Tiling over tiles

[cyclonebri1]

Ok, haven't done a search and I know a similar query will have been posted but can someone advise the best adhesive to use for tiling over glazed tiles with marble tiles on a bathroom wall.
I rendered the "new" wall with sand cement in prep for tiling 15 years ago. All the surface is sound and very flat, for once I made a decent job of the wall and tiling.

Any advice welcomed, cheers

[pete f]

its best to remove existing tiles and re prepare the walls first

[GirlRacerRed]

marble tiles are too heavy to tile on tile. as Pete f says above, remove the existing and start afresh.

[whitebeam]

Marble on existing tiles may be pushing it a bit.

[cyclonebri1]

Well I did think I might be pushing a bit with marble, so point acepted. But the wall is so flat that I'm not going to remove the existing tiles.

So, if I go with a reasonable weight ceramic or even porcelain tile, what's the advice on adhesive??

[pjc]

None what adhesive did you use 15years ago

[robbbin]

Prime the walls first then use a good flexible power adhesive not rapid and dont make addy to stiff that will be fine......

[pjc]

Prime the walls first then use a good flexible power adhesive not rapid and dont make addy to stiff that will be fine......

And what were the original tiles put on with ?

[cyclonebri1]

Well, the tiles were "glued" in place with an industrial epoxy, perks of the then job. Believe me this will not come off without the render, hence my reluctance to attempt to remove it

Yes I was a little industrial in my doings back then, but when it's free

Normally I would automatically remove the old tiles and steam or even replaster, but in this case it would be more trouble than it's worth.

[Del W]

What size and thickness of tile is on the wall now?

[cyclonebri1]

13 x 8 approx, abount 7 mm if I recall

The plot thickens however and swmbo has decreed a new bathroom suite is required, if that is the case then I will strip the lot, which I know is the correct way, but........................

So further to that B&Q have some porcelain mottled marble like tiles on offer. 600 x 600 x 10. Windsor is the range. They don't appear online but they have thewm at our local store.

Now I know B&Q aren't flavour of the month here but has anyone used these?, at £13.98 they appear to be a real bargain. Add to that the wife works for them and on certain days, next Friday being one, she gets 30% discount

[GirlRacerRed]

the only thing I'll say about B&Q tiles (I've used mostly these in my own house cos I like the prices) the sizings leave a lot to be desired. even in the same batches/boxes, some thicker/thinner than others and some not true square. you get what you pay for.

[AustinTiler]

I would grind the glaze off old tile first before doing anything; prime it; then lay with flexible glue

[cyclonebri1]

I would grind the glaze off old tile first before doing anything; prime it; then lay with flexible glue

same thought had crossed my mind but the mess would br greater than removing them. Anyway thanks but irrelevant know, they're coming off.

[cyclonebri1]

Ok, things have moved on but I'll continue in this thread.
I now have the porcelain 60cm x 60cm x 10mm tiles.
Given that I'm likely to have no option but to take this wall back down to the blockwork, what's the recomendation given that I have the tiles to hand. IE, rerender in sand cement, plaster and skim or is it possible to tile direct to the blockwork with some form of thickbed adhesive?

The wall is 100% true to within a couple of mms, the blocks probably being more flat than the existing render.

Best advice and adhesive recomendations anyone.

[jay]

if the blocks are solid with no cracks and true then yes that would be fine is this a shower wall

[Dave Ramsden]

100% no worries, nothing falling off

Rip it off and start again my friend

[jwatson]

if its not flat enough you could dot and dab plaster board onto wall.
DONT skim the plaster board. The board themself will hold more weight than with a scim on it 32kg m2 inc adhesive and grout.( work out the weight per m2 ) for a more secure way use a tile backing board they have far superiour weight load m2.

A common question, how much weight can my wall support, here are the recommended max weight ratings in KG / m2

Plaster Skim on Plaster Board........20KG
Skim and Set Plaster...................28KG
Plaster Board.............................32KG
Sand and Cement.......................40KG
Cement Backer Board..................55KG
Hardibacker Board.......................45KG
Lightweight Tile Backer Board........40KG
Glass Reinforced Cement Sheet.....50KG
Gypsum Fibre Board.....................40KG

Remember to factor in the weight of the tile / m2 AND adhesive and grout
(Some adhesives are manufactured as lighter products).
Grout.........2KG / m2
Adhesive....4KG / m2

grout weight will also depend on how large the tiles are that you are using and the thickness eg a tiled area that uses 300mm tiles will have more grout than an area with 600mm.

[cyclonebri1]

if the blocks are solid with no cracks and true then yes that would be fine is this a shower wall

part of it is, shower over bath

[cyclonebri1]

100% no worries, nothing falling off

Rip it off and start again my friend

Read again Dave, decision already made,

[cyclonebri1]

if its not flat enough you could dot and dab plaster board onto wall.
DONT skim the plaster board. The board themself will hold more weight than with a scim on it 32kg m2 inc adhesive and grout.( work out the weight per m2 ) for a more secure way use a tile backing board they have far superiour weight load m2.

A common question, how much weight can my wall support, here are the recommended max weight ratings in KG / m2

Plaster Skim on Plaster Board........20KG
Skim and Set Plaster...................28KG
Plaster Board.............................32KG
Sand and Cement.......................40KG
Cement Backer Board..................55KG
Hardibacker Board.......................45KG
Lightweight Tile Backer Board........40KG
Glass Reinforced Cement Sheet.....50KG
Gypsum Fibre Board.....................40KG

Remember to factor in the weight of the tile / m2 AND adhesive and grout
(Some adhesives are manufactured as lighter products).
Grout.........2KG / m2
Adhesive....4KG / m2

grout weight will also depend on how large the tiles are that you are using and the thickness eg a tiled area that uses 300mm tiles will have more grout than an area with 600mm.

Ah, excellant info. Tiles are 23kg per 1.1sq mtr so sand cement render would be better for me. If I did use a form of backer board what would be the fixing method, and what adhesive for large porcelain tiles?

[jwatson]

for backer board you could use dry lining adhesive it is strong stuff. or mechanicaly fix them to wall (plug and screw every 300mm2).
the adhesive is just what best you can get in your area (make sure its powder.) the sponser for the forum i think is mapei and they are a very respected adhesive amongst pro's. if you have one near you go into tile giant (sponser of this site) they are always realy helpful and will sort you out.
mapei keraflex is a good one. Tile giant stock mapei products.

[jay]

part of it is, shower over bath

might be worth looking at some sort of waterproofing then