qual-pex pipe replacement concrete floor

na1

Folks,
I have a suspected burst/damaged pipe (plastic qual-pex) buried into concrete flooring on the ground floor.
The pipe itself is not in a concrete it is in a so-called 'pipe-in-pipe' - the black high density polyethylene pipe.
Which is according to the description I found on the web:

has been designed to help the installer comply with the current water regulations. Please note that regulations may state that pipes installed within solid floors should be able to be withdrawn and replaced if necessary'

So I'm wondering how feasible would it actually to withdraw the pipe and replace it with a new one without cutting out the concrete?
I'm not going to do it myself, but rather get a plumber help.
It doesn't seem to be a very common kind of work. If anyone have this experience, or even can suggest the company to do this?
I'm in Cork area.

Outkast_IRE

na1 wrote: »

Folks,
I have a suspected burst/damaged pipe (plastic qual-pex) buried into concrete flooring on the ground floor.
The pipe itself is not in a concrete it is in a so-called 'pipe-in-pipe' - the black high density polyethylene pipe.
Which is according to the description I found on the web:



So I'm wondering how feasible would it actually to withdraw the pipe and replace it with a new one without cutting out the concrete?
I'm not going to do it myself, but rather get a plumber help.
It doesn't seem to be a very common kind of work. If anyone have this experience, or even can suggest the company to do this?
I'm in Cork area.

Its certainly possible, but it gets more difficult with the longer the run and if there are many bends or turns in the route the pipe takes. I would certainly give it a shot before digging up floors. Obviously it wont work if there are any joints on the pipe underground.

na1

I doubt it has joints, though it can have bends of course.

Yes I'm not going to try this unless I'm 100% confident, because even if I able to extract the old pipe there is no guarantee that I can manage to put the new pipe in place)) There must be some techniques like attaching the new pipe to the end of the old pipe and extract-replace the pipes in one go?
That's why I'm looking for the experienced plumber who has done this job many times))

Another challenge is to find the other end of the pipe as I have 5 rads downstairs, and it could be any of them and any pipe (in or out)

Calahonda52

what makes u think its burst/damaged?
How long has this been happening?
Did some one drive a nail through it..?

some blue sky stuff here:)
If its in a sleeve then the water will only appear at each end so the starting point might be to find the ends?
depending on the wall thickness of the HDPP the qual-plex might be already a snug fit and it it is my guess it won't pull out
The pipe within a pipe may only be at each end where it is visible....:)

na1

Calahonda52 wrote: »

what makes u think its burst/damaged?
How long has this been happening?

there is a dump spot on the concrete floor in the utility room (thanks God it is not tiled!) just next to the boiler.
The water is not coming from the boiler, and all the pipes under the boiler are dry.

I'm not 100% sure it is a burst pipe, I even not sure if it is a radiator pipe or some other pipe in a system which passes under the floor.
There is also a washing machine PVC waste pipe which goes somewhere nearby...

The tricky part is that the dampness is very intermittent. It can appear once and dry out and don't appear for a wile.

I even haven't associate the time when it appears - with the time I use the heating or washing machine - it is not happening regularly....

If its in a sleeve then the water will only appear at each end so the starting point might be to find the ends?

Good point, the water is pouring through the concrete, not at the end of the pipe, Originally I even suspected that it is a rain water entering the house in the gap between a wall and the flooring - there are some cavities in the walls for copper pipes going in and out of the boiler.
But lately didn't find any trace of dampness close to the wall.

The pipe within a pipe may only be at each end where it is visible....

I changed one of the rads recently and was able to pull the pipe a little bit and push it back. So at least the pipe is loose in the concrete...

Calahonda52

Are u losing pressure on the heating, even when it is off/cold
could be a joint that leaks when heated?
How do u heat ur water, maybe put 2 bar in it at cold and use immersion for a few days.
I had a similar type looking problem, eventually it was driving rain under the door saddle and under the plastic that was under the laminate floor, it took ages to resolve

na1

Calahonda52 wrote: »

Are u losing pressure on the heating, even when it is off/cold
could be a joint that leaks when heated?

How do I check for the water pressure on the heating? I'm not sure if I have a pressure meter in the hot press? Or where should it be?

As for the joints: unless there is a joint in the pipe under concrete - all other joints are not above the damp area and can't contribute to the leak.
Also most of the pipes are copper pipes - and I would notice a corrosion if there is a persistent leak, it is only the pipes that go into the concrete are plastic.

It is hard to explain without a picture, there is a pit in the concrete floor where the boiler and most of the pipes are: so if any of these pipes leak the water will go below the floor level - and I wouldn't have a damp spot on the floor. It is only the quap-pex pipes which go to and from radiators - that are inside the concrete.

Another thing is that qual-pex pipes are quite solid and hard to get damaged when in concrete, so my other suspect is a PVC 40 mm waste pipe which have possibly cracked when the foundation of the house has settled, there are actually tiny cracks in the concrete near this area...

Calahonda52

Have u no pressure gauge anywhere on the system with a top up loop?

maybe its an open system, how many water tanks in attic?

agusta

sounds like it could be the 40mm waste pipe to me.It seems to only get damp intermittently.Can you see the 40mm washing machine waste pipe exiting the outside of the house above the footpath..

na1

Did some investigations last night and think I found the problem!

I tried to exclude all other possibilities like waste pipe, leaks from some other area/or from outside - when water just pours from the cracks between a wall and the floor etc.
Started from checking the rain-water scenario:
while splashing few buckets of water on the outside wall, I noticed the boiler exhaust pipe on the wall.
I have the gas boiler mounted on the wall in the utility room close to the place where the dump area was
And the exhaust pipe is going through the wall to the outside.
Splashed some water just above the pipe (the boiler was off!) and immediately saw the water dripping from the edge of the boiler inside. The place where the water was dripping was close to the place where the damp area was.
I left it for several minutes and then (due to small incline on the floor) noticed that the water was accumulated in the original dump area!

So now I'm almost confident that during heavy rain against that wall the water enters the combustion chamber on the boiler through the exhaust pipe and then dripping from the boiler to the floor inside...
To prove it I'll put some film on the floor below and will check it during the rain.
I assume this is only happening during heavy rain when the wind is blowing towards that wall...

K.Flyer

na1 wrote: »

Did some investigations last night and think I found the problem!
[...]
So now I'm almost confident that during heavy rain against that wall the water enters the combustion chamber on the boiler through the exhaust pipe and then dripping from the boiler to the floor inside...
To prove it I'll put some film on the floor below and will check it during the rain.
I assume this is only happening during heavy rain when the wind is blowing towards that wall...

What is the make and model of your boiler?

na1

K.Flyer wrote: »

What is the make and model of your boiler?

I don't know need to check when get home....

Is it about this thread?))
http://www.boards.ie/vbulletin/showthread.php?t=2055775716


I'd say it is more the question who installed it, because when properly following the installation guide the boilers should be rain proof))

na1

It is Ferroli sys 10-23

K.Flyer

Best to get an RGI out to check over the internals of the boiler for internal corrosion from water damage. He will also be able to see how the water is getting into the boiler and work out the best course of action to rectify the problem.

na1

Thanks!
I do service my boiler annually (last serviced Jan 2015), the guy who serviced it haven't find anything. although at that time I wasn't aware about the leak, so didn't ask to look specifically for the corrosion. BTW: water is one of the products of the gas burning, so the gas chamber must be designed to handle the high temp water steam.

Dtp1979

na1 wrote: »

Thanks!
I do service my boiler annually (last serviced Jan 2015), the guy who serviced it haven't find anything. although at that time I wasn't aware about the leak, so didn't ask to look specifically for the corrosion. BTW: water is one of the products of the gas burning, so the gas chamber must be designed to handle the high temp water steam.

No not those boilers and certainly not like that. The water and flame don't come in contact.

na1

The heated water - yes, but the burning gas itself produces some amount of water (water vapour) which can condensate in the chamber.

K.Flyer

na1 wrote: »

The heated water - yes, but the burning gas itself produces some amount of water (water vapour) which can condensate in the chamber.

Unless it's a condensing boiler designed to handle condensate then the corrosive nature of condensate can rot the inside of the combustion chamber.