kitchen, ufh, substrate

[squarecut]

I'm a decorator by trade and training as a joiner with a little tiling experience. I'm doing my own place in readiness for a sprog and figure I can do it with a sparks I know as long as I follw the right advice, so I would appreciate any help you can give on the following:

Planning to tear up floorboards, lay down 22mm wbp ply, followed by insulation board, ufh, slc and simple quarry tiles on top.

1. Is 22mm enough? some here seem to favour 25mm
2. Does any one use wbp T&G boards? if so does this do away with need for noggins?
3. Whats the best brand of insulation board and what fixings do you use to stick it down? (as well as adhesive?)
4. Can you recommend a brand of electric ufh?
5. Ive got a few bags of ardex x77 I'm planning on using, I've had it for a while as project has been delayed by quite a while (kept indoors and dry), has anyone used it?
6. Finally I'm planning on using 150mm quarry tiles<, the tough uniform oxblood ones you see everywhere.

I'd appreciate any help you can give on this and any tips on where best to source what I need (I'm in Hackney, London)

Thanks all!

[whitebeam]

Would'nt worry about the insulation board, lay ufh then slc, then tile but make sure it's flexible adhesive and grout on the ply.

Just make sure there's no bounce in the floor

[Daz]

In contrast to Whitebeam, I would use insulation boards as I don't like installing electric UFH direct onto ply, just my personal preference.

I use Ardex X77 on walls as it is very good for large formats, but never used it on a floor as I prefer rapid set for floors.

25mm ply will obviously be better than 22mm but as long as you have sufficient noggins and ensure that there is no deflection in the floor, you will be fine.

Check out one of our sponsors, uHeat Underfloor Heating | Electric | Floor Insulation | Uheat, for UFH and insulation boards.

Don't forget to use a flexible slc, such as Arditex NA or Mapei Fibreplan, and a flexible floor grout too.

Good luck.

Daz

[squarecut]

Thank you both. I suppose 22mm should be sufficient esp if I choose to put insulation on top. Whitebeam, are you saying that insulation doesnt do a lot on ply?

Could you clarify whether I lay insulation over whole floor? (not just where matting goes down) It wouldnt do a lot under units etc. I know level needs to be same throughout but might be cheaper to use equivalent thickness of ply?

Should I screw down insulation as well as stick it down? If so what with?

cheers

[mikethetile]

22mm wbp will be fine, I would insulate under the ufh

[david campbell]

ditto the above,i would use insulation boards only if it is a large room!

[Dave]

Ply is a sort of insulator but adding the cement faced/ poly core backer boards will give a better substrate to tile too and increase warm up times, would substrates do not lose heat like concrete ones do..

[squarecut]

Its quite a big room (kitchen diner) the kitchen part being 5.4m x 3.5m, the adjoining diner, which wont be tiled (retaining its old boards) is 5m x 4.2m, and its freezing! The ufh wont be primary heat source but could probably do with all the help it can get.

A quick search has shown popularity of marmox. Seems to be decent gear but have never seen it, having only used wedi a couple of times on walls. Are they similar? and still not sure whether special fixings used to fix as well as addy.

Incidentally its quite common for chippies to fix t&g at right angles to joists and square edge boards along joists. Thats for normal flooring. Is it the same for tiling?

[Dave]

You will get a good deal on insulation boards here. http://www.uheat.co.uk/backerboard.htm