Tiling on Weyroc Protect

[alan42]

Hi

I have to tile 3 X new build upstair floors each comprising a bathroom (6 sm) and en-suite (3 sm). The existing floor is a product called Weyroc Protect which is 22mm flooring grade chipboard with "resin impregnated Kraft paper on both sides of the board providing double protection and preventing moisture ingress". The boards are screwed directly onto 195mm X 75mm joists and are pretty stable. The rooms will also be laid with loose cable electric undertile heating. The tiles in the bathroom are 66cmX33cm porcelain, and in the ensuite 33cmX33cm ceramic approx 10-12mm thick. Knowing it's recommended not to tile directly on chipboard, I contacted Weyroc for advice, who unsurprisingly extolled the virtues of their product being one of the few that can be tiled directly onto and sent me names of recommended adhesives. The problem is I phoned the adhesive companies who each had doubts about the suitability of their own product in this situation. The adhesives were:

• Ardex 7001. They thought there would not be sufficient adhesion as the chipboard had some sort of covering, so would not guarantee it would work. Also heard from one of their stockists that this is not the most flexible adhesive.
• Biscem Vitri-Flex. They were worried about insufficient flexibility of the adhesive over the floor made worse by using UFH, so potential for both lateral and vertical movement. Also by using larger tiles in the bathroom there are fewer grout lines to take up any flex.

I also have the part of downstairs to tile, but there the floors are flooring grade chipboard approx 16 sm in each house, and no UFH. I know it's an option to use a backer board, but same drawback as most find - it raises the height.

Has anyone experience of tiling over Weyroc Protect. Also what about using latex SLC to cover the UFH and then tiling over using a reasonable flexi adhesive. Would the SLC bond sufficiently to the floor. Last question what is best option to tile onto the dowstairs chipboard without overboarding.

Appreciate any help.

Alan

 

[grumpygrouter]

Ardex 7001 would do the job IMO but you are better to overboard with 6mm hardie or similar. If you want something really flexible try mapei keraquick with latexplus additive. Never heard of the weyroc product you hve mentioned but not sure that tiling onto an "adhered" coating is really the answer though!

 

[DHTiling]

Personally i would over board...Hardibacker 250(6mm) would be my choice..much better product to tile too and no adhesion problems.

 

[Stephen@Weber]

Even if you did use SLC (I would go for a fibre one) it would have to be 10mm thick to give it the strength you need. Wedi have just released a backer board that they will guarantee that is 4mm thick, it has to be stuck down with a single part adhesive and have 5 screws in every square metre, might be your option that gives the least extra height.

 

[doug boardley]

deffo go down the hardiebacker route if it was my job

 

[Richard Edwards]

Alan

Is the bond of the ' Kraft paper ' really really strong and can you delaminate it with tools / knife / ripping etc. I'm not familiar with Weyrock Protect.

I might be able to advise you a product that will do the job without backerboard etc but it is seriously expensive. It all hinges on the security of the paper bond to the Weyroc
:dizzy2::dizzy2::dizzy2:

 

[Aston]

hi alan

as the boys have said, overboard with 6mm hardibacker and you then have a stable reliable surface to tile onto and it wont break the bank

 

[Scott]

I googled the weyroc, its a p5 grade chipboard with a water protected coating. IT is slightly stronger than standard p5 but not a lot. As for whether you will get the tiles to stick to it, it does have a no slip coating ont eh surface sso should therefore have some kind of key to it. However all said it backer over the top anyway. Its only 6mm on the height.

 

[doug boardley]

is this the stuff Alan? if so, I stand by my previous post

 

[DHTiling]

I don't really care what the chipboard is covered in, it is still chipboard... compressed chippings!!! and not really stable to tile too directly, so a deffo overboard IMO..

 

[alan42]

Thanks to all. Certainly gives me an idea what the general consensus is. By the way I contacted BAL as their fast-flex 2 part was since recommended. They said it is suitable for tiling directly on Weyroc/chipboard and with UFH. So it's down to that vs Hardie backer from a cost and extra work aspect.

Alan

 

[doug boardley]

it's your call alan, but tilers with a lot of years experience have said not to do it...

 

[kitl]

Hi I am new here, this thread is very relevant as my builder has just put down weyroc insisting it is fine to tile on and the first tiler I approached wants it ripped up!
Is Hardibacker suitable for UFH? I have pipes in screed between joists.

Thanks for any help.
Kit

 

[Time's Ran Out]

:welcome:Kit - Your floor sounds as though its a 'floating' floor and has its own set of problems/drawbacks!
You may find in this case that your tiler is correct, but there are other issues with reference to movement and stability and deflection of the surface which need to be checked.
A consensus on the forum would undoutably ascertain the unsuitability of this type of substrate for tiling, however Adhesive manufacturers do make products for 'floating' floors but the ultimate decision would rest in the contractor (tiler) accepting responsibility for future movement/or not!

Advice : post another thread with your particular situation and assess the replies.

 

[kitl]

Thanks John
It is a suspended rather than floating floor and the original boarding was removed so that the ufh pipes and screed(pug) could be installed. Most is now ready for re coverin but some has been freshly Weyrocced. The rest is still screed and joists.
Do I have to remove the weyroc and replace with ply? Is 12mm ply ok?
I am concerned about the heat transfer.

Thanks in advance

Kit