leak from cold water tank, any advice?

[c r]

Hi

My ceilings started raining lastnight, an interesting experience I must say... Luckily I was at home, asleep in front of the t.v- the noise eventually woke me up, and so I was able to isolate the mains water pipe before too much damage had been done, and switch off the fuse to the lighting circuit (the lights were dripping & fizzing...). Lots of soggy carpets and a few very wet books- but could have been much much worse...

I have a cold water storage tank in the loft, which is absolutely where the water was coming from. I'm without a ladder at home at the moment, therefore I cant get up there to have a look, so I was just wondering what the likely causes of the leak are going to be? Given the cold weather at mo Im assuming its likely a burst pipe (its a copper mains), or are there a whole host of other problems that can occur with cold water tanks in the loft?

A few years ago we had a new copper feed plumbed up to the tank, but ive no idea of how well the pipe was lagged, or whether the tank itself is insulated. Have never had any trouble like this before, as far as I know I think its a fairly old tank and ballcock up there.

Well sorry to be boring, but just to add, if you have access then its worth checking your pipes and the lagging etc in any uninsulated parts of your home. I never have, but feel Ive now learnt my lesson... Luckily I was at home, but even just 30 mins of the leak produced masses of water and agro... Also, isolating the problem in this instance was made so much simpler because our plumber had installed those little screwdriver operated valves at suitable locations. Well worth doing if you're ever having work on pipes done.

thanks

 

[FamilyWiggs]

Likely to be a split pipe - relatively easy temporary "sleeve" fix kits available from the sheds (pick one up when you go and buy a ladder!)

Or possibly the connection between tank and pipe has been forced apart. Again relatively easy to fix. If the flow of leak stopped when you switched off the rising main, this is less likely to be your problem as the tank would have continued to empty after the supply was switched off. (unless it had already completely emptied )

Third option is something is interfering with your ballcock ( ) and the supply is simply overflowing the top of the tank (perhaps overflow is also blocked/frozen?)

If a metal tank, then it could possibly have frozen and split too.

Good luck - not the weather to be doing plumbing in a cold loft!!

 

[Flyfisher]

I'd agree with all that. The current weather is an obvious suspect, though it could just be wear and tear. We had a similar occuraence in a previous house that turned out to be nothing more than hot and cold water water pipes in contact with each other behind the hot water/immersion heater tank. Slight movement due to expansion/contraction over the years had worn a hole in one of the pipes. The resulting leak was small but went completely unnoticed until we noticed the plasterboard ceiing below the tank was bowing, by which time a lot of the damage had been done and most of the ceiling came down soon after.

That same house was also in a hard water area and we had infrequent problems with the cold water tank ball-valve sticking slightly open due to build-up of limescale. This was easily noticed by the outside overflow pipe dripping, but if that pipe had ever become blocked - perhaps iced-up as FW suggested - then that could have caused an internal overflow. My solution to the scaling problem was always to just rub away the limescale from around the ball-valve, which always seemed to work and, though not a permanent fix, would prevent the problem for another year or so.

None of which may be relevant but just goes to show that leaks can occur for many reasons but, unfortunately, the damage and disruption is always the same.

Good luck with finding the leak, wherever it is. The good news is that fixing such things is usually quite easy (though not if the tank has been damaged in some way), assuming access is not too much of a problem.

 

[Moo]

Early last week my local (3-storey, listed) Starbucks was flooded by a water leak somewhere in the roof. I arrived armed with my newspaper for my regular morning coffee to find the manager, assistant manager and a A.N.Other (a builder?) standing outside looking very forlorn. The ground floor was awash, water was still dripping, and a huge circular fitment that housed lighting, air-con and other electrical things was dangling from the ceiling. All this a couple of months after a quarter of a million pound refurbishment.
Of course, it will all be covered by insurance and Starbucks isn't short of a bob or two, but it has ruined my daily routine.

 

[worms]

I suppose there is an outside chance that the "burst" is simply an overflow blocked by ice, it is possible for a jammed or slightly defective ball-cock to go un-noticed until the overflow blocks. The sudden nature of the leak and the amount of water, however, might rule this out.

 

[robgil]

Have you noticed any water running out of any warning pipes outside lately? This is the first thing i would look for. I think a split pipe is the least likely but still possible.
If i were you i would get a plumber out. I have always thought water storage in a loft space is a stupid idea, its not easily accessed in an emergency and can cause thousands of pounds worth of damage if it goes wrong.
Make sure you have no insulating under your tanks and lots ontop of them.

 

[Penners]

I completely agree with everyone above. Anything copper or brass is more likely to be the culprit than a plastic water tank.

 

[Penners]

Early last week my local (3-storey, listed) Starbucks was flooded by a water leak somewhere in the roof.

Ah - I wondered why it was closed, when I passed the other day.

You'll just have to pop into my favourite coffee place in the Royal Arcade - on the corner of the little right-hand side-lane.

 

[Moo]

Unfortunately the clean-air police don't let people like me sit there any more, so I've been patronising the cornish pasty place - but not often, with these temperatures!

 

[c r]

Thank you people for your advice.

Well Ive a bit of very basic plumbing experience but never needed to do anything in a loft before...Ive been meaning to buy a loft ladder for ages so this has been the perfect excuse, its a great space up there...

The culprit in this case is a soldered connection just near to the join with a 2nd small loft tank (that feeds the boiler/heating system), that has come loose completely, hence the sudden rapid rainfall from my ceilings... Difficult to say now for sure, but its possible that the insulation on the pipe didn't quite reach to the end, where the connection has blown, but looking at the run of the pipe I think this section in any case does not look well supported, and was/is under too much strain.

Yep agree Robgil, if it was a more mysterious, complicated problem up there it would be sensible to call a plumber, but I would like to try and sort this in the evening myself just for my own convenience as much as anything else. I will follow your advice on insulation as its a bit minimal in my situation, especially above the tanks. So just one more question please whilst I'm here- how many mm of 15mm copper pipe will I need to fit a copper compression joint, is 10mm enough? I'll try and grab a decent plumbing book at the end of today to brush up on all this...

Thanks again

 

[Penners]

how many mm of 15mm copper pipe will I need to fit a copper compression joint, is 10mm enough?

It's tight, but I reckon 10mm should just about be enough. You can probably get away with having the olive only just pushed on to the end of the tube (but do make sure that the whole olive is pushed on, and try to get a wee bit of tube protruding if you can).

But why not resolder the joint? The only thing you need to remember is that you'll need to get the fittings properly dry before you attempt this - it's amazing how even a bit of wetness prevents the copper from getting hot enough to solder properly.

Once you've remade the joint, don't ignore the fact that it failed in the first place. Add plenty more insulation.

 

[c r]

Thanks Penners,

I don't have the kit at mo to solder the joint, and was also thinking as you say about getting the joint totally dry before soldering. As its very close to the plastic tank, more dismantling of joins would be necessary I think, even with a flameproof heat mat etc. I'm not claiming to be an expert at all- but if a copper compression joint would fit then I think (in theory...) its the simplest solution for me to do myself.

Thanks

 

[Flyfisher]

I agree that you should be OK with compression fittings as long as there is some pipe protruding from the end of the olives - 1/2mm should do.

However, I'd be wary of straining the pipework to get things to fit. If this is the case then it might be better to cut out a small length of pipe and replace it with a slightly longer length so that there is no stress anywhere.

If you do decide to do this then you could use a service valve to make the new joint, which could be useful if you ever need to isolate the tank in future. In fact, such a valve (or other compression coupler) will add about an inch to the pipe run anyway, which might be sufficient to take away any strain in the pipework and give you a bit more than 10mm to work with at the tank end, saving the need to buy any new pipe. If that makes sense.

 

[c r]

thanks for that aswell, FF. Well I'm gonna buy a fitting tonight and see if it looks feasible. Yep i like those islolating valves too, they saved me the other night! I didn't mention it before, but it unfortunately needs to be a 90 degree join in this case thats required, so I prob wont make further cuts to fit one of those valves. A shame.

 

[Penners]

Good advice from FF above about not straining your pipe run to make it fit, and about fitting a service valve.

Is it not practical to cut your tube back a distance from the problem joint, add a service valve followed by a new bit of tube (using the service valve as a straight connector), then remake the 90-degree run to the tank? That would seem to be a solution and an improvement.

 

[Moo]

Ive been meaning to buy a loft ladder for ages

When we'd had our last house extended I bought John a pair of His'nHers loft ladders for Christmas.
He was thrilled!

 

[Penners]

I bought John a pair of His'nHers loft ladders for Christmas.

You're such a romantic! But why one each - wouldn't he share?

 

[robgil]

Is the weak joint on the flow to the F+E tank or the feed to the central heating? I would think twice about using a compression joint , its a weak spot in the system and its in a very bad place to have a weak spot. You also have to find out why the solder joint failed, to fail like that isnt good news, the pipe may have frozen but there could also be strain on the pipework somewhere, perhaps caused by water hammer, a vibrating ball cock valve but also something may have moved and pulled the pipe apart. Putting a compression fitting in is bodging the effect and not really getting to the cause.

 

[Moo]

But why one each - wouldn't he share?

One for each loft, silly.

 

[Penners]

Putting a compression fitting in is bodging the effect and not really getting to the cause.

It's already been suggested that, if the cause was freezing, extra insulation is essential. But if the cause was water hammer, then I'm not sure that I agree with your opinion of compression joints. I should have thought that a compression joint would be more capable of coping with water hammer than a solder joint, in that it is inherently more flexible than the brittleness of solder.

But that's only an amateur opinion, based on a gut feeling. And I do agree that if water hammer has caused this problem, then its cause needs sorting out.