Painted Walls And Prime + Grip

Currently reading:
Painted Walls And Prime + Grip

Search the forum,

Discuss Painted Walls And Prime + Grip in the Australia Tiling Forum area at TilersForums.com.

F

Flintstone

everytime I walk into a room to tile and I see painted walls, I always worry! A lot of the time I've removed any loose with a scraper and scored the rest a bit with Stanley knife, primed with the usual acrylic and tiled with single part flexi and never had an problems.
I've got a job to do next week which some heavy marble tiles and all the walls are painted magnolia, semi gloss, it's a smooth finish and looks to be well on there. Has anyone primed over painted walls with prime + grip to give a good key? I can't remove that paint it's well on there
 
T

Tile Shop

I wouldn't risk leaving the paint on. Seen a few horror stories.

One that I did see done when I was in our showroom, we got a tiler in to convert an old office into a large roomset. White emulsion on a plaster surface. He did a gradual prime coat with BAL APD. diluted (this is very approximate but for old times sake lets just say......) first coat 1:20 and leaving it to soak through the paint, then 1:10, then 1:5. His reason behind it was that this will add an extra bond between the paint and the plaster.

Left it 2 days to dry and tiled it with ceramics..... which was fine cuz they were only around 16kg. not alot could go wrong. But i'd have thought with your mahoosive slabs or rock, no matter how many coats you put on or through the paint, your tiles are effectively only stuck to emulsion.

Its enough to make your bum squeek. Other people may be able to offer a more informed opinion but I'm a little blinkered and can't see past the "tiling onto paint" let alone the "how well is the paint bonded to the surface".

What is the surface under the paint and whats the marble weight per sqm?
 
T

Tile Shop

But now, the paint is the least of your worries. Plaster can only hold 20kg max including the addy. You'll need to speak to the marble supplier to find the weight per sqm.

So if the plaster has to come off too, and providing you don't knacker the plasterboard underneath, that will be able to hold 32kg's. But alot of marble these day is also close to that weight (depending on thickness.... sometimes more)

For the hassle that you'll have getting the paint/plaster off and the risk you're putting into the job by going onto a surface that "may" not be suitable, the safest thing to do would be to rip the lot down and replace it with 12mm Hardie.
 
F

Flintstone

I'm not one for doing something if it's not gonna be safe or have problems down the line. I've used a lot of pretty heavy tiles over the years on all manner of walls and floor, never had any problems, I've not had chance to have a good look at the walls. I know that I have used these same tiles before and had to remove one and it was a real task to get it off, had to cut the plaster board out and re board a small section, there was no chance it was going to fall off.
 
I

Italy

I'm intruding, I when I do work with heavy materials on plasterboard or on painted walls, fixed wire mesh with cadres 50x50mm, (like the one that put in the substrate sand / cement) to the wall and drown in the glue, now I do not know if the thing is feasible in uk, italy in the plasterboard is fixed to steel rail fixed to the wall, I saw that you put behind plasterboard timber. the flow rate may be different.
If you manage to understand what I wrote ...
 
W

White Room

Localtiler said:
I'm not one for doing something if it's not gonna be safe or have problems down the line. I've used a lot of pretty heavy tiles over the years on all manner of walls and floor, never had any problems, I've not had chance to have a good look at the walls. I know that I have used these same tiles before and had to remove one and it was a real task to get it off, had to cut the plaster board out and re board a small section, there was no chance it was going to fall off.
Click to expand...

You asked the initial question about what should I do, you now say it's no problem as I've done it before...the advise given is correct...your choice at the end of the day.

Newly plastered wall and had to take a tile off

Bad Plastering 002.jpg Bad Plastering 007.jpg
 
Chalker

Chalker

TF
Arms
628
1,058
Tadcaster
whitebeam said:
You asked the initial question about what should I do, you now say it's no problem as I've done it before...the advise given is correct...your choice at the end of the day.

Newly plastered wall and had to take a tile off

View attachment 79331 View attachment 79332
Click to expand...

To be fair Mark, that's skim onto skim.
Back to the original question. Plasterboard on its own ! is not a suitable substrate for the job in question. Never mind if it's skimmed and painted.
It's either got to come off, or over boarded with marmox/ wedi type boards or Cement boards like Hardie etc.
 
W

White Room

Chalker said:
To be fair Mark, that's skim onto skim.
Back to the original question. Plasterboard on its own ! is not a suitable substrate for the job in question. Never mind if it's skimmed and painted.
It's either got to come off, or over boarded with marmox/ wedi type boards or Cement boards like Hardie etc.
Click to expand...

I've seen it fall off plasterboard as well and was due to the plaster being mixed to stiff.

The picture above was skimmed but used no pva so it was straight onto old plaster.
 
T

Tile Shop

So still going onto plaster then??? NOOOOOOOO!!!!!!!!!!!!!

Oh well. Good luck. Everyone has tried to warn you of the risk. You'll probably find out in a month how "sound and solid" it really is and I hope to god that no-one is close by when it happens! Thats just dangerous!

Frequently Asked Questions | The Tile Association

Maybe once this job is complete you can apply to re-write Bristish Standards BS5385 as it seems you know better than everyone.

Step back and reconsider....... If anything goes wrong you WILL be liable.
 
T

Tile Shop

Tom Astley said:
Should be OK as very few 600x400 tiles would exceed the weight limit of 20kg psqm for plaster.
Click to expand...

That is soooo wrong. Remember this is marble we are talking about.

Bit of maths for you.......

Most good quality marble tiles of 60x40 are minimum 12mm thick.....

Denisty of solid marble = 2560kg per m3 approx

So a tile 600x400x12 = 7.38 kg's each multiplied by 4.1666 tiles per sqm = 30.75kgs per sqm + 4kg per sqm for the adhesive.

Grand total 35kg per sqm...... Still too heavy
 
5 More Posts...
New posts

Reply to Painted Walls And Prime + Grip in the Australia Tiling Forum area at TilersForums.com

Posting a tiling question to the forum? Post in Tilers' Talk if you are unsure which forum to post in. We'll move it if there's a more suitable forum.

Advertisement

Top