Jump to content


Advice please on underfloor heating on floor boards


  • Please log in to reply
13 replies to this topic

#1 jacci

jacci

    New Member

  • Members
  • Pip
  • 5 posts

Posted 20 September 2006 - 09:46 PM

I really need help. I have paid someone to install underfloor heating in my kitchen and hall and then tile the area. I was under the impression that the floor boards had to be borded over first. This has not happened. The underfloor heating matting has been placed directly over the floor boards. In the kitchen area the matting was then covered by a thick layer of grey adhesive and grout for wooden floors, then the tiles on top. In the hall there is only a thin layer of the adhesive and grout mixture with the tiles on top. Under the floor boards there is a space of approx 4 ft. Can any one tell me if it should have been laid differently, if so likely problems, and how best to proceed? Your help will be greatly appriciated.

#2 Guest_cwatters_*

Guest_cwatters_*
  • Guests

Posted 21 September 2006 - 12:04 AM

It depends how rigid the original floor was? If it moved a lot then a flexible adhesive on it's own might not be enough to prevent the tiles cracking.

Somestimes the UFH makers will provide guidance.. See "specification 2 - Existing Timber Floors with Undertile Heating".

http://www.floorheating.ltd.uk/tiling-specification.php

#3 caliwag

caliwag

    Advanced Member

  • Moderators
  • 1,819 posts
  • LocationYork

Posted 21 September 2006 - 08:25 AM

I assume there is no insulation below the timber. If so a lot of the heat will be heating the space beneath.

#4 steveo

steveo

    Member

  • Members
  • PipPip
  • 96 posts

Posted 21 September 2006 - 08:46 AM

Just to follow tiling regulations you would need to overlay the floor with marine ply or similar.

There are products like BAL Fastflex which you can use to tile directly to the floor boards providing they are screwed down and not just nailed and they are in good condition, but I don't think you are meant to lay heating cables directly on them due to the expansion of the timber etc.

#5 jacci

jacci

    New Member

  • Members
  • Pip
  • 5 posts

Posted 21 September 2006 - 09:12 AM

First thanks for all of you that posted replies. The original floor is over a hundred years old, in places it seemed to be quite rigid in others the boards moved. Under the floor there is no insulation. The tiles are really thick, but the grouting has statred to crack and the person who layed them said it was the mixture was to thin. Can anyone please tell me what they think is my best options from here? Thanks

#6 Guest_buildersmate_*

Guest_buildersmate_*
  • Guests

Posted 21 September 2006 - 10:38 AM

There are several things wrong with the job, as others have identified. 1) UFH depends on having good insulation underneath so one doesn't lose a high proportion of the heat downwards. 2) Wooden floorboards should be covered in quality ply before such a matting is put down or SteveO's idea implemented. 3) Very flexible tile adhesive and grout with flexible polymer included has to be used to allow the tiles to flex on the wood underneath as it moves.
Not only does the installer appear to have done any of these things, he also admits to you that his mix was too thin. Have you paid him / got any other leverage you can try and apply?

#7 jacci

jacci

    New Member

  • Members
  • Pip
  • 5 posts

Posted 21 September 2006 - 01:41 PM

He done two previous jobs, both good standard. I have paid him for materials for a job he is yet to do, so that really means I have paid him for the work if I stop him doing the other job.

Are my options to rip it all up and start again (unsure if it will damage UFH), can not do myself so costly, put insulation under floor boards, cut my losses and play the waiting game and see what happens in the long run or anything anyone can think of. If it was you, what would you do? Thanks for your time.

#8 steveo

steveo

    Member

  • Members
  • PipPip
  • 96 posts

Posted 21 September 2006 - 02:22 PM

The heating will always work, so the actual problem is only visual at the moment (cracking grout) but could eventually cause tiles to lift.

A cheap easy solution..... Just regrout the odd cracked grout joint using an Epoxy grout, very flexible and can't crack, this will bond the tile edge to the tile edge... for life!

Then... should in the future (god forbid) the odd tile comes loose, lift it, clean it off and then restick it using BAL Fastflex, again, this stuff you could tile your curtains with if you wanted, very very flexible and sticks to anything. This is also suitable for use with UFH.

It isn't really a long-long-term plan but will certainly do the job for a while. Eventually you'll end up with lots of the floor flexing more than other areas due to the fastflex moving as much as the substrate wants to, and the less flexible adhesive trying to hold things still which will end up cracking more grout but that's after you've done big patches of fastlfex-ing.

Both epoxy grout (BAL Easypoxy) and rubber based flexible adhesive (BAL Fastflex) are available from www.toppstiles.co.uk

Hope this helps :-)

#9 steveo

steveo

    Member

  • Members
  • PipPip
  • 96 posts

Posted 21 September 2006 - 02:33 PM

By the way... for future reference, I messaged a tiler on a tile forum for this info' for you which is at http://www.tilersforums.co.uk just in case you want to ask there too. I messaged one of the guys I know would have an answer so the message isn't actually visible to guests or whatever, I should have thought to ask in the public area thinking about it now, then I could have linked to the specific post - tut haha.

#10 jacci

jacci

    New Member

  • Members
  • Pip
  • 5 posts

Posted 21 September 2006 - 08:15 PM

I would like to thank everyone for there time and patience. If anyone has any final tips, they would be most welcome.

I still feel gutted that that this problem has occurred but reassured that there is still honest and helpful people in this world.

One final thing. I have a partition wall to be built, walls + floor to tile, bathroom suite to install, where can I find a good craftsman who charges reasonable prices? I live in the North East of England, Near Newcastle.

Thanks again for all your help, greatly appreciated. Jacci

#11 steveo

steveo

    Member

  • Members
  • PipPip
  • 96 posts

Posted 22 September 2006 - 09:05 AM

http://www.uktilersin.co.uk/northeast/co.durham/vps/ is in Co. Durham. Also, not too sure how ready this site is i've not clicked through the areas http://www.tilersinyourarea.com/ - These a wall and floor tilers though not full bathroom fitters.

#12 woodyoulike

woodyoulike

    Regular Member

  • Moderators
  • 600 posts
  • LocationAshford, Kent

Posted 22 September 2006 - 10:07 AM

Steveo, can't help noticing your signature is ever increasing ;-)
Guardians of Quality
Wood You Like, Natural Wooden Flooring, based in Ashford Kent: www.woodyoulike.co.uk
Supply (& install/restore - Kent area) of high quality wooden floors - including design parquet. Authors of "Wooden Floor Installation Manual"

#13 steveo

steveo

    Member

  • Members
  • PipPip
  • 96 posts

Posted 25 September 2006 - 10:04 AM

Yes... I think I'm mixing up 'using' with 'abusing' in this case. :-)

#14 tiling_contractor

tiling_contractor

    New Member

  • Members
  • Pip
  • 1 posts

Posted 19 March 2010 - 08:03 PM

Ditra matting is what i normally use


check my photos to see what it looks like http://www.nottinghamtiling.co.uk/gallery.html
its the orange matting made by schluter