Tiling over floorboards

[James8869]

I’m planning on tiling over 18mm solid wood tongue and groove floorboards. There is a distance of 410mm between the centres of the joists under the floorboards.

I’m trying to keep additional height added to the floor to a minimum, so thinking of using hardie board.

My plan is to bed 6mm hardie board down onto a flexible cement based adhesive, I was thinking this one: https://www.toppstiles.co.uk/trade/.../excel-bond-super-flex-single-part-white-20kg

Then screw down and scrim the hardie board.

Then tile onto the hardie board using that same adhesive.

The kitchen tiles are 60cm by 30cm porcelain.
The bathroom tiles are 60cm by 60cm ceramic.

Would anyone be able to let me know if this sounds like it will work?

Thanks

 

[Wayners]

What's the adhesive online data sheet advise for application over wood?
Also read the Hardie backer data sheet online for application over wood.
Not my area of knowledge so when doing any jobs the data sheets for anything are bedtime reading.

 

[simplesteve]

Speaking as a tiler, I would say you're pretty spot on.
Adhesive wise, I would go for the Topps/Bal Rapidset Flexible, and always buy it in White. Use a 6mm notch Trowel for under the Hardi, and don't forget to prime the floorboards first with SBR. ( don't buy that in Topp s )
Save you fingers by using Turbogold screws from Screwfix.

 

[yorksbuilder]

Yes you are on the right track. I've done this a number of times using 6mm nomoreply, with their mega strength polyurethane adhesive underneath it, and their 25mm self tapping screws. Can use the bal under any parts where the floor may be out of level. Bit if you have the hardi already your plan is sound. Remember to stagger the joints in the backer board and also dont have tile joints exactly above backer board joints if you can help it. All the best

 

[James8869]

Thanks, good to hear I'm on the right track, and I'll prime the floorboard with SBR.

Is it necessary to prime to hardiboard as well prior to tiling over it?

 

[simplesteve]

Nope, rapidset loves to grip cement board - just give it a wipedown with a slightly damp sponge first.