On 01/10/2017 12:10, sweetheart wrote:
On Sunday, October 1, 2017 at 11:37:06 AM UTC+1, Bob Minchin wrote:
sweetheart wrote:
On Sunday, October 1, 2017 at 9:06:57 AM UTC+1, Brian Gaff
wrote:
Small but significant leak in a pipe somewhere near a
radiator? I guess you need to run a de humidifier and see what
you end up with. If there are masses of water being removed
with few people in the house there has to be another source of
moisture somewhere. I mean you do need ventilation but not to
the extent of heating the outside! I suppose it is possible
that the surfaces concerned are much colder than the rest of
the place but unlikely I'd have thought.

Brian



There is absolutely nothing leaking. I have been through the
whole place. Its basically condensation.
--

OK No leaks then so where is the water coming from? I assume this
house is a relatively modern build standard with a damproof
membrane under the floor?

If there is a continuous DPM, then usually the answer boils down
to lifestyle. Sources are Breathing: already covered, unavoidable
but keep a small window open overnight in the bedroom to help.
Cooking: Use lids on all pans, microwave instead of boiling veg,
use extractor hood to outside from the start of cooking until 30
mins after. Laundry: never ever dry clothes in the house. Use of
high spin speed and a tumble drier is best or have a utility room
with a dehumidifier and forced air circulation. Bathing: showers
and baths create a lot of air born water vapour. A powerful
extractor when you are in the bathroom and open windows with
extractor still running for 30 minutes after leaving the bathroom.
Heating: long term heating will heat up the fabric of the house
and reduce condensation. short term heating just raises the air
temperature which enables it to hold more water which is dumped as
condensation on cooler walls.

If that lot does not improve things, and it really ought to, then
a mechanical heat recovery and ventilation system should be
considered.

The house is sound. I have had it checked, double checked and
maintenance has all been done.

I think someone before me actually over insulated this house. Its
1950's and its supposed to breathe, it was not built to be bubble
wrapped and it doesnt breathe anymore - or at least not properly.
All the surveyors and builders just laugh and tell me its " The
Cornish problem" and I am lucky because many houses are worse. But I
have a weak chest as a result of pneumonia a few years ago and the
mold is a big issue for me.

I have had it suggested I need to ventilate more. I have got
ventilators.

Exchanging warm moist air for external drier air with some sort of smart
heat exchanger might help a bit. Letting some more air in from outside
will help but getting rid of the wettest internal air will help more.

Every year I have to re pain the wall and ceiling and remove the
mold. I did it just a few weeks ago and its already coming back.

It shouldn't be that bad unless you have a lot of people in the house
all taking a shower every day and no air extraction in the bathroom.

I open windows but that really doesnt work. Its works in summer . It
works on a dry day. The hygrometer in the kitchen is currently
showing 70 ( 60 is maximum normal) . I am cooking and this does
increase the problem. However, I have lids on the pans. I have my
oven door firmly shut. I have to cook and feed my family and
myself.

Its the pans of boiling water that are the biggest source of water
vapour - do you have an extractor hood over the cooker hob?
Any other extraction in the kitchen?

A hermetically sealed house can end up with silly levels of humidity
inside if you make it completely draft proof. But I can't see that a
1950's house would be all that sensitive to being insulated. A Victorian
building with lime mortar and no damp course you have to be very careful
what you do since disturbing the moisture equilibrium in the brickwork
can cause serious trouble. Makintoshes Hill House is an example of what
can go wrong (he believed the claims of Portland cement render at the
time of building and it is now a nightmare to control humidity inside).

Bad problems once the impervious render ages and cracks water can get in
trapped against the brickwork but cannot get out except into the house.

--
Regards,
Martin Brown