thermal boards or not

[cazzerroofer]

hi.
I am going to lay electric underfloor heating on 25mm wpb should i use thermal board or just the normal foam /polystyrene boards?

thanks in advance

 

[Richard C]

Thermal insulation boards will make the system much more efficient directing practically all of the heat into the room. They are also more beneficial in a suspended timber floor as they will help keep the ply relatively cool; constant temperature fluctuations in a ply (wood) tile base can cause problems with expansion/contraction which won’t help the tiles stay in place.

 

[cazzerroofer]

thanks for that richard c

so i will go with something like this

http://www.energysaving-shop.co.uk/...tm_source=GoogleBase&utm_medium=ProductSearch

and not this

http://www.screwfix.com/prods/75113...styrene-Insulation-Boards-Pack-of-8 ?ts=28184

or this

http://www.astra247.com/5364/Heatin...Insulation-Board/6mm-x-600mm-x-1250mm/froogle

also is this a good price on the thermal board i need about 8m2

cheers thanks in advance

 

[Richard C]

so i will go with something like this
http://www.energysaving-shop.co.uk/...e=GoogleBase&utm_medium=ProductSearch[/QUOTE]
Don’t know them from Adam; may be made by one of the major insulation board manufacturers but who knows.

and not this
http://www.screwfix.com/prods/75113...styrene-Insulation-Boards-Pack-of-8 ?ts=28184

or this
http://www.astra247.com/5364/Heatin...Insulation-Board/6mm-x-600mm-x-1250mm/froogle

Interesting why you dismiss it, is it cost? Its top quality stuff & I would have gone for that or Hardi; you tend to get what you pay for. Price will vary so much & it’s really down to search & perseverance on what you can negotiate.

 

[cazzerroofer]

Hi
I haven't dismissed them I just thought you said thermal boards were better than those blue boards.
Cheers

 

[tictic]

marmox ins. boards 9/10 for me...

Warm Up ufh, do their own insulation boards to,.. as do most mfr of ufh or they will recomend a board for their wiring or matting systems.

 

[Richard C]

Hi
I haven't dismissed them I just thought you said thermal boards were better than those blue boards.

Sorry I don’t understand, these are thermal boards; http://www.marmox4u.co.uk/marmox_insulation.php
As I & tictic said, some of the "own brand" boards are very good & probably made by reputable companies, you just have to discover who makes what to decide how good they are. It used to be very easy as it had to be printed on the label but not these days as some government Quango changed all that

 

[cazzerroofer]

Marmox it is then
Cheers fellas

 

[cazzerroofer]

hi.

MY plumber/tiler who will be laying the tiles and underfloor heating says.

thermal/blue boards are a waste of money.

It will be ok straight onto ply(wpb) he says the blue boards and such might make the tiling crack through expansion and stuff, and because i have some insulation under the ply (crown roll loft insulation) the heat wont be lost.
do you think that i should get marmox boards any way and put them down.

thanks in advance.

 

[Richard C]

MY plumber/tiler who will be laying the tiles and underfloor heating says.
thermal/blue boards are a waste of money.

That’s his opinion not based on technical fact; I’m sure you will find many who will agree but, on the other hand, many will also disagree. It really depends what standard you want & if you’re prepared to pay the additional cost for the benefit it gives.

It will be ok straight onto ply(wpb) he says the blue boards and such might make the tiling crack through expansion and stuff,

Well of course you can do without the insulation boards or a SLC over the heater mat but you will loose the benefit of rapid response warm as the heat won’t be reflected up into the room instead of into the floor & you’ll never be able to repair the heater mat if you need to; why not ask the heater mat manufacturer for their advice. No insulation board will also subject the ply base to wider temperature fluctuations & as wood expands & contracts to a greater extent than tiles, IMO, that’s more likely to lead to tile failure than less because there will be more “expansion & stuff”.

and because i have some insulation under the ply (crown roll loft insulation) the heat wont be lost.

That will make no difference to warm up response of the UFH & won’t isolate the ply from the heat source.

do you think that i should get marmox boards any way and put them down.

Your tiler sounds like a bit of a knob to me but the fact he’s a plumber might have something to do with it. From the advice he’s giving you, I’d be inclined to check out his previous work if you’ve not done so!

Tiling isn’t rocket science but you have to understand the materials your using & there is more skill involved; it’s not the same as fitting bogs, baths & plastic waste pipes, bending a few pipes & wetting in solder fittings (which I also do). I do bath/shower room renovations which includes fitting/plumbing the appliances (including power showers), structural work, plastering & tiling. You’ve been given similar advice from two of us, it’s your call really!

 

[cazzerroofer]

marmox it is then.

i knew deep down i wanted some sort of board under the underfloor heating it makes sense.

thanks