Parents live in a small 1930's (or so) 1st floor flat with good double
glazing, central heating etc. In the bathroom they get a huge amount
of condensation on the cistern from water level downwards, particularly
after having a bath/shower in the room. They resort to having a tray
on the floor to catch the water as it drips off. It drives my mother
loopy. They have had both plastic and porcelain(?) cisterns with the
same problem. Any suggestions on what they can do to limit the
condensation? What's different about their house that should cause it?
- dampness/high humidity/extra cold water supply?

On Dec 5, 12:59 pm, "AA" wrote:
Parents live in a small 1930's (or so) 1st floor flat with good double
glazing, central heating etc. In the bathroom they get a huge amount
of condensation on the cistern from water level downwards, particularly
after having a bath/shower in the room. They resort to having a tray
on the floor to catch the water as it drips off. It drives my mother
loopy. They have had both plastic and porcelain(?) cisterns with the
same problem. Any suggestions on what they can do to limit the
condensation? What's different about their house that should cause it?
- dampness/high humidity/extra cold water supply?

Lack of ventilation when taking a shower/bath.

Insufficient heating in the bathroom.

MBQ

On 5 Dec 2006 04:59:30 -0800 someone who may be "AA"
wrote this:-

Parents live in a small 1930's (or so) 1st floor flat with good double
glazing, central heating etc. In the bathroom they get a huge amount
of condensation on the cistern from water level downwards, particularly
after having a bath/shower in the room. They resort to having a tray
on the floor to catch the water as it drips off. It drives my mother
loopy. They have had both plastic and porcelain(?) cisterns with the
same problem. Any suggestions on what they can do to limit the
condensation? What's different about their house that should cause it?
- dampness/high humidity/extra cold water supply?

1) They probably have the misfortune to have it fed from the mains.
That means in winter it is a little colder then water from the cold
tank would be and thus condensation is more likely.

2) They have inadequate heating/ventilation in the room.

3) It is possible to line the inside of the cistern with
polystyrene, glued to the sides. This reduces the condensation a
lot.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 5 Dec 2006 04:59:30 -0800, "AA" wrote:

Parents live in a small 1930's (or so) 1st floor flat with good double
glazing, central heating etc. In the bathroom they get a huge amount
of condensation on the cistern from water level downwards, particularly
after having a bath/shower in the room. They resort to having a tray
on the floor to catch the water as it drips off. It drives my mother
loopy. They have had both plastic and porcelain(?) cisterns with the
same problem. Any suggestions on what they can do to limit the
condensation? What's different about their house that should cause it?
- dampness/high humidity/extra cold water supply?

I found the main cause of this was the old fashioned overflow pipe.

There is a fairly large open pipe going from the cistern out of the
wall to the outside. Consequently the air in the top of the cistern is
at outside temperature and this spreads to the water in the cistern
and the casing.

Now I have a modern down the bog overflow, all condensation has
vanished, no matter how often we flush the toilet with freezing water
from the mains.

AA wrote:
Parents live in a small 1930's (or so) 1st floor flat with good double
glazing, central heating etc. In the bathroom they get a huge amount
of condensation on the cistern.

The good double glazing is probably a mixed blessing. The drafty old
windows that the place was probably built with would have provided for
a fair bit of ventilation. Also I'd guess it was heated by open fires
in the 1930s, which provide teriffic ventilation by drawing fresh air
into the rooms and sending stale air up the chimney. Furthermore I
would guess that the original inhabitants didn't go in much for nice
steamy showers, which put huge amounts of water vapour into the air.

All-in-all, this leads to an microclimate with lots of moisture and
nowhere much for it to go, especially in the bathroom. You really need
to get an extractor fan in there. If you've already got one get a
bigger one. I have a 150mm vent-axia one in my bathroom. If I turn it
off before I take a shower everything gets steamed up. With the fan on
the mirror stays perfectly clear. I've had the 100mm fans before in
other bathrooms. Unless the room is not much bigger than a cupboard I
don't find the smaller fans to be very effective.

"EricP" wrote in message
...
On 5 Dec 2006 04:59:30 -0800, "AA" wrote:

Parents live in a small 1930's (or so) 1st floor flat with good double
glazing, central heating etc. In the bathroom they get a huge amount
of condensation on the cistern from water level downwards, particularly
after having a bath/shower in the room. They resort to having a tray
on the floor to catch the water as it drips off. It drives my mother
loopy. They have had both plastic and porcelain(?) cisterns with the
same problem. Any suggestions on what they can do to limit the
condensation? What's different about their house that should cause it?
- dampness/high humidity/extra cold water supply?

I found the main cause of this was the old fashioned overflow pipe.

There is a fairly large open pipe going from the cistern out of the
wall to the outside. Consequently the air in the top of the cistern is
at outside temperature and this spreads to the water in the cistern
and the casing.

Now I have a modern down the bog overflow, all condensation has
vanished, no matter how often we flush the toilet with freezing water
from the mains.

A dip pipe, which takes the end of the overflow below the filled water
level, is also effective at stopping cold air coming up it.

Colin Bignell

Thanks for all the suggestions. The room is well heated but they open
the window a lot for ventilation especially during/after showering and
have an extractor fan too. The dip pipe for the overflow and
polystyrene lining are excellent ideas that i'll definitely try out.

On 6 Dec 2006 00:55:59 -0800 someone who may be "AA"
wrote this:-

The room is well heated but they open
the window a lot for ventilation especially during/after showering and
have an extractor fan too.

There is little point in running such a fan with the window open.
They should use one or the other.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

AA wrote:

Thanks for all the suggestions. The room is well heated but they open
the window a lot for ventilation especially during/after showering and
have an extractor fan too.

During heating season thats a waste of money & energy. A humidistatic
dehumidifier would work out cheaper.

NT