Need a bit of building advice
Discussion
A plastering/rendering question.
I'm planning to put some heavy (32kg/m2) 12mm travertine tiles onto existing tiling. I thought the old tiles were well stuck but on closer inspection about a third of them aren't, and the plaster underneath (on breezeblock) is very soft in places.
My first thought is to chip away the loose tiles and soft plaster, then make good with cement to give me a flat surface for the new tiles. However, I don't want to take any chances! Can any PH builders tell me the best thing to do please?
I'm planning to put some heavy (32kg/m2) 12mm travertine tiles onto existing tiling. I thought the old tiles were well stuck but on closer inspection about a third of them aren't, and the plaster underneath (on breezeblock) is very soft in places.
My first thought is to chip away the loose tiles and soft plaster, then make good with cement to give me a flat surface for the new tiles. However, I don't want to take any chances! Can any PH builders tell me the best thing to do please?
You'll need to remove all the suspect tiles and plaster. In fact, remove all the tiles anyway. Replaster and then retile.
If you're going to plaster over existing tiles or paint, use Thistle Bond-it to prime. It comes in 10ltr tubs and is not cheap, but it does work. Make sure you keep mixing or the sand binder will sink to the bottom of the tub.
Just used it on artex at home, and it seems to be working a treat, after the first lot (primed with PVA) fell off the wall in one big sheet. Never known that to happen in 26 years in the industry. Who says you never stop learning?
maggit
If you're going to plaster over existing tiles or paint, use Thistle Bond-it to prime. It comes in 10ltr tubs and is not cheap, but it does work. Make sure you keep mixing or the sand binder will sink to the bottom of the tub.
Just used it on artex at home, and it seems to be working a treat, after the first lot (primed with PVA) fell off the wall in one big sheet. Never known that to happen in 26 years in the industry. Who says you never stop learning?
maggit
mrmaggit said:
You'll need to remove all the suspect tiles and plaster. In fact, remove all the tiles anyway. Replaster and then retile.
I think you're right. I don't want to take any short cuts with 3/4 ton of travertine!
mrmaggit said:
If you're going to plaster over existing tiles or paint, use Thistle Bond-it to prime.
No, my plan is to keep any good tiles as a height guide and simply plaster up until all is level. Do I need to use any primer on the bare exposed old plaster?
mrmaggit said:
Just used it on artex at home, and it seems to be working a treat, after the first lot (primed with PVA) fell off the wall in one big sheet. Never known that to happen in 26 years in the industry.
I read on the Screwfix forum that PVA can stop the adhesive getting a grip on the substrate
simpo two said:
You'll need to remove all the suspect tiles and plaster. In fact, remove all the tiles anyway. Replaster and then retile.
I think you're right. I don't want to take any short cuts with 3/4 ton of travertine!
Strewth, How big is the room?
mrmaggit said:
If you're going to plaster over existing tiles or paint, use Thistle Bond-it to prime.
No, my plan is to keep any good tiles as a height guide and simply plaster up until all is level. Do I need to use any primer on the bare exposed old plaster?
No, so long as it's sound and not flaking.
mrmaggit said:
Just used it on artex at home, and it seems to be working a treat, after the first lot (primed with PVA) fell off the wall in one big sheet. Never known that to happen in 26 years in the industry.
I read on the Screwfix forum that PVA can stop the adhesive getting a grip on the substrate
PVA is an adhesive/primer that has been used for such for donkeys years. I suspect the problem is more the lack of porosity of the Artex, or Lorraines' dad being a bit over liberal with the wallpaper paste on the wall.
simpo two said:
I read on the Screwfix forum that PVA can stop the adhesive getting a grip on the substrate
IIRC it depends on the adhesive. Some recommend using PVA as a sealant, some dont. Apparently it's due to moisture getting into the PVA & it losing some grip. It's been fine for out tiles, but they aren't travatine!
bga said:
I read on the Screwfix forum that PVA can stop the adhesive getting a grip on the substrate
IIRC it depends on the adhesive. Some recommend using PVA as a sealant, some dont. Apparently it's due to moisture getting into the PVA & it losing some grip. It's been fine for out tiles, but they aren't travatine!
PVA is water soluble, and as such, will break down if in contact with water for a period of time. If this is likely, you should be using SBR.
Incorrigible said:
If so where did you get them from... Best price I've found so far for a filled travertine is £22 a metre
B&Q had a deal on 600x400 tiles but sold out. However I got really nice 400x400 tiles - which actually I prefer - from Colchester Tile Centre for £29/m2. Nice light colour and good pattern; I don't like the darker blotchy stuff. Very helpful folk too, and free delivery.
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