IS my Under Floor Heating installation ruined ?

[nhg66]

Hi,

I am in the process of having an extension built that incorporates UFH totaling 75 sq meters set into 5 zones. This was installed a couple of weeks ago on top of 75mm Kingspan then screeded over with 80mm. The plumber pressure tested the UFH zones and left the system pressurized. The room where this was installed was open to the elements as the glazing has not been installed. Since this time we have had some severe frosts and on Wednesday this week the main contractor spotted that the UFH pressure had fallen to zero. They topped it back up and noticed pretty much straight away that water was seeping through screed in two places within the same zone. The chopped holes in the screed and found the split pipes and replaced them with new sections jointed with some type of joint supplied by the supplier. They then re screeded the holes.

I found out about this yesterday when I returned from working away. The affected pipe was returned to the suppliers for the attention of the company rep who said immediately that the damage was due to frost. I also noticed that two of the pipes at the manifold had prominent bulges just below where they connect into the manifold.

Can anybody advise me what is best course of remedial action as I now do not think this installation can have the same integrity as a brand new system out the box that has not been subject to frost. Whilst I do not want the delays associated with ripping up 10 tonnes of screed and having to re do the installation (builders cost and time) I do not trust them just doing a pressure test. They suggest pumping up to 3 bar and checking for leaks.

Over to you guys for advice and guidance. FYI, I have a very good relationship with the main contractor.

 

[JohnD]

risk assessment:

Probability of an unseen fault arising later: unknown

Severity of impact once your house is finished, occupied and carpeted: enormous

so I would dig it up

 

[Norcon]

This is where pneumatic testing would have been a saviour.

What system is installed? What make of pipe?
It certainly needs testing to the limit of what the MI's recommend.
If it was mine I'd rip it out and forget testing at this stage.

 

[DeltaT2]

Deffo the Plumbers fault, you'd never pressure test UFH with H2o if there's a risk of frost. But you or the Builder are also to blame for employing the services of some dafty that's not got a clue about UFH!! Cheap was he??!!
Well, he's not cheap now is he???......LOL!!

Air pressure tested on new builds during Winter Months.

 

[doitall]

You should never air test underfloor heating.

The fault lies with the builder for no protecting the floor or pipework.

If the frost was that bad the screed is probably shattered anyway.

 

[nhg66]

Deffo the Plumbers fault, you'd never pressure test UFH with H2o if there's a risk of frost. But you or the Builder are also to blame for employing the services of some dafty that's not got a clue about UFH!! Cheap was he??!!
Well, he's not cheap now is he???......LOL!!

Air pressure tested on new builds during Winter Months.

If you are so clever, how come another poster said never test UFH with air ???

 

[DeltaT2]

Deffo the Plumbers fault, you'd never pressure test UFH with H2o if there's a risk of frost. But you or the Builder are also to blame for employing the services of some dafty that's not got a clue about UFH!! Cheap was he??!!
Well, he's not cheap now is he???......LOL!!

Air pressure tested on new builds during Winter Months.

If you are so clever, how come another poster said never test UFH with air ???

Well, you did ask!! Of course it'll cost you a lot, mainly as a result of lost time on the build. The cowboy builders(so it was him that got the cheap price?!!) will need to lift the whole concrete floor & start again!! If the UFH pipes burst in the screed then the pipes are not embedded enough. It's a complete shambles!!

 

[DeltaT2]

Sorry to disagree, but we air test UFH pipes in Winter all the time. It's the only way we can in Scotland.

 

[doitall]

Sorry to disagree, but we air test UFH pipes in Winter all the time. It's the only way we can in Scotland.

You are allowed to mate. But it's still bad practice.

It's not that difficult to protect the pipes from freezing, as you have to protect the screed anyway.

 

[nhg66]

Guys,

I accept that to replace the whole screed and pipework etc will be costly but this is down to the main contractor. His work is very good, has been complemented by a lot of my friends who are associated with the building trades and the plumber he uses has been working for him for years. I guess he may not of installed UFH in the winter but who knows. It clearly states in the installation bumph that comes with the UFH that you should not install in likely frost conditions or if you do to not wet the system and to leave the valve vents open. I do genuinely believe this was a mistake and I am not seeking to apportion blame and fall out with my builder BUT I do need peace of mind that if it were to stay in then it must be perfect. Clearly from all of the posts it is NOT and therefore I will have to instruct that all of screed and all 5 zones come up and get refitted.

I was there when the pipes were fitted and the screed laid and they were fitted correctly as far as I could see, all clipped down against the Kingspan then the screed on top which I also saw and can vouch that it was 80-90mm deep.

Many thanks for all of the advice but if anyone thinks re-doing the job is over reacting then please pipe up with reasons why.

FWIW, the glazing comes next week so any refit can be done in a sealed room where I can then employ some convector heaters to protect against frost.

 

[Dan Robinson]

certainly not overreacting IMHO.

 

[Corgigrouch]

Ditto... Pull it up and re do...... I would never regard a repair joint in screed anything other than a leak looking for somewhere to happen..

 

[Norcon]

It's a harsh lesson.
About 3 tight men should have it out in a day and maybe quicker starting at the opposide side to the exits. Two jack hammers with around 25 joules of impact energy each and a wheel barrow or two.
About 16-18 ton to shift. Nice.

 

[SimonH2]

You should never air test underfloor heating.

I'm curious - why not ? Not arguing or suggesting you are wrong, just curious as to why since I can't think of a logical reason why not (it'll probably be something really obvious after writing that )

 

[mysteryman]

I agree, you need to get it ripped up and replaced, and a new screed laid.