Help!: Advice needed

[pjcm]

I have a 6 square metre utility room floor to tile with 340mm x 340mm porcelain tiles. The floor is relatively new and is 22mm weyroc chipboard, it is level, good condition and has no deflection at all.

I have been advised I can use Bal single part fastflex using a tipped trowel straight onto the chipboard no need to overlay with WBP.

Or use Toppfix adhesive superflex 2 part flexible (a lot cheaper) straight onto the chipboard no need to overlay with WBP.

I have 18-20mm depth from floor to threshold, the utility room incorporates a sink, tumble drier and washing machine which dances around when on the spin cycle. I am wondering which option to go with. I would usually go that extra mile to make sure a job does not fail.

Your feedback on this would be much appreciated. Thanks in advance Paul

[timeless john]

Paul - I would never tile directly onto chipboard.

Look at the adhesive manufacturers fixing instructions for timber floors, and go with the most appropriate adhesive for your choice of tile after you have overboarded - IMO with a cement backer board or similar - if you are confident of no deflection.

I have seen on many occasions tiling direct to chipboard and within a short period of time water ingress has blown the floor or cracking along every joint.

Prepare to succeed.

[YourTiler]

Hi Paul
I have used the Toppfix adhesive superflex 2 part flexible ( what a weird thing this stuff is ) on chipboard because the customer didn't want his floor to go any higher than it was, obviously except for the tile
Despite all my reasons as to why not he was adamant.
Anyway that was about 16 months ago. Not heard anything back, and believe me, I would have
You have to make sure that you leave nowhere for water to seep through (as said above) once the chipboard blows it's game over
Sometimes you do as asked, sometimes you walk away

[Bri]

As Timeless john says overboard with a cement board if you have the height to play with. Water will find a way through to the substrate if the washing machine or sink leak. The floor will stand a much higher chance of surviving if you use this method as opposed to tiling directly to the chipboard.

[waterfd]

Some chipboards react to adhesives and if there is a height problem with overboarding I would lay Ditra over the whole floor using Ardex AF200. This would protect against water ingess to the chipboard as well as acting as a decoupler.

[pjcm]

Thanks to everyone that replied, I am now going with the overlay.

cheers Paul