Hello everyone just a quick question. I have the opportunity of laying ply down on straight onto joists in an upstairs bedroom in preperation for tiling . Now I know that probably 25 mm ply would be the best option to gor (or at least this is what I have been led to believe), however are her any problems with laying 18 mm ply. I'm just thinking about floor heights in the door way as well as tile heights etc. Also if laying UFH does insultion board need to be used, (on ply) if so any particular brands you recomend.

THanks - Ernie

Ernie,

Seems a shame to pull up all the current boards and opt for 18mm over 22/25 to avoide trimming a door a few mm. Is that the only reason you're opting for thinner ply? How many doors are there involved?

And as for the insulation, you should be fine without to be honest. If you have the chance to, put some fluffy floor insulation (like a loft insualtion type stuff) under the ply as you fit it and that'll keep it snug and warm when the heating is on and it'll help with heat-up and cool-down times meaning the underfloor heating wont be on as much as without insulation.

hi Dan thanks for you answer. At the moment there is chip board down so dont want to tile over that. There are two doors, one going into the bedroom from the landing and one into the ensuite from the bedroom. There is a step into the ensuite hence my thinking of using 25 mm ply to take some of this up but at the moment no step into the bedroom from the landing.

Im just trying to get the best of both worlds, thinking 18 mm will be the best compromise as long as it is strong enough. I think this meets / exceeds BS. Not bothered about the door because there will be a new one anyway.

Ta Ernie.

SOrry, one more thing,as far as the UFH goes. Im looking at Uheat, Thermonet and warm up as potential products to use, does anyone have any ideas which would be the best/most reliable to use.

I spoke to U heat who were extremely helpful and seem to be the cheapest but dont want to have to do this again 6 months down the road if you know what I mean !

Any comments would be appreciated.

Ernie.

You will have no problem with U Heat i used to use Warm Up but had a problem with the Programable thermostat...it was mended eventually but it was a lot of hassle with Warm Up.