Under floor heating advice please.

[rj1884]

Good morning. I'm after a little advice if possible please. I've read some other threads regarding the commissioning of under floor heating. I'm trying to get my head around it so I apologies at the start. I'm due to tile a large area which has under floor heating encased in 65mm sand and cement screed. The pictures below are of the end of the pipes which run through the screed. Can someone explain the commissioning process when using a piping system like this please. Does this system have to be commissioned prior to tiling. (Probably a silly question)
Again I apologise if this has already been explained.
Thanks in advance.

 

[Chalker]

Have you fitted this yourself?
Those pipes going to other rooms will need sleeving to keep the heat in the room it is designed for.
It will need commissioning before any tiling is done. Will post how to this evening.

 

[rj1884]

Thanks for the reply. They've been installed by someone else. If you could that would be great thank you.

 

[rj1884]

Good evening all. Quick update. Spoke with the builder regarding the commissioning of the UFH which he initially said had been done then didn't know what it meant.
His answer was I've never done that I've nevertheless done that before before laying tiles.

 

[Chalker]

If this was a screeded floor with no heating, you would wait the correct time for drying, then test for moisture. If this was ok you could then tile with a suitable primer and adhesive ( maybe a decoupling mat).
But with underfloor heating, you need to have a dry floor and to have brought the floor to a working temperature. After a week or so you can put heat through the underfloor at a low temperature, making sure you ventilate the room ( open windows) or use dehumidifiers. Over the next week you can slowly, day by day turn the temperature of the pipework up to working temperature. Once the floor has been tested for correct moisture level, you turn the heating off for a day. Then you can tile. Depending on adhesive type, leave between 5 -7 days to cure before turning heating back on.

if you tile before doing any of this you will trap all he moisture in the screed. This can un-bond the primer/sealer, then tiles will come loose or crack.

 

[rj1884]

Hi Chalker. Thanks very much for posting that. Can I just confirm a few things please. So once the floor is dry you turn the heating onto low temperature. Does it have to have Ben left at low temperature for a week or once it's reached the low temperature you can then the temperature up day by day over a period of a week.
once the moisture is correct level do you just turn it off or run it back down in stages.
Can you recommend a decent hygrometer. Also what temperature would you set the temperature as low and what would you take it up to.


Sorry for the questions mate.