Remedial Works - Damage to UFH Pipes (Aluminium Visible)

[Gaf]

New build with a contractor. A WC outlet pipe was put in the wrong position and had to be moved. UFH was already down when it was spotted. Got the nod the pipe had been moved and took a spin around for a butchers.

 

Noticed the UFH pipe was fairly scraped. It's not obvious on the pictures but I can see the inner metal beneath the outer white plastic coating in two spots.

 

From reading posts here, if no metal is visible then the advice is just make sure it's pressure tested, but if the metal is visible it has to be replaced. Assume there's not a donkey's chance in hell of the whole floor coming up and the job being redone... Not sure how it was all laid but the whole floor is 130m2 and it's all UFH.

 

How strong and long lasting are 'connectors' that are used when a piece of UFH pipe is replaced? Anything I should be making sure is done to limit the chances of a leak in 10 years time when I'll have no recourse?

 

The A2W unit isn't even close to being installed so no idea if it can be pressure tested?

[JohnMo]

I would want that bit replaced. Pressure test would be done without the heat source. You can test with air or water. I would want the whole UFH system testing while they are at it.

[Dave Jones]

hard to tell but looks like your screed is thermally bridged to the blockwork  turning your walls into giant heat loss emitters?

 

whats the other un-insulated pipework at the back ? Hot and cold feed ? Not good.

[dpmiller]

I dunno Dave, looks like white edge insulation and white pipe insulation are both in place...

[Gaf]

49 minutes ago, Dave Jones said:

hard to tell but looks like your screed is thermally bridged to the blockwork  turning your walls into giant heat loss emitters?

 

whats the other un-insulated pipework at the back ? Hot and cold feed ? Not good.

I think the insulation between screed and blockwork was damaged when they were pulling up the screed - there is a barrier running all around between the screed and block work.

 

Those pipes in the background have the white soft insulation surrounding them.

Edited August 27 by Gaf

[Gaf]

What I'm most concerned about is how strong and long lasting are the 'connectors' that are used when a piece of UFH pipe is replaced?

 

Anything I should be making sure is done to limit the chances of a leak in 10 years time when I'll have no recourse?

[JohnMo]

Joints should be fine, you need a 24 hrs leak test at 6 bar done prior to accepting.

 

Read here fir direct reference to leak test pressure 

https://www.johnguest.com/gb/en/resources/blog/common-underfloor-heating-mistakes-during-installation#:~:text=Installers shouldn't automatically expect,the pipes reach maximum expansion.

Edited August 27 by JohnMo

[Dave Jones]

3 hours ago, Gaf said:

 - there is a barrier running all around between the screed and block work.

 

 

 

expansion tape, surprising how big the losses will be having no thermal break between screed and internal walls.

[Gaf]

On 27/08/2024 at 11:48, Dave Jones said:

 

expansion tape, surprising how big the losses will be having no thermal break between screed and internal walls.

 

Novice at this. When I google expansion tape related to UFH and screed, I'm finding a lot of references to the tape also acting as an insulation. Is that just marketing? The external walls had 25mm PIR all around.

 

Also, genuinely curious, when I was looking into the insulation options (EWI, IWI, CWI) there seemed to be a lot of views pointing at staying away from IWI because it prevented the blockwork from absorbing heat and releasing it back into the house. I may have gotten the complete wrong end of the stick on that though. I know heat rises but is it that without a proper thermal barrier, the internal blockwork at the ground level will be particularly cold due to it connecting down into the foundations so it takes away the heat and some will dissipate downward, so is just wasted energy?

 

Sweet F all I can do at this stage. Don't think builder was pulling a fast one on this as he sent me full plan pictures of the UFH before the screed was applied and it clearly shows the PIR on the external wall and the expansion tape on the internal ones.

[crispy_wafer]

25mm PIR at the perimeter is OK, some have more, some have none but the expansion strip.  It's fine, move on, focus on getting the ufh pipe repaired to a good standard,  tested, and replacing any displaced or missing perimeter PIR, then move onto the next challenge.

[Andehh]

8 minutes ago, crispy_wafer said:

25mm PIR at the perimeter is OK, some have more, some have none but the expansion strip.  It's fine, move on, focus on getting the ufh pipe repaired to a good standard,  tested, and replacing any displaced or missing perimeter PIR, then move onto the next challenge.

Well said!

[Jilly]

Yep, there’s always something…

[Gaf]

23 hours ago, crispy_wafer said:

25mm PIR at the perimeter is OK, some have more, some have none but the expansion strip.  It's fine, move on, focus on getting the ufh pipe repaired to a good standard,  tested, and replacing any displaced or missing perimeter PIR, then move onto the next challenge.

 

Yeah 100%. Half surprised and half not anymore with how much we have to keep an eye on things. Even the architect put in the wrong windows - only for it was caught we wouldn't have met fire regulations for final sign off...

 

The PIR and tape is also up against thermal blocks that run around the whole perimeter and on all internal block walls - so 25mm PIR + a thermal block. Be good enough for us.