plaster comes off when i remove the tiles

[noobtilegirl]

Hi

I have just started to remove the tiles on my bathroom wall. The walls are solid walls but have been plastered (not plasterboard). As i am removing them, the plaster is coming off at the same time.

Do i need to replaster the wall before putting the new tiles on? or can i grout straight onto the concrete wall?

If i do need to re-plaster, how long do i need to leave the plaster to dry? i read somewhere that i need to leave it for a month, but i was planning to reapply the tiles in three weeks time.

thanks

[Bri]

Welcome to the forum. You say underneath the plaster is the concrete wall, is this brick/breeze block or a plaster bonding (bonding is used before a skim of finishing plaster is applied, sorry if you already know this!) and what type/size will your new tiles be?

[whitebeam]

As above, also is it about 2-3mm finish coming away from a hard cement/render, if you see what I mean.

[Bri]

As above, also is it about 2-3mm finish coming away from a hard cement/render, if you see what I mean.

Yeah that's what I was trying to get at!!!!!!!!!! Thats what it sounds like, the skim coat is coming away with the old tiles. Hopefully we'll find out soon

[noobtilegirl]

hi

I cant see the breeze block, so i am assuming what is left is the plaster bonding you mention above.

Thanks v. much for everyones help and comments so far.

[Bri]

You will need to repair where the skim has come off the bonding, as bonding is not suitable to tile directly to. What size/type are your new tiles just so we can make sure that they aren't too heavy to go onto skimmed walls.

[whitebeam]

To determine what backing for the finish plaster which is coming away, get an old screw driver and try to dig into the backing coat, if it's tough and won't damage, then it's odds on sand/cement.

If it digs in then it would be a gypsum backing..

You don't state what area your from.

[noobtilegirl]

Ok thanks for the responses - sounds like a little more work than I first thought. The new tiles are about the same size as the ones I'm replacing so hopefully should be ok for the wall.

[johnfrench10]

Hi noobtilegirl

Sorry to hijack your thread but I had a similar problem. My external wall had about an inch thick of bonding plaster which was very loose in places and just fell off. I removed all the loose stuff and evened it up with a 'one coat' plaster from Wickes although I built it up in a few layers.

The finish is far from smooth but it is flat and the 'one coat' dries much harder than the bonding plaster. My question was to Bri........can I tile straight on to the 'one coat' plaster which claims it is suitable for decoration or does it need a skim? I am only using 150 mm x 150 mm ceramic tiles.

Thanks

[Dave]

Yes you can... I use wickes one coat as well.. dries very hard.. and is a stable background for tiling to.

[johnfrench10]

Thanks Dave

Does the one coat need priming with SBR before tiling?

[Dave]

yes.. either sbr 3:1 or acrylic primer..

[harold]

Sorry to jump onto thread.

I'm on a job where the finish coat is coming off in places and leaving bonding coat on which seems solid enough. Can i patch up this with wickes 1 coat after sealing with sbr? Also where bath has been removed the walls under bath are bare breeze block. Can i use 1 coat to plaster this and then tile straight onto it saving time for drying out.

How long does wickes one coat need to dry for? Is it 4 weeks as other plaster recommends?

Thanks in advance

[Sir Ramic]

Yes use one coat plaster for replacing the skim but why not use plasterboard where the bath was ??

[Lincoln-tiler]

Or better yet, board the whole wall. Nice fresh wall, quick easy and not that expensive

[harold]

Can't board wall cos it would bring finish surface out too far upto rest of wall. Don't really want to start taking off rest of plaster back to breeze block.

How long would this need to dry out for. Its prob only up to 10mm thick?