Tiling onto new sand & cement render or tanking

[Deborah]

Can I tile straight onto sand and cement render (with an spr coat) in a shower area? Or does it need tanking?
Am i correct in thinking its better without a finish coat?
Thanks

 

[Qwerty]

Yes you can as long as it is dry. Tanking is highly advisable.

Is it smooth render or rough scratch coat?

 

[Deborah]

Its not done yet so it could be either.

 

[Qwerty]

What surface do you have now then?

 

[Deborah]

blown plaster

 

[Qwerty]

Then it can be removed down to the old render/ block and take it from there. You may be better off removing it all and dry lining with new plasterboard.

What tiles are you planning on using?

 

[Deborah]

Ceramic, brick size tiles.
Apart from the drying time why would dry lining be better?
Some of the render is blown - re-rendering would mean we don't have to hack everything back to brick. If we dry line we'd either have to hack everything back or loose space....

 

[Qwerty]

If it's blown already that indicates a problem. I would personally dry line it as you are guaranteed a strong flat and level surface, peace of mind and it's cheaper, unless of course you are rendering it yourself

 

[Deborah]

Would you take it back to brick? (involves working round a window) or just remove the blown sections?
Would you then tank the shower area?
Many Thanks

 

[Qwerty]

It depends how loose it is and only you will know that. Only the last wet room I did saw what I thought would be a small amount of loose plaster and render turn to this in a few hours!!!.....

Dry lining the whole lot was the only way!......

And Yes, I would advise that you tank the shower area