DIY Related: concrete / wood floor

[Rob#1]

Hi, any help greatly appreciated; basically I plan to tile my open plan kitchen (concrete floor) & dining room (conventional floor boards) approx 35 sq mt. I plan to install under floor heating to take the chill off the tiles only. Raising the height of the floor level too much is a concern.

Q1 - 100watt or 160watt matt’s
Q2 - plywood or backer boards or both?
Q3 - what if anything do I need to do for flex where the two different floor materials meet?
Q4 - can anyone recommend a cheap supplier for the backer boards if they are required.
Q5 - I live near Manchester and have seen the tiles I want in Tile Mark - does anyone have experience of this company / quality - does anyone have alternative quality suppliers who are reasonably priced

Thanks in advance for any help / guidance

[whitebeam]

What tiles are they, Porcelain, ceramic etc

[Barry bp]

10mm insulationboard decoupling mat 100 watt

[andy8758]

Hi Rob and welcome.

Before you start - under tile heating works best laid onto some form of insulation board, the thick the board the more efficient the heating. Usually the under floor heating manufacturers recommend a 10mm thick board, although a lot of us installers use 6mm boards if the customer is trying to keep floor height down. I do not recommend laying under floor heating unless you lay down insulation boards first.

It is not just about how hot the tiles get, but how efficient the system is. Remember that you are paying electricity in kilowatt hours - and 100watts over 35 square meters is 3.5 kilowatts. The matting comes in different power ratings dependant upon the type of floor it is laid on - it is recommended that 100 watt (per square meter) is used over floor boards, and 150 watts (psm) over concrete. I would therefore advise you to zone the heating - a 150 watt system in the kitchen and a seperate 100 watt system in the other room over the floorboards.

Before you start I recommend you watch this video from warmup (one of the under floor heating suppliers)
Warmup | Underfloor Heating Videos | Warmup® Underfloor Heating Videos

[terry the tiler]

160/200w matts , 6mm insulation boards, uncoupler and hardy. flexi spf. what tiles ru laying ?

[Barry bp]

100w for warming tile 150/160w parcialy heats room aswell depending on genral insulation of room 200w not suitable over wood even with insulation board
fast heat up can be prob i would stick to 100w unless you really need the heat and latex mat before tiling much better

[Rob#1]

Hi, Thanks everyone for the advice, we (wife) are still undecided on the tile type - it will be either slate or porcelain depending upon cost.

the backer boards that i have seen state that they have the same "U" value as the insulation boards so these should be ok?

i was going to use 10mm as i thought it may add additional strength to the floor where the two floor types join (concrete & wood) - do you agree? 6mm would be preferable as the floor height is a real issue

as i only want the chill taking off the tile 100w should be ok then?

Thnaks for all the advice

Rob

[Brinkley]

if using slate (natural stone) please consider using a decoupling membrane ditra or dural ci

[Barry bp]

6mm board ok then decoupling mat then ufh then latex and haray! ready to tile thats the way i would go time and expence, but a job done properly, it will look good for a long time and be cheaper in the long run best of luck what ever you decide i would'nt want to do it unless i was a tiler o i am