Help!! Has the underfloor heating been installed wrong!!!

[jay]

If you have anymore questions ask away there is normaly someone on line and let us know how you get on ,good luck

 

[Gazzer]

Best talk to the guy 1st, he may have the answers to what we can not see. Saying that, tiling direct to Chipboard is a no no for me.

 

[ben2579]

what time do you guys get up? Will call him ASAP - but just to be clear

Underfloor heating should never be laid to chipboard

And tiles should never be laid to chipboard although some have got away with it in the past?

 

[Tregah]

Agree with the comments above. Once (when) fitted, its critical to keep the distances and never cross over the heating elements. the chasing should allow the element to be embedded deep enough to be (as near to as possible) flat without interfering with the tiling. Page five of the PDF below will show the fitting to a timber floor.

Below is a good PDF of how to lay Devimat

http://www.heatandplumb.com/brochure_downloads/devimat/devimat_instructions.pdf

Good Luck

Graham

 

[Uheat - Keith]

Just a quick one, the Devi 550 always comes with a floor sensor in the bottom of the box, so tilers must have seen it there when removing Controller from said box.

 

[ben2579]

Yeah everything seems wrong about the installation - time for a new tiler I think

 

[jay]

As Siramic said have a talk to him first

 

[Andy Allen]

it dosn't sound good, but talk to the guy first before you hang him out to dry..

 

[Andy Allen]

snap lol...

 

[B16JOG]

Hiya,

Jay's feedback above is spot-on in my view (and I'm just a keen DIYer!)......I'd also suggest you screw the chipboard down every 6 inches before the cement board goes down. Good luck with it

 

[ben2579]

it dosn't sound good, but talk to the guy first before you hang him out to dry..

just spoke to him - he said that the backer board was not necessary as it was such a small area ( 900mm by 1500mm) and the chipboard had been so well secured. He thought the matt installation was still ok? NOw time to switch? He said on bigger jobs he would use ply but this was so small and solid it was not necessary.

now your thoughts please

 

[jay]

if it was my job i would 6mm cement sheet it glue and screw .lot better substrate to tile on and will help contain the heat

 

[ben2579]

are there any votes for sticking with him?

 

[B16JOG]

When looking at the job, think of the whole floor, not just the bit that is being tiled. I don't know your bathroom, but let us assume there is a bath, shower, basin and toilet. Now, think of the different strains that are being put on that floor: a full bath + an adult is quite a bit of weight which then looks to spread that load. This is why securing the floor before tiling is so important as, with a wooden floor, there is quite a bit of "flexing" happening. We may not notice it, but your tiles and grout certainly will.

 

[Dan]

Chipboard is just bad in bathrooms full stop. It swells waaaaay too much when it gets even the slightest bit of damp on it.

18mm marine ply minimum. But as it's a bathroom I'd go with the cement boards as suggested.

It wouldn't have been too much of a maul if it's such a small area to simply cut out the chipboard and replace with ply, then overboard.

The heating mat is fine to be used in bathrooms though providing the thermostat is the right one for bathrooms, or is placed outside the bathroom.