Comissioning of wet UFH - TilersForums.com

[kaharrison9]

Good Evening.

I'm sure it will have been covered but have spent 1 hour looking.

Soon have a wet UFH system on an anhydrite screed coming up and would like to know the plan for the comissioning of the heating system.

At what temperature i start at,over how many days,what the maximum temp i go to.how long it's then turned off.etc.

Many Thanks

Kev

 

[bugs183]

This will be a post worth watching as its very relevant at the moment.

 

[Ajax123]

Start at approx 20 to 25 degrees for three days. Then increase by max 5 degrees per day up to maximum of 55 degrees. Leave at this for minimum three days (no maximum) and then reduce by maximum five grees per day down to 20 to 25 degrees (some systemss dont allow below 25) then switch off for three days and then moisture test. If dry, prime and tile assuming prep done to remove construction detritis from screed.

 

[bugs183]

Hi Ajax.
Good to have someone here that knows about poured screeds, and is help in high regarg by all the members/
When you say start at 20-25 degrees, how long after the screed has been poured can you start this?
And in your opinion what is the best methods/methods to moisture test?
Cheers.

 

[Ajax123]

You can comission after 7 days. If you are using the heating to force dry the screed as well you should leave it up at its highest temperature for a week to ten days and make certain it is well ventilated to remove the moisture from the air above it.

Moisture testing is best done with a flooring hygrometer. Cost approx £80 but well worth the cash. This test takes about 48 to 72 hours to do properly.

What coverings are you putting down?

 

[kaharrison9]

That's great Ajax.

So valuable this sort of advice.

When we say degrees i take it that it's the atmosphere temperature not the screed?

I am looking at a digital floor hygrometer at £97 at www.yorksurvey.co.uk which is local.

Would this be fine?

The screed was poured in December,sanding tomorrow,5-1 lightly primed with N+C primer,ditra down with N+C gypfix,then an S1 cement adhesive between the Ditra and tile.

Can you see any flaws?

Many Thanks

Kevin

 

[Ajax123]

Flow temperature of heatin system. This is usuall set either at the boiler or he manifold and the room stats will nedd to be over ridden or tuned up full.

 

[Ajax123]

And the loor hygrometer is perfect.

 

[kaharrison9]

Much appreciated.

Kevin

 

[bugs183]

Cheers.Really helpful advise that.
I'll be getting an hydrometer asap, as poured screeds are taking off around here.
Any tips on using one of those whilst we're picking your brain????