Underfloor heating mats

[Op1988]

Hi,

I'm going to be installing underfloor heating mats (150w) but I'm after some advise on the insulation boards to put down first. They seem expensive I was wondering is there a cheaper alternative? Or am I going to just have to buy the boards they recommend with the mats?

Iv never installed underfloor heating before they look pretty straight forward? Any advice would be welcome.

thanks

 

[trev]

Is it for a paying customer? If so give them a choice on the insulation. Google will be your friend on this

 

[Op1988]

It's for a family member. Iv done some research on this and it says to use insulation for best results. Just wondered if anyone has used a cheaper alternative?

 

[trev]

I'd ask them what they want mate. Explain the options then let them make an informed choice but I think I'd be steering them towards the best quality insulation they could afford.

 

[telectrix]

did our new shower room/bog with U/F supplied by ambient.they supplied all the gear, heating cable, stat, and insulation. was not too expensive. ( was not a mat as such, but a measured length of cable calculated by them from the sq.m. floor area.). they supply 2 U/F sensors, so that if 1 should fail, there's a back-up saves hassle of trying to replace.

 

[Op1988]

Yeah I know what your saying. I have explained and they want insulation I was just seeing if anyone uses an alternative insulation board before I order the recommended ones from the underfloor heating company?

Thanks for your help

 

[meridian911]

Usually we use the one from the underfloorheating store, I think it's premium xs or something but once or twice have used tile backer board that the builder supplied

 

[Op1988]

Thanks guys, iv just done A little more research and found that celotex or kingspan boards can be used. They come in much bigger boards, 1 board covers 2.88sqm where as the xps boards only cover .72sqm. Has anyone used the kingspan or celotex boards?

 

[trev]

Not for UFH but I've used them for other stuff. Insulating rafters rather than putting tickly wool in

 

[telectrix]

It's for a family member. Iv done some research on this and it says to use insulation for best results. Just wondered if anyone has used a cheaper alternative?

here's a much cheaper alternative.

 

[Op1988]

Celotex do a 12mm board and kingspan do a 10mm board both 2400mm x 1200mm. So basically 1 kingspan/celotex board is 4x bigger. I also phoned warm up (the underfloor heating mat I'm going to use) and they said it would be fine to use. So iv answered my own question ha. Yeah thick socks is a good shout I'll tell them ha.

thanks again lads

 

[dansk]

STOP! kingspan and celotex or any foil faced PIR insulation for that matter cannot be tiled directly on to, the adhesive will not key to the foil, secondly they don't have the point load strength of TTB. PIR insulation is fine for wet UFH under a screed, not for your intended use.

 

[telectrix]

as above. always use whatever the ufh supplier/manufacturer recommends. then, if it's wrong, it's their fault.

 

[Op1988]

I'm not going to tile directly onto the insulation, I'm going to lay the mat on the insulation then self level over it. The guy I spoke to at warm up said that would be fine?

 

[telectrix]

this thread is making the socks look more attractive post by post.

 

[dansk]

A little background ive been installing electric UFH for over 10 years now - warmfloorsonline.com and underfloorheatingservice.co.uk

Warm-up are talking "rubbish" - you need an XPS insulation not PIR for under-tile application.

Firstly - you need to bond the insulation to the sub-floor with flexi tile adhesive or screws and washers onto timber - tile adhesive wont key to the foil face type - secondly you are going to SLC over the cable, again which wont bond/key to the foil, thirdly the celotex/kingspan will depress and cause the tiles to come loose - that's if the SLC hasn't already broken up in pieces.

Dont buy from the big PLC who wont really look after you - i don't really care who you buy from but you are lining yourself up for a massive fail here.

TBB are expensive for a reason, that's because a lot of R&D has been carried out, these boards can take 10 tonnes/m² vertical load, proper TBB have a cement fascia for the adhesives and SLC to key to.

But after all this are they really expensive once the job has failed? nope - bite the bullet and buy the proper insulation boards for the job.

Further reading: What Tile Backer Boards Do You Use? Green Building Forum - Can you put floor tiles directly on top of high density EPS

 

[Delboybully]

It sounds to me like Dansk knows what he is talking about and if I were OP1988 I would follow his advice

 

[Op1988]

Thanks for the info dansk, what your saying does make sense. This is the reason I came on here and asked the question!