condensation on metal water tank dripping onto moulding ceiling

[george (dicegeorge)]

In the loft today i noticed loads of dampness on a metal water tank.

At first i suspected a leak, but now i guess it's condensation.

There used to be sawdust under it - was that to absorb the moisture until weather conditions changed and it evapourated again?

Theres black mould on the ceiling underneath

How can I improve things?

would a plastic tank be a lot better?

even then i guess there would be condensation which will drip onto the ceiling and create more black mould...

how is this solved?

or have i got some theory wrong?

[george]

[Phil L]

Highly likely someone has put the sawdust there to do just that....pathetic at best, but I have visions of it being someone old and frail who had no money.

Water doesn't condense on a warm surface, only a cold one and metal is one of the worst

slightly but not a lot.

wrap the tank in something, either a proper tank jacket, held on with string or failing that, just wrap some loft insulation around it....the moisture won't get through to condense

[Clot]

??? It does have insulation? Metal or plastic makes little difference to the amount of condensation but plastic does not corrode. The black mould on the ceiling will be due to the condensation dripping onto the plaster. There should be no insulation under the tank so that heat rises to aid the tank contents not to freeze. Does it have a cover?

Your comment about sawdust reminds me that that was the situation in my father's house. Hell, it might still be like that but fortunately I've not seen any mould below. The property is on the coast and therefore does not suffer the extremes of temperature that we might experience inland.

[Clot]

I'm not sure that you are right about this. I recall going into my parents and both grandparents lofts as a child and being aware that there was sawdust under the water tanks. All three houses were in the same area of the country and it could have been a local convention - read other post about location, though one house was approx. 1900, another 1920 and my folks built partly by my father 1950.

[Colin Wilson]

I was boarding our loft recently, and there was a load of sawdust under where the tank used to be (which had been removed long before I bought the house 20 years ago)

[Clot]

If I might be so rude as to enquire, when was the house built and what area of the country? As you might appreciate from my other posts, I've just become curious about this!

[george (dicegeorge)]

built 1880ish herefordshire..

there's sawdust under some of the floorboards too perhaps as insulation but it scares me cos its so flammable

[g]

[Clot]

Thanks for the reply. I appreciate the concern about flammability! Interesting in a historical sense. When was the tank installed? Herefordshire was not a county that had mains water early on. Though if close to Hereford, a supply was laid on about the turn of 1900s, I think. Spent some cold winter nights there in a portacabin in the 1970s when the sewage works was being rebuilt.

Hell, this takes me back.

[george (dicegeorge)]

there was a wheel or a ram in the stream which pumped water to the top of a water tower...

the condensing tank is a header tank for the hot water system I dont know if it's original or not...

[g]

under development!

[Andrew Gabriel]

It will -- you need insulation which is moisture sealed, such as encased in plastic wrapping.

[george (dicegeorge)]

so i could build a box out of kingspan around and on top of but not underneath and seal the joints with aluminium tape

[g]

[Andrew Gabriel]

Just checked in the BES catalogue as I have it within arm's reach, and proper tank jackets cost from £2.24 for an expansion tank, through to £8.08 for a 50 gallon header tank (+ VAT + delivery, etc) Hardly seems worth trying to make one.

[george (dicegeorge)]

so its worth getting the old metal tank out - it wont be a standard size, and has rust etc at the bottom which blocks pipes...

i got a plastic tank off freecycle some months ago..

[g]

[Colin Wilson]

Liverpool, built ~1936-1937 by the council