When Do You Uncouple?

[Stef]

That gypsum based adhesive scares me too impish!.....don't mind laying the decoupling membrane with it ( Bal rapid mat mostly ) then flexi cement based addy

I've done a few gypsum floors & give me them any day over a cement screed.
Anhyfix for adhesive & as long as all rules are followed then there's nothing to be worried about.

 

[MW Smith Ceramics]

I've done a few gypsum floors & give me them any day over a cement screed.
Anhyfix for adhesive & as long as all rules are followed then there's nothing to be worried about.[/QUOTE

I've done a few gypsum floors & give me them any day over a cement screed.
Anhyfix for adhesive & as long as all rules are followed then there's nothing to be worried about.[/QUOTE

Are gypsum based adhesives recommended with British standards??.....I'm sure even if it comes to annhy screeds then British standards recommend priming then cement base addy

Can any of you technical gurus confirm???

 

[Stef]

I'm not sure what British standards state but why take the chance of putting cement in contact with gypsum when they are not compatible unless you create a barrier between the 2?

 

[MW Smith Ceramics]

Totally see where you are coming from there Stef........it just baffles me why gypsum based adhesives are not mentioned within British standards regarding tiling onto gypsum screeds, so you have Ardex, Bal & Mapei that all recommend priming then using cement based addy and this is British standards they follow, so regarding gypsum based adhesive who makes the rules

 

[White Room]

Totally see where you are coming from there Stef........it just baffles me why gypsum based adhesives are not mentioned within British standards regarding tiling onto gypsum screeds, so you have Ardex, Bal & Mapei that all recommend priming then using cement based addy and this is British standards they follow, so regarding gypsum based adhesive who makes the rules

They probably haven't caught up yet or haven't a clue about usage of it....

 

[Stef]

They probably haven't caught up yet or haven't a clue about usage of it....

Probably don't know about it.
I've only done one anhydrite floor with a cement addy, I gave it 4 or 5 coats of primer & im still paranoid about it.
It's still stuck solid but I wouldn't just rely on 1 or 2 coats of primer as manufacturers state as I don't think your creating that barrier between the 2.
Anhyfix is a superb addy & sticks like the proverbial.

 

[Flintstone]

I struggle to see the use of uncoupling unless your perhaps using fragile stone tiles. As said by some one else, I wouldn't feel happy laying it over floorboards when you could board it instead which would probably take a fraction longer to do

 

[One Day]

But if you don't need to add strength, and only need protection from lateral stress, why bother over-boarding?

 

[Stef]

Good discussion from both sides.
I've started using more thermal boards than Hardie as the foam in the boards will slightly decouple the substrate, this is only my view don't take it as gospel,
I used Ditra on caberdeck flooring & had problems with a bit of grout cracking, Ditra fixed with af200, I couldn't overboard as we were tight to the front door.
In America they overboard with OSB then fix Ditra to everything.

 

[J Sid]

I struggle to see the use of uncoupling unless your perhaps using fragile stone tiles. As said by some one else, I wouldn't feel happy laying it over floorboards when you could board it instead which would probably take a fraction longer to do

I have in the past laid no more ply over boards and had It fail, the boards cracked along some of the wood joints..... Hence I use membrane now.
I would add I feel HB is a better product than NMP and prefer the fixing method for HB, feel it gives a stronger finished floor.

 

[Dhtiling]

Here where I live everything is wood subfloor, so most everything gets a membrane. If a floor needs added strength we do that with plywood then a membrane. Ditra or any other product is nice because it is lightweight so easier on the body to install. Are membranes overkill in most cases, sure, but people who call for work have seen the marketing and ask for it usually.

 

[Flintstone]

A high amount of regular Joe blogs customers aren't over the moon about the cost of boarding never mind adding a mat on top. Would probably loose loads of jobs if I insisted on both of those things. Boarding for me bridges all joints in floor boards etc with something solid.

 

[One Day]

If a potential customer won't listen to and accept my advice on how a job should be done, then they never make it to 'customer' stage. Why bother if they won't play it your way?

 

[Flintstone]

I agree with you totally. I was referring a bit to dhtiling saying he puts a mat on every wooden floor. - no need.

 

[Flintstone]

I'd like to know how there can be lateral movement in nmp boards glued together