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

 

[Richard Edwards]

Hello Kitl and welcome.

A quick question - is the floor on the ground or 1st / 2nd floor etc and are the joists timber or concrete beams. I assume the UFH is water type. As John has sai we need a bit more info / picture or two to move this forward.

Deflection and movement of the substrate is always a major issue. If this is the case then an Uncoupling membrane on top of any sheet material that you use might be answer.

Please post your additional info and the members on here will help.

 

[kitl]

Thanks Richard
The floor is timber joist ground floor with a void underneath. The ufh is water.

 

[grumpygrouter]

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

Next time your builder tries to tell you what is fine to tile onto, casually mention that your glazier recommends holding his brickwork together with putty! After all, it holds his glass in place ok.................:smilewinkgrin::smilewinkgrin:

 

[lent]

Have just moved into a house where the porcelain flooring has failed...tiles are blown. Substrate appears to be Weyroc Protect.No idea which adhesive was used. kitchen has been flooded though exposed Weyroc,under the units, does not seem to have been adversely affected. Nevertheless its made me a little nervous about this stuff,as I am about to quote for relaying these tiles and by coincidence the same board is on another job i am also about to quote for.
I phoned the company www.egger.co.uk who reccomended bal flex and fast flex,Ardexflex 7001,and Biscem vitreflex (Bostic). I just like 'ALAN 42' am calling adhesive companies for confirmation

 

[Richard Edwards]

Have just moved into a house where the porcelain flooring has failed...tiles are blown. Substrate appears to be Weyroc Protect.No idea which adhesive was used. kitchen has been flooded though exposed Weyroc,under the units, does not seem to have been adversely affected. Nevertheless its made me a little nervous about this stuff,as I am about to quote for relaying these tiles and by coincidence the same board is on another job i am also about to quote for.
I phoned the company www.egger.co.uk who reccomended bal flex and fast flex,Ardexflex 7001,and Biscem vitreflex (Bostic). I just like 'ALAN 42' am calling adhesive companies for confirmation

Hi Lent

Well I guess you have read through this post start to finish and basically nothing much has changed.

If you want to keep the Weyroc - not sure why you would want to, however,,,, Replace any boards that have swollen or been water damaged. Ensure entire floor and supporting structure is sound, stable and well screwed down etc.

Then if you can, overlay with a suitable board, hardibacker 6mm , lux 6mm or similar cementous board - this will need to be layed with flexible ady and / or screwed depending on the board selection.

If you cannot accept the increase in height [kitchen units for example] Then there is only one product I can put my name and recommendation to - [only because I have never used the others - not to say they aren't suitable, they might be] BAL FASTFLEX.

Its very expensive, works out at about £45 GBP for 2-2.5m2 is not easy to use and you need to work very clean and tidy, especially the grout joints as the cured product dries to a charcoal colour and sticks to literally everything it touches. But we use it a lot and we price timber floors with it and in 8 years of using it I have never had a failure. But I repeat - the floor must have no noticeable deflection under normal operation loading. [Three fat ladies jumping up and down on 1 m2 is about right ]

Hope this helps

 

[lent]

Hi

have now called Ardex who seem a bit nervous despite weyroc having written confirmation that ardex 7001 is suitable.
Biscem not available in my backwater.
Bal without hesitation recommended SINGLE PART Balflex

 

[lent]

also keep in mind that the boards must be glued together with a water repellant adhesive,and sealed on the edges.