Laying large format ceramic wall tiles

[aspley]

Hi Guys...Some advice pleeeeeeeeeeeeeeeeeease with regard to laying 900 x 300 large format ceramic wall tiles in particular, what preperation is required and what adhesive is recommended.
The location is a bathroom in a new build. The walls are skimmed plasterboard onto which has been applied two coats of Leyland latex matt emmulsion.
Is the fact the walls have been painted an issue?

Thanks for any input

[doug boardley]

the fact that your walls have been skimmed may be an issue. Can you find out the weight per square metre for us Aspley, that way we can advise you more fully!
Doug

[aspley]

I do not have that information to hand Doug but will try and find out 2moz. Is there an issue with the painting of the walls do you know??

[whitebeam]

Sometimes the moisture in the addy can bubble the paint and release it from the walls

[Oli]

You will need to check that the paint is bonded solidly to the wall, get some duck tape and stick it on the wall, leave it overnight and peel it off in the morning, if the paint stays on the wall its ok, if it sticks on the tape and peels off the wall then youll need to remove the paint, use a sander to sand back to the plaster.

Youll need to make sure that the tiles dont exceed 20 kg/m2 taking into account that the adhesive and grout will take up about 4 kg/m2 so the tiles shouldnt be more that 16 kg/m2.

[doug boardley]

being quite large format albeit ceramic and not porcelain, they'll probably be at least 10-12mm thick hence pushing up the weight to past 16kg. There'll probably be 3 in a box Aspley, so jump on your bathroom scales with a box and see what they weigh. If there's 3 in a box it's a little bit less than a m2 but it will give us some idea what they weigh!

[davy_G]

Dont use tubbed gear or it might never dry. Use powdered gear, spf.

[whitebeam]

I'de be using mapei keraflex maxi which will give you a maximum bed of 15mm

[aspley]

If there's 3 in a box it's a little bit less than a m2 but it will give us some idea what they weigh!

Doug.................the box of six weighs 35kg i.e.20kg per metre

[bigandy]

for me your tiles will be too heavy for your skim plaster, esp with the weight of the tiles and adhesive.few options here remove the skim and tile away. remove the plasterboard and re board, possibly using a cement board (they will take more weight) or mechanically fix new boards over the existing into the substrate either battens or wall.but would still be looking at using powdered addy with that weight

[foxman]

I would, also use a flexi adhesive, the right size trowel and even backskim the tiles, probably make the addy a bit more wet, like the guys say though to much weight. just a little tip... if i have to tile onto painted walls ive made a tool by nailing strips of gripper rod onto blocks of wood and scraping over the walls and then a quick and

[garretridge]

i did bathroom a while back and had same issue i chiped the skim of the plaster board with a decorators scraper it come of in nice pieces was able to save the plasterboard took about an hour and then screwed the plasterboard nice and firm primed and tiled perfect job give it a go what have you to loose!

[medlar]

Doug.................the box of six weighs 35kg i.e.20kg per metre

Personall i would re-board with a cement basded backer board mate,i definately would not tile onto the subtrate you have,the weight is a REAL ISSUE for you here

Weight per sq metre (Kg) for 3mm thin bed solid bed adhesive application
Weight per sq metre (Kg) for 6mm thick bed solid bed adhesive application
6mm thick glazed tile
14.26 Kg/m2
18.46 Kg/m2
8mm thick glazed tile
17.62 Kg/m2
21.82 Kg/m2
10mm thick glazed tile
20.97 Kg/m2
25.17 Kg/m2
12mm thick glazed tile
24.32 Kg/m2
28.52 Kg/m2
12mm thick quarry
26.40 Kg/m2
30.06 Kg/m2
10mm thick porcelain
23.88 Kg/m2
28.09 Kg/m2
12mm thick porcelain
27.82 Kg/m2
32.00 Kg/m2
10mm thick natural stone
31.10 Kg/m2
35.30 Kg/m2
12mm thick natural stone
36.48 Kg/m2
40.68 Kg/m2
20mm thick natural stone
58.00 Kg/m2
62.20 Kg/m2

Maximum Permitted Weights

These are maximum permitted weights per m2 of tiles and adhesive combined:

Plaster 20kg/m2
Plasterboard 32kg/m2
Render 40kg/m2
Marmox Tile Backer Board 62kg/m2


Jimmy

[Alan.P]

Not to forget that unplastered board will hold weight per m2 than skimmed / plastered board

Nice post though Jimmy

[medlar]

Not to forget that unplastered board will hold weight per m2 than skimmed / plastered board

Nice post though Jimmy

Alan,
Read the above post again mate ha ha ha, last bit was ratios given,like below here

Plaster 20kg/m2
Plasterboard 32kg/m2
Render 40kg/m2
Marmox Tile Backer Board 62kg/m2

Jimmy

[Alan.P]

Yes mate, I just wanted to point it out to the OP seeing as how he has plasterboard that has been skimmed, it could be an easy mistake to make ( for some ) they might think that they are safe at 32 kg pm2 because they have boards not realising that the skim will bring down their safe working weights.

[medlar]

Nee probs Alan mate he he he

Jimmy