Tanking Alpha Hemi Hydrate Screed - Tile Advice

[hmtiling]

Hi all. I've got a wetroom to do with a pumped screed floor and wondering what would be the best method of tanking it. The floor has wet ufh and using silver trav.
Thanks in advance.

 

[hmtiling]

Please don't say Tilesafe

 

[Ajax123]

Same as you would tank any screed. It needs to be dry, sanded, clean and the ufh commissioned and run. Alpha hemi is a type of gypsum based screed.

 

[hmtiling]

Same as you would tank any screed. It needs to be dry, sanded, clean and the ufh commissioned and run. Alpha hemi is a type of gypsum based screed.

Thanks for that.

 

[hmtiling]

I'm imagining that as it's being tanked then cement based adhesive is fine?

 

[Dave]

Same as you would tank any screed. It needs to be dry, sanded, clean and the ufh commissioned and run. Alpha hemi is a type of gypsum based screed.

Evening Alan , might be a membrane tanking method..? And not paste..

 

[Ian]

Funnily enough, I've just done one. Used ditra on the floor and liquid on the walls as they were plasterboard.

 

[hmtiling]

Evening Alan , might be a membrane tanking method..? And not paste..

I was hoping to use a compound and tapes. The tiling is following on into a hallway and another couple of rooms and want to avoid raising the level if possible.

 

[hmtiling]

Funnily enough, I've just done one. Used ditra on the floor and liquid on the walls as they were plasterboard.

Are the tanking compounds not compatible with gypsum screeds?

 

[hmtiling]

Are the tanking compounds not compatible with gypsum screeds?

I know I should be using ditra with the stone anyway but the client won't pay for it. He's agreed to take the risk and put it in writing.

 

[Ajax123]

I know I should be using ditra with the stone anyway but the client won't pay for it. He's agreed to take the risk and put it in writing.

That's a loser straight away. If it fails you should be liable regardless of waiver as British Standard say uncouple with natural stone.

Any membranes that are compatible with cement will be OK with gypsum. It's what you stick em on with that matters. I'm not aware of any that are not compatible. I personally prefer liquid tanking.

 

[hmtiling]

That's a loser straight away. If it fails you should be liable regardless of waiver as British Standard say uncouple with natural stone.

Any membranes that are compatible with cement will be OK with gypsum. It's what you stick em on with that matters. I'm not aware of any that are not compatible. I personally prefer liquid tanking.

I'm a lastogum fan myself but never used it on gypsum screeds. It's obviously suitable for plastered/skimmed walls but still wasn't sure about the floor.
I didn't realise I'd be liable with a waiver in place. The reason he won't budge is he's had a 50m2 floor with same screed ave stone done 5 years ago without any problems. I had a good look and there's not a hint of a hairline crack. Unsure whether to commit now!