Soldered pipe under floorboards

marfulee · Post by **marfulee** » Thu Sep 20, 2007 7:42 pm

As part of the bathroom refit, I switched the bath taps from one side to the other, so shortened the pipes. Since then, I've replaced floorboards, installed the bath (all screwed down), tiled around the bath, soldered pipes to the taps. The laminate floor is down and the bathroom is mostly finished.

But of course when I turn the water on, I hear a dripping noise and I can't see the leak. Of course I can't, it's the elbow under the floorboards! Sure enough I poke a hole in the ceiling down stairs and sure enough water drips out.

Looks like I'll be pulling up the carpet and ripping out the floorboard in the hallway, because I'm not about the try pulling the bath out!

That'll teach me not to test the joints before I cover them up! The pipes were a bit wet when I soldered them, so it wasn't easy, clearly wasn't sealed on the underside...

Jaeger_S2k · Post by **Jaeger_S2k** » Fri Sep 21, 2007 12:17 am

Wasn't easy? Was impossible!

Wet pipes can't be soldered!

The water boils off and takes away all the heat from the joint.

Solder melts at 180-190°C water boils at 100°C you saw solder running round the pipe at 180°C and it met a cool area of pipe and stopped because the water boiling was taking away your heat.

You'll now have very wet pipes and if you cannot get them dry inside and out, use heat if need be, if you can't then get 2 x 15mm Speedfit straight couplings a piece of speedfit 15mm pipe bendy stuff, find a local plumber and beg some, you'll also need 2 x 15mm inserts for the Speedfit pipe side of the coupling, open the ceiling a bit more where you already have and cut out the elbow with a pipe slice and fit the Speedfit.

There will be other ways but that seems simplest to me

Post by **ultimatehandyman** » Fri Sep 21, 2007 8:03 am

Nightmare!

You are sure that the tap connectors aren't leaking aren't you?

I have seen the washer fail in the tap connectors and the water run down the pipes and then drip off about 8 feet away from the taps.

Hoovie · Post by **Hoovie** » Fri Sep 21, 2007 10:44 am

Question - mostly to Jaeger 2SK, but anyone could chip in

.

In marfulees situation, he cannot use solder joints due to water still in pipe and suggestion was Speedfit.

Is there a rule of thumb in this situation on when to use Speedfit, and when to use Compression joints (or maybe when to use brass pushfit even?)

Opinions of long-term reliability for a joint that you REALLY do not want to ever have to work on again!?

Jaeger_S2k · Post by **Jaeger_S2k** » Fri Sep 21, 2007 10:58 am

Each situation has different solutions, Hoovie.

I'm suggesting Speedfit on this one as he'll have restricted access working through a hole in the ceiling making compression more difficult. It's also less technical a fitting and more chance of success as it will be in some ways unsighted.

It's very difficult to even say what my preferred order of fittings would be as each install has it's problems/issues that need to be overcome but end fed is tidier and I know of joints I made over 20 years ago that are still sound, compression is a kind of belts and braces fitting the pipe will corrode before a well fitted compression coupling will give but it's bulky and requires access for 2 wrenches, Speedfit is very flexible, access only required for push/pull (but the pipe should still be marked to ensure you've got full entry into coupling) again bulkier than end fed.

Then you've got Gas or Water to consider?

I'd struggle to say my order of fitting preference but I can say I fit more end fed than anything else.

Hoovie · Post by **Hoovie** » Fri Sep 21, 2007 11:16 am

Reasonable enough (I asked as I had a near identical sitution last thursday - had to redo a CH joint under floor due to repositioning bathroom rad and the bloody boards nearly caught fire as trying so long to solder a yorkshire coupling (water kept dripping down inside pipe

)
Joint was also under partition wall so limited access to see what was going on

I ended up using a standard compression joint for the sole reason that was all I had in my box and was able to reach in enough to work it.

Sounds like it is probably worth having a little variety of connectors "in stock" to suit different maintenance jobs (I did actually go out and buy a couple of speedfits next day in case the joint I made turned out to be no good and needed a quick fix)

Just reread the issue again and your suggestion about using speedfit connections and flexible pipe makes good sense

(hadn't initially picked up in my head about maybe not just as easy as swapping one connection for another)

marfulee · Post by **marfulee** » Fri Sep 21, 2007 11:36 am

When I say wet, I don't mean it was full of water, just a slight residue. I think it soldered OK on the top, but I didn't inspect the bottom half. The hot pipe was tested before the floorboards went back on, but the cold one wasn't as it had its own valve in the airing cupboard.

I was definitely having an afternoon of crap soldering, I managed to screw up another couple of pipes that I diverted to make room for some battening that was added for the replacement floorboards... All due to wet pipes. I'd only done new pipes before that!

Pulling up floorboard is marginally easier than ripping out and fixing the ceiling - but only because I'll be avoiding the earache from the wife for making a visible mark on the ceiling!

I read somewhere that you can plug a dripping pipe with a lump of fresh bread, the idea being that it'll disintegrate when you switch the water back on after soldering.

Failing that, I might invest in a MAPP blow torch

marfulee · Post by **marfulee** » Fri Sep 21, 2007 11:40 am

Jaeger_S2k wrote:Wasn't easy? Was impossible!

Wet pipes can't be soldered!

The water boils off and takes away all the heat from the joint.

Solder melts at 180-190°C water boils at 100°C you saw solder running round the pipe at 180°C and it met a cool area of pipe and stopped because the water boiling was taking away your heat.

You'll now have very wet pipes and if you cannot get them dry inside and out, use heat if need be, if you can't then get 2 x 15mm Speedfit straight couplings a piece of speedfit 15mm pipe bendy stuff, find a local plumber and beg some, you'll also need 2 x 15mm inserts for the Speedfit pipe side of the coupling, open the ceiling a bit more where you already have and cut out the elbow with a pipe slice and fit the Speedfit.

There will be other ways but that seems simplest to me

I'm quite tempted to just get a 900mm long speedfit tap connector, that should reach straight to the tap if I manage to get to the pipe with the pipe slice.

marfulee · Post by **marfulee** » Fri Sep 21, 2007 11:47 am

ultimatehandyman wrote:Nightmare!

You are sure that the tap connectors aren't leaking aren't you?

I have seen the washer fail in the tap connectors and the water run down the pipes and then drip off about 8 feet away from the taps.

Yes, definitely not the tap connectors: I cut out the pipes above the floorboards and slapped a pushfit stopend on it and it was still leaking...

Hoovie · Post by **Hoovie** » Fri Sep 21, 2007 11:56 am

marfulee wrote:When I say wet, I don't mean it was full of water, just a slight residue. I think it soldered OK on the top, but I didn't inspect the bottom half. The hot pipe was tested before the floorboards went back on, but the cold one wasn't as it had its own valve in the airing cupboard.

I was definitely having an afternoon of crap soldering, I managed to screw up another couple of pipes that I diverted to make room for some battening that was added for the replacement floorboards... All due to wet pipes. I'd only done new pipes before that!

Pulling up floorboard is marginally easier than ripping out and fixing the ceiling - but only because I'll be avoiding the earache from the wife for making a visible mark on the ceiling!

I read somewhere that you can plug a dripping pipe with a lump of fresh bread, the idea being that it'll disintegrate when you switch the water back on after soldering.

Failing that, I might invest in a MAPP blow torch

I am also doing a similar peice of work to you right now - redoing bath, tiling, pipework, etc so fully symphasise with your problems.

The fresh bread thing - yes, white hovis is favourite from what I hear !

never done it myself, but I hear it is a great way to soak up the water while you are redoing a pipe - I would think that this is only applicable to water (as opposed to Central Heating) as the bread will come out the tap in tiny bits, but in heating pipes would stay around the heating system and maybe cause problems (dunno, just my logic

)

Jaeger_S2k · Post by **Jaeger_S2k** » Fri Sep 21, 2007 12:04 pm

... and when I say wet pipes can't be soldered I don't mean full of water either.

Your other 'failed' solder joints are testimony to it, wet pipes can't be soldered.

Oh and good luck with the Mapp, it won't help, really, really, really, really really hot wet pipes cannot be soldered either.

It will help if you fancy doing some brazing work though.

Let's clear this up then, WET PIPES CANNOT BE SOLDERED!

I only do dry pipes.

Unless you know how too but that's a long story and as a general rule to follow which will save you hours of pain and rebuilding/refitting if the pipes wet don't solder it. Use a compression or Speedfit.

Hoovie · Post by **Hoovie** » Fri Sep 21, 2007 12:10 pm

Jaeger_S2k wrote:... wet pipes can't be soldered.

....., really, really, really, really really hot wet pipes cannot be soldered either

.......Let's clear this up then, WET PIPES CANNOT BE SOLDERED!

stop sitting on the fence - what do you REALLY think?

Jaeger_S2k · Post by **Jaeger_S2k** » Fri Sep 21, 2007 12:12 pm

marfulee · Post by **marfulee** » Fri Sep 21, 2007 2:28 pm

White Hovis it is then! I don't think I'd fancy leaving bits of bread in the central heating system, I guess it'd be OK if you did a power flush. I found I had to prop the pipes up to get the water to drain away from the pipes... What do the pros do?

I know the guys who fitted my in-laws' solar panels used a compression joint to tap into the mains water for the filling loop - they didn't tighten it up and caused a leak and means that they need a new ceiling. I don't think I'd want a compression join under the floor! I'll go with a soldered joint and make sure I don't **** it up!

Hinton Heating · Post by **Hinton Heating** » Fri Sep 21, 2007 4:48 pm

no dont put bread in central heating pipes.!

You could try lifting the joint to be soldered so that the water runs back into the slightly lower hoizontial bit.

sometimes the heat from a blowlamp will dry the pipe enougth to make the joint, but experiance will tell you if the joint has worked or not.

I also sometimes blow the water back up pipes, to help prevent the constant wetting of a joint, by using a small hose, and a healthy pair of lungs.

You should put compression joints under the floor, even tho i've found some really old ones under floors before, which are sound.