from the worst...

Dave


P.s.s. the Marmox Board is made well with good instructions, I just wish I had come here before picking the unibond stuff.... Doh... Thanks again