anhydrite floor screed - TilersForums.com

[Chalker]

The biggest mistake here was NOT, heating the floor BEFORE tiling.
even with 6 weeks drying time, his time of year it would not have been dry.

was the screed tested for moisture??

i have made this now to dry our screeds if the boiler can't be commissioned in time for tiling. Can be connected to manifold.

 

[Sean SML Tiling]

That's a great bit of kit there.

 

[Chalker]

That's a great bit of kit there.

Total cost about £700!!
got £250 back in the first job off the builder for hire, as the gas was not going to be connected until a week before customer moved in.

 

[Sean SML Tiling]

Was gonna say I bet it will pay for itself in no time.

 

[Dave]

Just to add to the comments already posted , cement based adhesive is fine on these screeds if the screed is dried and primed correctly , so NO ! You will not always get a reaction with cement adhesive to calcium sulphate screeds .. You get a reaction if there's still moisture or it's not prepped properly ..

As as for your situation , then the screed should have been commissioned before tiling commenced and your tiler should have known this.

But and this is a problem also caused by the plumber just whacking on the heating , that is ludicrous ... If he had turned it on very low and increased it in small amounts , then as long as the floor was dry to start with , I think your tiles would have stayed down... Anhydrite screeds are stronger than a cement based screed and not prone to cracking like a cement screed does when first heating them , hence why a heated floor should be commissioned first as all heated screeds should be really but you might have been fine heating slowly as I said , the argument is , was the screed dry and was the plumber notified that the heating should be increased slowly ?...

not it a good situation to be in but it does seem the fault could lay with both the tiler and the plumber.

 

[Just Rizzle]

I disagree with dave no one these days should be mixing. theres plenty of products out there there that are compatable with the appropriate substrates. you wouldn't mix crossply tires with radials on your car, so why use cement based adhesives on anhydrite its a no brainer . like for like every time

 

[barno101]

Cheers for the info Dave ,, Ive got a meeting in the morning with both the plumber and tiler to get to the bottom of this ,,and I don't want to pass blame on any one of them ,but I need to get to a decision as to whether it is the floor being damp ,,or the heating being put on too quick too high temperature ,, at the end of the day the tiles have to be replaced and somebody has to pay for this ,,, if it was a small area say 20 to 30 m2 I would pay myself but this is a big area
Cheers

 

[Dave]

I disagree with dave no one these days should be mixing. theres plenty of products out there there that are compatable with the appropriate substrates. you wouldn't mix crossply tires with radials on your car, so why use cement based adhesives on anhydrite its a no brainer . like for like every time

Can I ask what you used before gypsum adhesives ray ?


yes I agree with gypsum to gypsum now we have the choice , just your statement on cement based adhesives was incorrect. Imo ..

 

[barno101]

Just an update ,,
Had a meeting with Tiler and Plumber ,and after a few strong words from all parties involved ,,we came to a decision, that they were both at fault and we have decided to ,,all of us put it right and retile the area ...
Tiler for not checking dampness ,, plumber for whacking the heating on to high ( and leaving it on for 5 days )..
Thanks again for all your comments

 

[Stef]

Glad you got a satisfactory outcome & the plumber & tiler have learned something new..