need help

[geehutch]

can anyone tell me why i cant get ditra 25 to stick to the adhesive. using granfix 1 part flexible fastset which schluter say is fine. granfix told me to prime floor with their acrylic bonding and mix adhesive with flexi additive. have tried this using different consistencies and every test patch i have done i can pull matting up with no effort. fleece is covered in adhesive when stuck down but just doesnt get a secure bond. fix has good hold of floor. have 90m of this stuff but feel like dumping and just sticking tiles directly to concrete floor, which has wet underfloor heating which has been off for 3 weeks now. any advice gratefully recieved. thanks. geehutch

 

[Ian]

How long are you leaving the adhesive to set before pulling the mat up?

 

[geehutch]

Overnight, thought this should be long enough for fastset. Mat fully bedded in, you can see a perfect impression of fleece and squares of top surface when lifted up. Never having used before dont know how well mat needs to be stuck down but would have thought it should be difficult to remove from the cured adhesive. Thanks for reply

 

[White Room]

The adhesive probably takes about 2 weeks to fully cure....

 

[CJ]

Flexi addy WITH flexi additive? That'll be like working with chewing gum??

 

[salmonfisher]

Do test patch with a tile on it - bet you cant peal it of after that

 

[Mr Tiler]

The adhesive probably takes about 2 weeks to fully cure....

So how long is matting left before tiling? Cheers

 

[White Room]

I usually fix on Ditra the next day....but it can have tiles fixed the same day.

 

[geehutch]

So, found today i have wrong additive. Should have bought Granflex plus, which is for adding to modified addy and will make make my C2 up to an S2. Question is Granflex plus will cost same or more than some S2 bags , and if i buy new stuff i will still have the granfix stuff for my wall tiling etc. So can anyone recomend fix that will stick down my Ditra and if it doesnt do that at least it will be the proper spec stuff to stick my 600 x 600 porcelain directly to my underfloor heated sand/cement screed. thanks and merry Christmas to all ????

 

[geehutch]

what is worrying me is if matt not properly set in it will pull up when i lift a tile to check coverage, add more addy to level tile etc. I'm in enough mess already without that. if experience is indeed the name we give our mistakes then i am becoming very experienced doing this job. ho ho ho

 

[White Room]

I use S1's for most things, sticking Ditra down and fixing porcelain to Ditra....

 

[charlie1]

I'll be honest, I've never used ditra but I think your worrying too much, it's so easy to fabricate problems in your mind that don't and never will exists in tiling... I've learned this over the years.... You will give yourself an early grave man, it will be ok!

 

[Sean Kelly]

I fix Ditra or Durabase with rapid or slow flex. Then leave it overnight and tile on it the next day. If you try and tile on it straight away then you will have to walk on the mat before the adhesive has time to dry - you will break the bond and the mat will never stick to the substrate. Also, as you have already said, you will pull the mat away from the substrate if you have to lift a tile.

 

[Mr Tiler]

I'll be honest, I've never used ditra but I think your worrying too much, it's so easy to fabricate problems in your mind that don't and never will exists in tiling... I've learned this over the years.... You will give yourself an early grave man, it will be ok!

I think tiling feels so delicate when you first start... I was scared and am still cautious of stepping on rapid 'setted' tiles after a few hours. But there solid and there is no moving them unless you have done something wrong and to my satisfaction accept a bit of lippage I haven't made fundamental mistakes and the knowledge I have gained from the seasoned experts on here my tiling will always be at the least, safe. I do however feel sometimes they can be a bit overly cautious and critical... But that is what British standards are, its so you never have a problem for years to come. Merry Christmas!

 

[Dougs Third Go]

S1 C2, addy is my recommendation, how long and what depth has the concrete floor been down for,? also has ufh been commissioned yet?

 

[Time's Ran Out]

Most of the replies you've received would only confirm my thoughts that the 90 mts of tiling you have should be undertaken by a professional.
Check out the adhesive poll and see where Granfix comes!

 

[geehutch]

S1 C2, addy is my recommendation, how long and what depth has the concrete floor been down for,? also has ufh been commissioned yet?

floor been down 2 years, 70mm thick sand n cement, heating been on about 3 months and commissioned, switched heating off a couple days before attempting to stick mat