Tank in loft - freezing risk

[Scott]

We have a cold water storage tank in the loft, which is not properly
lagged at the moment. My neighbour is convinced there is risk of
flooding of the water freezes then thaws. The tank is made of plastic
(PVC?) not lead. The lid is loose, leaving plenty of space for
expansion. To my mind, freezing would be an inconvenience but no risk
to the integrity of the tank.

However, she also mentioned the inlet and outlet pipes. Could they
freeze and present a risk? Anyone venture an opinion?

[tabb...@gmail.com]

Omit insulation underneath the tank, lag tank & pipes. You can always use scrap cloth if you've got nothing else.


NT

[alan_m]

Sods law and it will be a cold winter.

Around 25 years ago my neighbour disappeared on holiday for two weeks
over Christmas. His mother had the property next to him and also went on
the same holiday. Both houses had a lack of maintenance and I suspect no
loft or pipe insulation.

After week water started appearing from the eves on my neighbours
property. The outside stop cock was then turned off and on my neighbours
return industrial heaters were installed for a couple of weeks to dry
out the place. He sold the place a few months afterwards and the house
was completely renovated including new ceilings.

His mothers property had the same problem a few days later but this time
the water was going through the party wall of her neighbour property
(terraced housing). Unfortunately the outside stop cock for her
property was seized and the water continued to flow for a bit longer
until it could be turned off.

--
mailto: news {at} admac {dot] myzen {dot} co {dot} uk

[Dave Liquorice]

On Mon, 13 Nov 2017 09:56:03 -0800 (PST), tabb...@gmail.com wrote:

>> However, she also mentioned the inlet and outlet pipes. Could
they
> > freeze and present a risk? Anyone venture an opinion?

They could but assuming the house underneath is heated not very
likely unless you get several consecquative days around -10 C at
night and not rising above freezing during the day.

> Omit insulation underneath the tank, lag tank & pipes. You can always
> use scrap cloth if you've got nothing else.

Yep, doesn't take much to keep Jack Frost out. The biggest danger is
if the pipes pass through an area with a draught from outside coming
in.

--
Cheers
Dave.

[Davey]

Our neighbour went away for Christmas a few years ago, and one day, the
first-named on his emergency call list answered the 'phone, to hear the
sound of running water coming over the 'phone. The leak from the broken
pipe had shorted out the Emergency Call system, which had then called
the first number on its internal list. It took a lot of work to get the
house back into liveable condition again.

--
Davey.

[Michael Chare]

On 13/11/2017 17:45, Scott wrote:

It depends whereabouts in the country you are.

In central Kent there is a significant risk if the property is left
without the central heating on. Some time ago I did have a pipe freeze
fortunately it was a copper pipe and did not burst. These days I have a
frost stat in the attic. It is set to 1 or 2 deg and I have known it to
turn the boiler on even if we are living in the house with the central
heating on.

By the sea in Anglesey you might get away with it.


--
Michael Chare

[Michael Chare]

Did they not turn the water off before departing?

--
Michael Chare

[Adrian Caspersz]

Yup :(

In a cold snap the 80s, we had the water in an unlagged heating
expansion tank freeze, which proceeded to travel and freeze water in the
lagged pipes supplying it, moving apart a not very well made olive
compression joint and flooding the entire 3-bedroom house top to bottom
with 8 hours of unleashed mains water...

It was nightmare clean up, that one. All wallpaper removed and
dehumidifiers running 24/7 for a week ;-(

Lag the tank.

--
Adrian C

[Martin Brown]

On 13/11/2017 17:45, Scott wrote:

> We have a cold water storage tank in the loft, which is not properly
> lagged at the moment. My neighbour is convinced there is risk of
> flooding of the water freezes then thaws. The tank is made of plastic
> (PVC?) not lead. The lid is loose, leaving plenty of space for
> expansion. To my mind, freezing would be an inconvenience but no risk
> to the integrity of the tank.

It may not be the tank itself that fails but the copper pipe leading to
the valve that fills it. I saw what happens to an unheated upstairs flat
when a really cold winter causes a flood in 1985. It was impressive
since the rate of water fill was fast enough that the base of the outer
door failed eventually punching through other doors on the stairway.
There were cataracts down the stairs and ice everywhere outside.

> However, she also mentioned the inlet and outlet pipes. Could they
> freeze and present a risk? Anyone venture an opinion?

The pipes with water in are probably the most serious risk. If a 1cm
layer of ice forms in the tank that isn't fatal but in a water pipe the
pressure can rise alarmingly as the ice expands on freezing. It should
definitely be insulated. The overflow pipe shouldn't normally have water
in it and doesn't need insulation.

It is most likely a problem when it thaws out again after several days
at -10C or lower overnight penetrating frost. You would notice loss of
supply if you were living there but it it was empty all bets are off.

Polystyrene slab sheet will do a pretty good job of preventing it from
freezing. Recycled packaging would be better than nothing. As others
have said insulate the sides and top of the tank you want it to steal a
bit of warmth from the house underneath.

You may get away with it for a long time since winters these days are so
very mild. We had pelargoniums in flower outdoors last Christmas and
could have had fresh picked rhubarb crumble for pudding.

--
Regards,
Martin Brown