Tiling onto lath and plaster

[Gazebo]

Greetings again to all you kind people on this forum, i have another problem with regards to tiling onto a lath and plaster wall, i am fitting a shower over bath (which will be used on a daily basis) one wall is brick and plaster the other is an internal lath and plaster stud wall. I am having to batten out the solid wall to house the concealed shower valve and pipework which i will then board with 12.5mm marmox board, but the lath and plaster wall is causing me a problem, it is possibly blown in a couple of spots but mainly it is the flex in the wall which i am worried about,will i be able to tile straight onto this using a SPF addy or will i need to tank it.?(only ever used Impey tilesafe before though) will the wall be strong enough for large slate tiles,.? would i be able to overboard the area of wall to be tiled with marmox or green moisture board maybe fixing with SPF and mechanically fixing into whatever studwork is there.? i am trying to avoid ripping the wall off as the ceiling has already been skimmed and painted and the wall in question is not due to be tiled in its entire length/height. the customer is proposing large format slate wall and floor tiles, (oh goody..! and tips with these would also be appreiciated, can you get reasonably priced calibrated,graded and sealed types of these.?)
Many Thanks
Gary.

:huh2:

 

[Olz]

Mate, i dont think that the lath and plaster wall is very strong at all, and i defo wouldnt be putting slate onto it even to half height, A skimmed plaster wall over plasterboard can take approx 20KG / m2 this includes addy and grout aswell at around 4kg/m2 and 2kg / m2 respectivley. Id be ripping the lathes off and fixing a cement board like hardibacker or aqua panel which is strong enough to hold around 45 - 55 kg/m2.

Some info on the weight ratings is here

 

[grumpygrouter]

Oli is absolutely right in his response. Do not put slate onto lath plaster, it is too heavy.

You will be easier to rip out the L&P and board out anyway as it is horrible stuff to try and prepare for tiling.

 

[Derry]

Hi, welcome to the forums

 

[Olz]

Oh and welcome to the forum mate, sorry forgot to say Hi

Let us know how you get on, with Pics if you can :hurray:

 

[monty]

Hello and welcome to the forums...

 

[graham31]

Welcome to the forums :hurray:

 

[White Room]

Lath and plaster was not in the design stage for heavy weight tiles

 

[Gazebo]

Many thanks Oli
I thought i would have to remove and overboard wall as you suggested, just wanted to check there wasnt another way around it. so i removed and overboarded wall with marmox and green plasterboard, (used the moisture resistant board only at the top of the wall out of the main shower area) if i use a SPF addy i can tile straight onto the marmox but will the green board need any prep.?) also most of you in here mention hardy backer or aquapanel, how do they compare in price to marmox 12.5mm 2400x1200 as i pay £39 +vat per sheet for this, can you get the aforementioned in the large sheets.? if so where from in the Brighton/Hove area.?
once again thanks for a speedy response to you.

 

[sWe]

Welcome to the tilers forums

 

[Fekin]

Hi there and welcome to the forums