Adhesive for 300 x 600 x 10 Slate Tiles - Larsen used and no good

[Dean Pedder]

Hi.. I am tiling around a bath floor to ceiling with large slate tiles... The supplier provided Larsen Grey Flexible Rapid Set Adhesive C2F S1 - 20Kg. This has not provided good adhesion to the plaster walls and I'd had to remove tile and ahesive and reaply.... Came home last night and one of the tiles had fallen off the wall and damaged the new whirlpool bath.... I therefore looking for help on the best adhesive for the tiles and any kind of primer I should use on the walls first before laying tiles... I'm not at all impressed with the Larsen product, but the supplier said it was great and that they use it for all their swimming pool jobs etcm so I thought it would be suitable for use around bath and shower area... Thanks for any advise... Dean

 

[Gazzer]

Last time I used Larsen it was a good adhesive. I never had issues at all.
Did you prime the walls before tiling? If so can you explain your priming methods ?

Also you say you are fixing 300 x 600 slate to plastered walls. Are you aware of weight limits for tiling ?

 

[doug boardley]

if your walls were plastered, the slate tiles would be too heavy anyway.

 

[Stewart]

I use Larson's all the time and haven't had a single failure....... As above, slate too heavy for plaster and-or priming issue.

 

[Gazzatile]

As the others slate could be too heavy for the plaster and not adhesive problem

 

[jay]

was the plasterboard top coated
and i agree with others the slate is to heavy for plasterboard

 

[Dean Pedder]

Last time I used Larsen it was a good adhesive. I never had issues at all.
Did you prime the walls before tiling? If so can you explain your priming methods ?

Also you say you are fixing 300 x 600 slate to plastered walls. Are you aware of weight limits for tiling ?

Yes... I think it's 20kg per m2... each tile is around 4.8kg

 

[Dean Pedder]

I use Larson's all the time and haven't had a single failure....... As above, slate too heavy for plaster and-or priming issue.

Hi... I didn't use any primer... I called Larson technical today and they said that I needed to use normal setting adhesive rather than rapid and also use a primer with the product.... What I'm after is some guidance then... I want to tile the walls from above the bath to the ceiling... what do I need to do? Apply a primer, remove the plaster and tile directly onto the plasterboard or board over the existing plaster so that the substrate provides enough key for suitable adhesion....? Also, what is the best adhesive for the job? I have used Ultra before on limestone flooring and got good results... As I say, I'm not impressed with Larson.... I am removing the tiles tomorrow to avoid any more accidents! Thanks, Dean

 

[DHTiling]

Hi Dean..

You say the tile fell off.. was any adhesive on the tile or just on the wall.? and what method if fixing did you use.?

 

[Dean Pedder]

Hi Dean..

You say the tile fell off.. was any adhesive on the tile or just on the wall.? and what method if fixing did you use.?

The adhesive was fully on the tile and none was left on the plaster... adhesive was applied to the tile with a notched trowel and tile applied to wall with a twist... what I am thinking is that the plaster needs to be primed or I need to place backer board on the wall to be 100% sure... what adhesive do you recommend...? mapei looks the best to be... Thanks, Dean

 

[DHTiling]

Ok, So no primer was applied..

what finish is on the plaster.. is it dusty or is it quite shiny..?

 

[Dean Pedder]

Ok, So no primer was applied..

what finish is on the plaster.. is it dusty or is it quite shiny..?

Hi Dave.... Probably more dusty than shiny as it I sanded the matt emulsion off it before tiling.... Thanks, Dean

 

[DHTiling]

Ah right.. what has happened is the dust has prohibited adhesion of the adhesive..

prime with a suitable acrylic primer( instructions on the bottle) and then start again.. make sure you get full contact and i do hope you have got your weights correct..

Also dean, let us know how it goes mate.. maybe some pics hey.?

 

[Dean Pedder]

Ah right.. what has happened is the dust has prohibited adhesion of the adhesive..

prime with a suitable acrylic primer( instructions on the bottle) and then start again.. make sure you get full contact and i do hope you have got your weights correct..

Also dean, let us know how it goes mate.. maybe so me pics hey.?

Thanks Dave.. will do - I have some pics before the tiles started falling off! I think I will be belt and braces with this one and install some no more ply backing boards... I'm not worried about damage to the new whirlpool (although a pain), more worried if someone had been in the bath and a 5kg slate tile would have landed on their heads - not a good situation... I'll opt for backing boards and Mapei adhesive for the walls and save the Larsen for the floor area... Pics to follow... Thanks, Dean

 

[DHTiling]

If you want, Mapei kera-flex maxi is a good one for stone.. work clean and seal before you grout..

Look forward to the pics.. if you need any more advice then just ask dean.. always someone about to help..