IS my Under Floor Heating installation ruined ?

[dcawkwell]

Another success story of underfloor heating.
Wouldn't got near the stuff myself.

It does make you wonder about the sanity of the heating engineer
testing a system in a house without windows or working
heating system in WINTER!!!

My suggestion would be pressure test the individual circuits
and keep any that are good. Any that aren't install good old
radiators.

 

[doitall]

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 )

Air compresses, so the pipe will expand and make any joints tighter.

Therefore.

Any weeps won't show as the expanded pipe has made the seal tighter..

The pipe expanding can actually compress the O ring and cause leaks when the pressure is released.

Expanding the pipe can damage the wall.

Testing with air is dangerous, and at the very least you should post notice boards and clear the test area.

More. ?

 

[Agile]

I dont see any of those reasons which dont apply equally to pressure testing with water!

Nor do I see how the pipe can expand if encased in cured concrete.

Could it be that the concrete is also spoilt? It must be pretty poreous if it puddled by the leaks.

Tony

 

[JohnD]

in freezing conditions, concrete is slow to cure, and if frozen before curing, will be crumbly, weak and useless.

 

[Corgigrouch]

Air compresses unlike a liquid and so if when under test a joint lets go, if under test with water the pressure will drop virtually immediately limiting the force of the sudden depressurisation... if tested with air then if a joint or pipe fails then a large volume of air must come out before the pressure is at atmospheric pressure meaning that a lot more damage would be done, bits of pipe and fittings flying around... Not so important if the area under test can be isolated so that no one can wander near whilst under test but I believe it contravenes some pressure testing of pipework regs if the area cannot be isolated.... Having seen copper air conditioning pipes pop when tested with OFN they are a regulation worth taking notice of.... I'll let the anoraks dig the precise reg out..

 

[doitall]

I dont see any of those reasons which dont apply equally to pressure testing with water!

Nor do I see how the pipe can expand if encased in cured concrete.

Could it be that the concrete is also spoilt? It must be pretty poreous if it puddled by the leaks.

Tony

You can always smell a non installer a mile off.

Air compresses so you have 10 x more energy.

You test the pipework prior to screeding and leave it under test during screeding.

The concrete could well be spoilt, depends how many day it was laid before the frost hit it.

Puddles means it ain't very level Tony

 

[DeltaT2]

I dont see any of those reasons which dont apply equally to pressure testing with water!

Nor do I see how the pipe can expand if encased in cured concrete.

Could it be that the concrete is also spoilt? It must be pretty poreous if it puddled by the leaks.

Tony

You can always smell a non installer a mile off.

Air compresses so you have 10 x more energy.

You test the pipework prior to screeding and leave it under test during screeding.

The concrete could well be spoilt, depends how many day it was laid before the frost hit it.

Puddles means it ain't very level Tony

Sorry Tony, but I find DIA's reply funny.
Don't dwell on air pressure testing too long or you'll flush out 'Onetap', he'll go off on one!!!.........

Air testing is done with the pipe loops connected to the manifold, no other connections are in place & we've never had one 'blow' yet.

Concrete takes 20 years to go 'off', but it can handle frost if it's been down for a few days. Regardless, the Builder should not have poured concrete if there's any chance of frost. Does he not watch the weather forecast?? My mate lives in Engerland & he says everything ground to a halt with 1" of snow..............

 

[MJN]

Air compresses, so the pipe will expand and make any joints tighter.

Therefore. [...]

What a load of absolute nonsense. You're making this up.

Testing with air is dangerous, and at the very least you should post notice boards and clear the test area.

That bit's true. The only issue with using compressed air vs water is the stored energy of the former presenting a potentially serious hazard if anything should suddenly go.

Mathew

 

[doitall]

Air compresses, so the pipe will expand and make any joints tighter.

Therefore. [...]

What a load of absolute nonsense. You're making this up.

Testing with air is dangerous, and at the very least you should post notice boards and clear the test area.

That bit's true. The only issue with using compressed air vs water is the stored energy of the former presenting a potentially serious hazard if anything should suddenly go.

Mathew

I got a £1000.00 say it does and you don't know what you are talking about.

And it's very easy to prove.

Want to match it, we can do some tests with your compressor.

 

[MJN]

And it's very easy to prove.

I'm all ears.

 

[doitall]

Just stick 10m on the end of the compressor and blow it up to 6-10bar and measure the OD.

 

[MJN]

Just stick 10m on the end of the compressor and blow it up to 6-10bar and measure the OD.

...and do the same with water.

Note how the OD's are the same for both?

I am not for one moment disputing how much more dangerous performing a dry/air test compared with one using water, however to claim that there will be more pipe/joint expansion when using air at the same pressure as when using water is quite simply wrong.

Mathew

 

[SimonH2]

I am not for one moment disputing how much more dangerous performing a dry/air test compared with one using water, however to claim that there will be more pipe/joint expansion when using air at the same pressure as when using water is ridiculous.

Just what I was thinking.

The biggest advantage I can think of for wet testing is that the weight of the water will make the pipe less buoyant, and so it will be easier to keep it properly down while the screed is poured. But once the screed has set then that's not a consideration. Common sense suggests that if there's a risk of frost then you either need to empty the pipes (blow them out with air) or put antifreeze in. Blowing them out isn't guaranteed not to leave a low spot that the water will run to and still leave you with a section of pipe that's completely filled and liable to freeze damage.

It can't be an uncommon problem in winter - at least in some areas.

 

[doitall]

Just stick 10m on the end of the compressor and blow it up to 6-10bar and measure the OD.

...and do the same with water.

Note how the OD's are the same for both?

I am not for one moment disputing how much more dangerous performing a dry/air test compared with one using water, however to claim that there will be more pipe/joint expansion when using air at the same pressure as when using water is quite simply wrong.

Mathew

try it.

 

[MJN]

Why? You clearly haven't!

A pipe will expand in accordance with the force applied to it. Air at 10bar exerts the same force as water at 10bar ergo any expansion will be the same.

This is the plumbing equivalent of which is heavier, a ton of feathers or a ton of lead?

Mathew