Warm Up UFH Problem

[scotty74]

Hi,
I've recently installed a Warm Up underfloor heating system in my down stairs bathroom. It's no exaggeration to say that it takes all day to get up to a decent temperature (ie 30 degrees or so) and also really struggles to achieve much above this. I was expecting a good level of heat in 20 - 30 minutes.
The sub-floor is concrete, onto which I fitted 6mm insulation backer boards, a product by the name of "No More Ply", before laying the heating mat and tiles.
I have spoken to Warm Up technical support and they said it sounded like the heat was escaping downwards and I should have used Warm Up's own insulating boards. Thanks for that!! Maybe they're right, but my tile supplier said the "No More Ply" boards would achieve the same results. Have any of you had a similar experience?
Any thoughts would be appreciated,
Cheers, Scotty

 

[DHTiling]

I didn't know NMP was an insulating board..?.. plus i would say 10mm minimum.

 

[Gazzer]

I have had this argument with the NMP rep and its a load of tosh. My tile supplier said it was fine but during my discussion with the rep , it was obvious that by asking the right questions he was backing down.
You should have used the correct boards, what you have is no different to laying direct to the concrete floor.

 

[Ajax123]

I agree with Dave. I did not know no more ply was sold as an insulating board - might be wrong though. Even 6mm of PU rigid board insulation will not do very much. I suspect that warm up are right about the heat escaping downwards. Effectively using the concrete underneath as a heat sink. It may warm up eventually but I suspect your ideas of a 30minute response time are a little optimistic to say the least.

As for using Warm Ups own boards that is just sales pitch. Any insulating boards of equivalent or better R value would have done the job.

 

[scotty74]

I have had this argument with the NMP rep and its a load of tosh. My tile supplier said it was fine but during my discussion with the rep , it was obvious that by asking the right questions he was backing down.
You should have used the correct boards, what you have is no different to laying direct to the concrete floor.

I suspect you're all correct. Maybe a few more pertinent questions at the time of purchase wouldn't have gone amiss. As it goes Sir Ramic, it was a tile supplier in Wordsley that gave me the advice on the NMP boards. Also it does state in their literature that it is suitable as an insulator for electric UFH, whatever that's worth. Thanks anyway.

 

[Gazzer]

I suspect you're all correct. Maybe a few more pertinent questions at the time of purchase wouldn't have gone amiss. As it goes Sir Ramic, it was a tile supplier in Wordsley that gave me the advice on the NMP boards. Also it does state in their literature that it is suitable as an insulator for electric UFH, whatever that's worth. Thanks anyway.

Yep same shop as i use. I have had this out with them but its what the sell and if NMP leaflets say its got insulation properties then they go by that.
I quoted a job last year and told the client about thermal insulation boards, it was agreed we would use Warmup boards which is also sold by the same shop. When they delivered to site it was NMP. Lots of phonne calls followed to which i ended up talking to the rep, he backed down when i asked if it had the same insulation properties as the warmup boards. IMO it has no more insulation properties than the adhesive used to lay the tiles....Its only a cement board.
As for the shop in question, mostly good but you need educating in some areas....YES I KNOW YOU ARE READING THIS !

 

[scotty74]

Oh well, they say you learn by your mistakes. I reckon the ultimate solution is to start again. Not cheap and not good for my marriage!

 

[Scott]

Who advised you that they were the right thing to use? If the tile sipplier said they would acheive the same results then surely they are at fault?

Id be speaking to them, havent they sold you something thats not fit for purpose?

 

[Ajax123]

Who advised you that they were the right thing to use? If the tile sipplier said they would acheive the same results then surely they are at fault?

Id be speaking to them, havent they sold you something thats not fit for purpose?

I sort of agree with this but essentially it depends on what they have said and how they have sold it. Everything has some sort of insulation value and if this has been explained in terms of a R value or Lambda value then there is probably little to be done. However if it has simply been stated that the boards are suitable for underfloor heating as an insulation layer then I think there would be a very good case. Whatever happens the propensity of the court would be to come down ont he side of the domestic customer if faced by a large company. It is usually incumbent on the large company to prove their sde of things rather than the othe way around. To be honest I think I would push this one a bit harder than simply saying - chalk it up to experience.....