Insulating Under Water Tank

Tidyweb

I have a fairly large water tank in the attic - 8ftx3ft.

I have been told you dont insulate under the water tank.

Is this correct?

It seems like a large are to have uninsulated. Should you just leave a strip beneath in uninsulated.

Or is that rubbish - the tank would harly freeze in irish weather.

Kingchip

Don't insulate under the tank. Insulate the outside of the tank. The heat rising from the room under the tank should stop it freezing in extreme weather like a year ago

sligo camper

i agree with king - never under, always round

remember the winter of 201o!:(

Neilw

Yes underneath should be left uninsulated, wrap insulation around the tank down to floor level so as to make a seal to attic floor level. This traps the heat that has risen from inside the house and should stop the tank freezing.

I've mine wrapped in a jacket then wrapped in 6" insulation down to the floor, lid is also insulated and covered.

Tidyweb

Thanks for the feedback.

Regarding wrapping your tank in insulatation.

This would be more to keep cold out than trap heat in the house, as I assume you would never heat the water in the tank to the point where insulation on the tank will keep heat in the house.

Would it make sense to run insulation a little under the tank and leave a small area uninsualltaed, or leave all under the tank uninsulated

BryanF

Tidyweb wrote: »

This would be more to keep cold out than trap heat in the house, as I assume you would never heat the water in the tank to the point where insulation on the tank will keep heat in the house.

:D

the idea is - keep the tank within the insulated envolpe, so it doesn't freeze;)so take the advice of others above and insulate sides and above the tank and all pipework, but NOT underneath it;) imo use a timber composite,(Gutex or similar) or PIR PUR (kingspan or similar) and not loose mineral wool for this area.

Tidyweb

Ahh

An insulation envelope, now I get ya.

edanto

You're basically using the insulation to make a skin dividing the warm side of your house from the cold side.

You want to make sure that the water tank (and all pipes - e.g. shower feed) are firmly on the warm side of that divide. So the insulation goes over and around the tank.

Leaving any pipes uninsulated on the cold side of the divide exposes them to a freezing risk. Many unlucky people were caught out by that recently. It's expensive.

BryanF

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Joey the lips

actually if the tank is so far off the ceiling your ment to insulate it underneath as well. But i prefere to put polystyrene from down the sides of the tank till it meets the ceiling.

You should put a thin sheet of wood between the tank and the ceiling to absorb any condensation from the tank. Otherwise the ceiling will.

Neilw

On a side note. My attic floor is foil backed plaster board of some sort.
Will heat from the living space travel through this to the underside of the tank?

My tank is wrapped with an insulated tank blanket and then mineral wool around that to attic floor level. I like the idea of using knigspan or similar as BryanF suggested, might be a little project for me