To turn on or not to turn on???

[slikt]

I have just done my flooring and I have installed UFH, i've had loads of conflicting advice even from Mapei. . So. . . should I switch it on yet or wait another week?

Flooring is as follows. . .Primed floor with 2 coats SBR, Laid insulation boards on Mapei proflex (Grey), then UFH mat, used Mapei Renovation screed over the top, left a day and then used Mapei Proflex (white), used a 20mm round notched trowel, left a day and grouted. That was 17-18 days ago, can I fire it up, or wait at least 3 weeks, I only ask as I have had people tell me wait from 3 days to 28 days and everything inbetween. . so i'm slightly confused and have bloody cold feet

 

[nybor62]

turn it up gradually say about 15c increase it every other day should be fine imo

 

[Gazzer]

I wait 14 days at least and then say it can be turned on slowly as above.

 

[Stewart]

Couple of weeks for me then turn it on. Then turn it up a couple of degrees a day from the ambient temperature of the floor.....


Created on iPhone.....

 

[slikt]

ok. . just turned it on @ 23 degrees as the room temp was 21.5 and had those first few mins of thinking 'is it working' and its started getting warm, so i've set the 'hold' at 24 hours at this temp, so am i to assume that after the 24 hours I raise it by about 1-2 degrees a day till what max temp and then come down 1-2 degrees a day till back at ambient temp?

 

[Time's Ran Out]

When you turned it on what was the FLOOR temperature?
21.5 degrees is warm for a screed floor start up temperature.
Just turned on a UFH to a wet room and it was 16 degrees on wood.
Always increase by 1 degree per day, but IMO no need to go above 28 degrees.
Thermostats have a limit of approx 40 degrees but it would mean it would never switch itself off and even at 28 degrees the heat loss into the room usually maintains a continuous temperature.

 

[slikt]

Sorry, the thermostat said the floor temp was 21.5, our house is very warm and the floor wasnt really cold before it was switched on. Plus it wouldnt switch on unless the temp was below what I wanted

 

[Stewart]

My last two floors had an ambiant temp of 21, so sounds fine to me. Just take the floor up to the max temp that your gonna run the floor at.


Created on iPhone.....

 

[slikt]

My last two floors had an ambiant temp of 21, so sounds fine to me. Just take the floor up to the max temp that your gonna run the floor at.


Created on iPhone.....

Cheers Stew, i probably wont need it any higher than 24, so its certainly not gonna run at an extreme as some people I know have it at.

 

[slikt]

Ok. . not a happy chappie as i've noticed hairline cracks in some of the grout lines !! I've done everything and more to stop this happening, even waited over 3 weeks till I switched the floor on and then had it running constant for two weeks turning it up 1 degree every 24 hours. . and yes I followed the mixing instructions of the Mapei grout to the letter. I know I can rake out the grout and re do but that in itself is gonna be hard. Not happy dot com! Why would this of happened?

 

[nybor62]

is there any bounce in the floor at all , what is the total floor area

 

[slikt]

No bounce and floor prep was done to the letter, just tapped all the tiles and no sound difference either, its soild, total area is about 13sqm. I asked loads of questions on here to make sure it was done exactly as it should be done. Wondering if its down to the grout itself as heard stories of some Mapei grout failing?

 

[Mike]

Did you overwet the grout when washing off? I haven't heard of mapei brought failing, just discolouration mainly due to inconsistency in the mixing. Have you left the heating on? Is the cracking getting worse?

tapatalk on my HTC

 

[slikt]

Did you overwet the grout when washing off? I haven't heard of mapei brought failing, just discolouration mainly due to inconsistency in the mixing. Have you left the heating on? Is the cracking getting worse?

tapatalk on my HTC

Nope, it was a damp sponge as I had to buff them up after with dry rags, its not all over probably only half a meter in total. I'm just wondering if any of the prep work has failed as thats gonna be a major issue and as said, I did everything to the letter, OCD in fact. The heating was on for over 2 weeks whilst 'running in' and after that it was put on a timer to come on in the morning and then again in the evening. Very confused and really dont want to have to rake out all the grout due to having a brand new kitchen, but if it has to be done then it has to be done?

 

[Mike]

Hopefully it is just the grout for some reason. How wet did you mix it? It should be stiff enough to stand in the bucket and not slump and level out

tapatalk on my HTC

 

[slikt]

Hopefully it is just the grout for some reason. How wet did you mix it? It should be stiff enough to stand in the bucket and not slump and level out

tapatalk on my HTC

Yeah it was stiff enough, as said I read a few posts about some people having issues with that grout so I made sure I used the whole bag to the recommended amount of water, didnt want to do guess work by splitting the bag. Oh well, recommend the best and cleanest way to remove that type of grout. .lol

 

[Gazzer]

You say some people are having issues with Mapei grout ? Do you mean cracking or colour ? As I havent heard of any cracking issues if done right !

 

[Ian]

I've had a brief read through this thread and can't find anything that says what substrate you have laid on. Apologies if I've missed said info!


Sent via Tapatalk for iPhone

 

[slikt]

I've had a brief read through this thread and can't find anything that says what substrate you have laid on. Apologies if I've missed said info!


Sent via Tapatalk for iPhone

The substrate was concrete that was primed with 2 coats of SBR

 

[Gazzer]

Neat SBR or mixed with water ?

 

[ian158]

well i done my first ever UFH last month, was for my cousin, i used 6mm hardi backer, nicobond flexi hardset and nicobond grout, and am glad say all fine, phew, but sorry to hear of your problem.

 

[Billy Hunt]

On the cracking grout,What size spacers did you use?did you leave expansion gaps around the perimeter? Did the floor area used to be two floors?

 

[DHTiling]

Pics would be good.

 

[slikt]

It was diluted as per BAL's recommendations I called them to make sure, I cant remember what the ratio was, 1:4 maybe

 

[slikt]

On the cracking grout,What size spacers did you use?did you leave expansion gaps around the perimeter? Did the floor area used to be two floors?

4mm spacers and it has min 10 mm expansion gap. Floor is one level and all concrete.