Is it ok to plaster over old plaster?

[macgrl]

Hello all,

I am re-doing my bathroom and have taken off all the tiles, pretty much 2/3 rds of the room was tiled and will be retiled in the same place. When taking off the tiles some of the plaster underneath came off too so there are patches of bare brick, thin plaster layers and other patches of what seems to be plaster in good condition and not loose. I am planning on re tiling and so the replaster job doesn't need to be perfect but I want to it to be sound.

I am planning on basically filing in the gaps so that the replastered wall is all level and also level with part of the wall above that had no tiles removed and hence that plaster is perfect.

My questions are

i) Do I need to remove the good plaster patches so that I am down to the bare brick all over?

ii) Do I need to coat the brick work and good plaster patches (if they can stay) with a pva mix.

In the pictures you will see that where there is good plaster at the top half of the wall the finishing plaster has been removed as it come off when I took the top half of tiles off (the other tiles below and around the rest of the bathroom where fitted when the house was built and were really set in to the wall hence more of the under plaster came off with the tiles.


pics here - //www.diynot.com/network/macgrl/albums/

I should say and that the pics I have taken are upside down for some reason. So sorry for that... neither myself or the camera were upside down at the time of taking !


Many thanks

macgrl[/img]

 

[Maxsys]

what you do next will depend on the size/type and weight of tiles you propose to put back up.

I would suggest you read the tiling sticky and search the forum for similar threads, this type of question has been answered before.

 

[macgrl]

Thanks so much for your reply.

Looking at it this thread should reallly have gone into the tiling section.

Is is possible to move this thread or should I re post in tiling setion?

Many thanks

 

[Maxsys]

I ma sure admin will move it if you ask them

 

[alexeix]

I'm in a similar situation to the original poster and have searched the forum, but not found the answers I need.

I have a Victorian house and have stripped back the bathroom and removed all the old tiles.

I now want to tile only above the bath, so that I can use it as a shower, but the surface of the old plaster is not particularly good - see attahced photos.

//www.diynot.com/network/alexeix/albums/11438[img]

My builder repaired the larger holes as best he could, but the patches are fairly rough. There are also some smaller holes remaining and I can see other small patches where the original plaster is loose (next to the small holes).
I know that if I start pulling away at it, the whole lot will eventually have to come off...

The tiles I'm going to use are 200mm by 100m, bevelled edged ones from B&Q, called 'Underground'.

My questions are:

1) if I just patch up the existing surface, could I plaster over it and still achieve a good, level finish with my tiles?

2) Are there any products which I could use to cover the area to be tiled, in order to create a level surface and one which the tiles could grip onto, e.g. some kind of sheet? It would have to be quite a thin layer, so that the profile of the edge of the tiles doesn't look too raised.

3) Would I need to seal the plaster, before tiling onto it?

4) I've been advised that the grouting would be unlikely to completely prevent moisture getting through to the wall (hence question 3). Is that true and if so, is there something else I need to do?

Thanks in advance for any advice!