Threading Old 3/4" Steel Pipe Tight To A Wall.

[Catherine1]

Hi

I'm looking to have some pipework altered underneath the kitchen sink. There is some 3/4" steel pipe coming up from below the floor which I need shortening to allow for a deep Belfast sink and quite a thick timber worktop. Plus all the adjoining pipework is leaking and needs replacing. I've spoken to two plumbers and they have said that the pipe would ideally need to be cut down and threaded in order for it to be lowered and attached to any new pipework. However because it is tight to the wall they said this would be very tricky. One suggested breaking out the surrounding concrete floor to get to the underground joint, to put a whole new pipe in, which we have done but now the other one said this would be risky because if it all goes wrong the local water authorities would need to come out and carry out major works to put it right! But he also said it was an unusual job and was unsure how to go about it. Well if two experienced plumbers don't know then I'm pretty sure I don't... I'm hoping someone on here will know and be able to suggest an answer. Please see attached photos.

Many thanks in advance.

Catherine

 

[ShaunCorbs]

TBH looks fine to me and not a bad job

If that's a joint just below the floor even easier

Just needs someone capable to do the works

More of the floor would need to be broken up for access but other than that should be fine

 

[Catherine1]

Thanks Shaun. Will that underfloor joint be threaded or just pushed in and soldered? He said he was worried that when trying to remove it it would break off...

 

[ShaunCorbs]

Thanks Shaun. Will that underfloor joint be threaded or just pushed in and soldered? He said he was worried that when trying to remove it it would break off...

Female Threaded, looks like there's a coupling take the top pipe out and install a 1/2 male iron to copper

And if it's going to break very unlikely but it's time for a change as chances are it's already leaking

 

[Catherine1]

Ok thanks. I wondered if there was such a thing whereby you could cut the pipe down to the required level and push on and solder a threaded fitting/adaptor?

 

[ShaunCorbs]

Ok thanks. I wondered if there was such a thing whereby you could cut the pipe down to the required level and push on and solder a threaded fitting/adaptor?

No sorry there are compression but there bulky

 

[Catherine1]

I guess it would depend how bulky. The pipe isn't touching the wall where it needs to be cut down to. I can get my fingers behind it and there is a bit of give to pull it away slightly.

 

[ShaunCorbs]

PRIMOFIT - Georg Fischer Fittings GmbH

 

[Catherine1]

Great thanks for your help. I'll show my plumber and see what he says.

 

[Chalked]

As Shaun mentions. Hold onto the socket underground, cut the elbow off the pipe at the top and unscrew it will be either 1/2, or 3/4 bsp adapters are easily available. You may need an older plumber! Anyone under 40, won't have much experience with galvanised steel.

 

[gmartine]

Make sure you can turn off the supply at your outside stop valve before carrying out any work. That underground coupling looks pretty corroded to me and I couldn't be sure of getting that apart intact...you guys seem quite sure about that? If not dig down around the pipe as far as you possibly can that should allow the pipe to come away from the wall once it is cut (say 6inches above the floor) and allow enough access for a new thread to be cut even if you have to bend it a little. You could certainly start feeding that coupling penetrating oil, that'll give you the best chance of it coming apart.

 

[ShaunCorbs]

Make sure you can turn off the supply at your outside stop valve before carrying out any work. That underground coupling looks pretty corroded to me and I couldn't be sure of getting that apart intact...you guys seem quite sure about that? If not dig down around the pipe as far as you possibly can that should allow the pipe to come away from the wall once it is cut (say 6inches above the floor) and allow enough access for a new thread to be cut even if you have to bend it a little. You could certainly start feeding that coupling penetrating oil, that'll give you the best chance of it coming apart.

Yep little bit of heat and your golden

 

[quality]

it will need a bit more than a little bit of heat as it will be full of water but with heat it will come apart no probs

 

[ShaunCorbs]

it will need a bit more than a little bit of heat as it will be full of water but with heat it will come apart no probs

Drain the water out of it first

 

[quality]

We know but sounds like those who have looked had this little job may not know

 

[jtsplumbing]

This is basic Plumbing for anyone that knows what they are doing ! Don't they teach anything anymore ? FFS if it not push fit they cant do it, what as happened to all the skills this job used to need ??

 

[leelister6]

This is basic Plumbing for anyone that knows what they are doing ! Don't they teach anything anymore ? FFS if it not push fit they cant do it, what as happened to all the skills this job used to need ??

Totally agree! Was doing a new build a couple of years ago and clients nephew was doing a bit of labouring during a break from college on a plumbing course and didn't take a bit of interest in what I was doing. 30 years of experience to draw on and didn't ask one question! Anyway back to the problem in hand, pair of 18" Stilsons and a bit of heat on the socket and it'll p155 off then female iron to copper onto thread, 15mm copper into that then wrap in Denso to ground level and gobbo back up. Hours job!

 

[Ric2013]

Low-carbon steel pipework and bending is still on City and Guilds level 2 syllabus. I was the one most interested in it as if I ever move to Italy there's loads of steel still in use in Italy. One of my classmates used steel every day at work- he worked for a comapny doing commercial heating.

 

[jtsplumbing]

Low-carbon steel pipework and bending is still on City and Guilds level 2 syllabus. I was the one most interested in it as if I ever move to Italy there's loads of steel still in use in Italy. One of my classmates used steel every day at work- he worked for a comapny doing commercial heating.

Yes I understand what your are saying ! But the new guys on the block don't seem to have much of a clue, hence my comment ! it may just be me But unless its push fit or a combi they seem to come unstuck, where will all the old skills be in another 20 years, Plumbing used to cover so meny different things, Lead & Copper roofing, cast drainage, steel pipe, even glazing was the plumbers job, Now they seem to struggle with some pretty basic tasks.

 

[Ric2013]

JTS - agreed. In fact, I was pulling my teacher up on some of the bends she was accepting claiming I was unhappy with the way the pulled 90s (mine especially) were almost folding. She claimed that's just how it was coming up and I argued that if I plumber did that work in my house I would find it unacceptable and surely we're missing some knowledge. Then the assessor walked in, took my side of the debate, and showed us how to do it properly.

We were also told cast iron rainwater pipe is really brittle and this makes it very difficult to drill and cut (and, of course, there is no C.I. practical on the syllabus). My own experience does not support this theory that C.I. is hard to drill or cut.

Steel'll go out of the syllabus too, soon, I expect .

 

[ShaunCorbs]

it can be ric normally the last few mm if you push to hard a chunk will come with the plug its made of rubbish stuff and can have air bubbles in

 

[Ric2013]

Oh, yes, I agree it's variable and not a uniform material, especially the old stuff. What I meant was that that the teacher seemed to think it was almost a trade in itself beyond us general plumbers requiring specialist equipment to cut and drill and I'd say pulling a passover accurately was a harder skill to learn. She more-or-less talked one of us out of taking on any job involving C.I. (and he had general skills far better than mine). I cut iron with a fine metal cutting disc on a grinder and drill it with a HSS drill bit on a cordless drill (with the torque set down to avoid cracking it if it catches).

I'd already installed 35 metres of the stuff (about half of that was second-hand and made of 5' bits cut off from the split 6' lengths) before I took my plumbing course and not had any real problems (apart from putting a 1:40 fall on some of it due to a typo in the 1969 Readers Digest DIY Manual and one split I hadn't noticed in one of the old bits). When my PVC next breaks, I have some more C.I. in my loft (off a mate's house) to replace it with.

The main problem I had was using bitumen mastic as a jointing compound (in spite of the manufacturer claiming suitability and the fact that the mastic was proper stuff, containing asbestos). I had success with 'dry glaze' rubber strips (designed for windows, but I wasn't paying out (for my own house) for the proprietary C.I. rubber gutter seals, not at the rip-off price I was quoted), but last lot I fitted was a year ago and I just used putty, and I think it's the best way.

 

[Ric2013]

OP: If you're stuck, try a company that deals with commercial heating - they use low carbon steel pipework a lot and would be tooled up and experienced with this material.

 

[ShaunCorbs]

has the op said where she is ? / where are you in the lovely work op

 

[ShaunCorbs]

cant pull a bend with cast iron

 

[jtsplumbing]

Oh, yes, I agree it's variable and not a uniform material, especially the old stuff. What I meant was that that the teacher seemed to think it was almost a trade in itself beyond us general plumbers requiring specialist equipment to cut and drill and I'd say pulling a passover accurately was a harder skill to learn. She more-or-less talked one of us out of taking on any job involving C.I. (and he had general skills far better than mine). I cut iron with a fine metal cutting disc on a grinder and drill it with a HSS drill bit on a cordless drill (with the torque set down to avoid cracking it if it catches).

I'd already installed 35 metres of the stuff (about half of that was second-hand and made of 5' bits cut off from the split 6' lengths) before I took my plumbing course and not had any real problems (apart from putting a 1:40 fall on some of it due to a typo in the 1969 Readers Digest DIY Manual and one split I hadn't noticed in one of the old bits). When my PVC next breaks, I have some more C.I. in my loft (off a mate's house) to replace it with.

The main problem I had was using bitumen mastic as a jointing compound (in spite of the manufacturer claiming suitability and the fact that the mastic was proper stuff, containing asbestos). I had success with 'dry glaze' rubber strips (designed for windows, but I wasn't paying out (for my own house) for the proprietary C.I. rubber gutter seals, not at the rip-off price I was quoted), but last lot I fitted was a year ago and I just used putty, and I think it's the best way.

If your interested in old skills look on eBay I got 2 sets of Plumbing books dating back to the 1930s show's all the old methods of doing things interesting how a lot of things haven't changed , even sections on gas ,I find the old photos of how cookers & fires & boilers were back then are good to look at

 

[Michael1960]

Philmac make a transitional coupling LCS to copper (or anything else)

 

[Ric2013]

cant pull a bend with cast iron

I didn't mean in cast iron. I meant pulling a passover in copper

 

[ShaunCorbs]

I didn't mean in cast iron. I meant pulling a passover in copper

sorry

and agree most of what they teach these days is plastic / pushfit

 

[Ric2013]

We weren't really taught plastic, we were just talked through it and told to do the assessments. Perhaps that's why I hate the stuff so much? (And fitting a towel rail today, trying to hide the poxy stuff under a fake pipe shroud that probably cost more than just using a bit of chromed copper in the first place grr.)

 

[ShaunCorbs]

We weren't really taught plastic, we were just talked through it and told to do the assessments. Perhaps that's why I hate the stuff so much? (And fitting a towel rail today, trying to hide the poxy stuff under a fake pipe shroud that probably cost more than just using a bit of chromed copper in the first place grr.)

Same and never use the stuff unless dier emergency eg threading through joists (holes) but then I tend to use mlcp if I can

The trades loosing skill every 10 years and nothing new is being picked up / learnt that is good

 

[Ric2013]

You'll appreciate these basin runs then (microbore a bit naff, but it was the first time I ever used the stuff)

 

[ShaunCorbs]

You'll appreciate these basin runs then (microbore a bit naff, but it was the first time I ever used the stuff)

View attachment 30823

Better than plastic and looks great

 

[Ric2013]

Well, there was no plastic in that house and I didn't want to be the one to add it. Used a bit in the loft, but all accessible and visible.

 

[Catherine1]

Thanks all for your input, sorry for late response. The Philmac transition couplings mentioned are plastic. Would that be OK to use? I tried twice contacting the company who makes the primofit ones for more info but they never got back to me.

 

[ShaunCorbs]

Yes would be fine

 

[Catherine1]

Thanks Shaun. Seemed plastic was getting a bit of a bad press that was all...

 

[ShaunCorbs]

Thanks Shaun. Seemed plastic was getting a bit of a bad press that was all...

It's ok depends what you can get hold of

but I would take the piece out the coupling and put a male iron in but that's me

 

[Michael1960]

Thanks all for your input, sorry for late response. The Philmac transition couplings mentioned are plastic. Would that be OK to use? I tried twice contacting the company who makes the primofit ones for more info but they never got back to me.

The Philmac couplings are excellent, they look bulky and are obviously used out of sight. You can come off of them in any material you just need the correct adaptor. Any decent plumbers merchants will advise you. I have cut out a lot of LCS in old council houses where its on the hot and cold water supply! Simply fit a Philmac and then your away in nice new copper.

 

[Catherine1]

Thanks both!

 

[Michael1960]

Thanks both!

Philmac MDPE Universal Transition Coupling | Philmac MDPE Universal Transition Coupler 15-21mm X 20mm | City Irrigation Ltd

 

[moonlight]

Cut a section of iron pipe off, drop in small hose through open pipe. Siphon water out. Hold bottom elbow, heat pipework and unscrew. Fit new male iron to copper fitting sorted. Just make sure you protect the copper in the ground with insulation.

 

[Ric2013]

Philmac should be okay for cold water, not suitable for hot.