Tiling Question

I am tiling my bathroom floor. what plywood? what adhesive to put on underfloor heating?

i am tiling my bathroom floor. I am planning on putting 15mm plywood down, then devi underfloor heating, then putting ceramic tiles on top...Does the ply need to be wpb? can i put tile adhesive straight onto the underfloor heating? if i can what is the best adhesive to use?

5 Answers

Best Answer

Hello Margaret.
Normally i would rip up the existing floor boards and lay 18mm WBP plywood. then work from there. because the finish tile would be the same height as the carpet meeting the tiles at the door threshold.
If you are overlaying onto existing floorboards. Screw your boards down, then you could overlay 9mm WBP ply then your underfloor heating cable.
Adhesive! on timber floors I always use BAL fastflex. It's a rubberiod adhesive which has more flexibilty than any other adhesive on the market. Then a flexible grout ie, Bal Superflex. If you lay a filler/skim coat over the underfloor heating cable first. you will make the laying so much easier and you will promote even warming of the floor. Do not turn the floor heating on untill 2 days after you've grouted, otherwise your grout could srink and crack. You can find me via the web if you need more imfo. Good luck.

Answered 9th Feb 2012

Serai Interiors

Member since 15 Feb 2011

Hi yes the ply does have to be wpb recomendation,s to screwing do differ but i always screw every 200mm then prime with SBR Bal bond not pva,yes you can tile over the underfloor heating using a flexable adhesive,i would recommend Bal,Mapie or Weber.

Answered 9th Feb 2012

A. G. Fright Tiling Specialist

Member since 28 Feb 2011

if you do not know the answer to these questions i would advise against you carrying out the works ,tile adhesive ,tiles grour flexi matting ect can all be expensive materials ,so why chance bodging it up

Answered 9th Feb 2012


Member since 7 Jun 2008

I have to agree with substructure,this is not a job for you to be doing yourself,Put your money to proper use & pay a pfofessional.

Answered 9th Feb 2012

m w building construction and property maintenance

Member since 28 Sep 2008

Agree with all points above but would consider putting insulating boards under the matting as May lose a good proportion of the heat through heat conduction from the matting to the substrate below the matting which isn’t what you want ideally.

Answered 22nd Jan 2018

Harts-End Bathroom Co.

Member since 12 Jan 2018

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