tanking straight onto bond coat

[aflemi]

Why did he use bonding, hardwall would have been better i know it is being tanked but i dont like bonding in any wet situation it just seems to attract moisture from the air and stay damp.
Andy

The situation was that the enclosed (3 walls) shower area was previously fully tiled on solid plastered walls. I removed the tiles and scraped off old adhesive. In doing this then some of the finished surface below was bound to come off, leaving up to 3-4mill diffirence on surface levels. Also there were gaps up to 25mil deep back to blockworkjust above the shower tray where it had been shoe'd in. I asked the plasterer to do a levelling bonding coat, then, on the advice above, a finishing skim. Apart from right at the base the bonding would have been no more than 4-5mil thick, I also think he filled the really deep gaps with a quick drying filler. I would have put backing boards all round but didn't have the room to increase wall depth or shower door would then have been too wide.
What better alternatives would I have had please?
Also in light of the above extra info on depth of plaster applied, how long do I leave before tanking?
Again many thanks for input, very useful.....

 

[grumpygrouter]

The situation was that the enclosed (3 walls) shower area was previously fully tiled on solid plastered walls. I removed the tiles and scraped off old adhesive. In doing this then some of the finished surface below was bound to come off, leaving up to 3-4mill diffirence on surface levels. Also there were gaps up to 25mil deep back to blockworkjust above the shower tray where it had been shoe'd in. I asked the plasterer to do a levelling bonding coat, then, on the advice above, a finishing skim. Apart from right at the base the bonding would have been no more than 4-5mil thick, I also think he filled the really deep gaps with a quick drying filler. I would have put backing boards all round but didn't have the room to increase wall depth or shower door would then have been too wide.
What better alternatives would I have had please?
Also in light of the above extra info on depth of plaster applied, how long do I leave before tanking?
Again many thanks for input, very useful.....

Generally allow 24hrs/mm thickness of plaster. it is not just the drying that you need to look out for. The plaster can appear "dry" but it will not have reached full strength. It needs to be as strong as it will get to support your tiles.

 

[aflemi]

Thanks, Grumpy. Also on the alternatives... If I can avoid getting a plasterer in, I would like to know alternatives for future in a similar situation, apart from backer board, obviously.
Many thanks again.

 

[lucius]

Now you have explained it their is not much more you could have done other than hacking every thing back to the render and doing it again in sand and cement but this would very much depend on the strength of the render and what kind of blocks it was on and maybe a bit over the top.The only thing differrent i may have done would be to have used one coat plaster as it would been done in one hit.It is always better to put finish on top of bonding the same day as if it drys out the finish tends to bubble in this situation most plasteres would unibond first but here in a potentialy damp situation i would SBR just to be sure.
Andy

 

[aflemi]

Great, I'm sure that's the first step on the tanking procedure, thanks.
Also thanks to everyone for their input.

 

[davy_G]

Thanks, Grumpy. Also on the alternatives... If I can avoid getting a plasterer in, I would like to know alternatives for future in a similar situation, apart from backer board, obviously.
Many thanks again.

Turn your tilers trowl round and skim it yourself with rapid set.
Tile in 3 hrs, no one else needed. Bingo.:hurray:

 

[Dan]

Just bumping some of the older popular (sometimes not so popular) threads. Probably wont be current discussion these days but I just need to do it. So just ignore the thread if it's not current for you.