The perpetual " Cornish" problem - damp and mold.

[sweetheart]

Some will understand this problem and others will not. You have to know abo ut wet and damp weather and condensation in old ( and over insulated mayb e?) houses.

So, winter is coming on and now I have to close the windows ( its colder) o r heat the rain and the wind outside. My condensation and mold problems are returning and they are spreading. What was a problem in the kitchen has n ow it the whole house. Its musty, stinking and black mold is growing in a lot of corners.

I have cleaned, painted and sorted all the maintenance problems. This is no t leaking roof, guttering or anything else. I have cut back trees and check ed under the floor. This is a condensation issue - beyond stopping breathin g. I am at a loss.

I have been told to put more insulation in, new windows double glazed and a ll manner of energy efficiency - and I did - problem made worse! Its stil l biggest in the kitchen ( where I have both a de humidifier and a heater n ow)

So, I seem to be down to two solutions. I either

(a) I have to turn up the heat ( most rooms are sitting at 20 degrees C - w ith the kitchen at around 15 C). I have even had one heater on all summer . ....

b) try for one of those ventilation things that go in the roof ( Nu air?) which promises to sort it out ( but, hey, promises, promises?)

Can anyone who has really had this problem and who has sorted it advise now ?

[Brian Gaff]

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

[Brian Reay]

I know someone who was plagued by condensation in a flat- we are talking furniture ruined etc. A dehumidifier didn't really help.

After some 'discussion', the landlord fitted one of those extractor fans which removes 'damp air', but uses it to warm incoming air. It was fitted in the bathroom.

Last I heard, it seemed to have fixed the problems.

[ARW]

Have you tried the stopping breathing method?

It was after all my suggestion.

[sweetheart]

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

[sweetheart]

about wet and damp weather and condensation in old ( and over insulated maybe?) houses.

r) or heat the rain and the wind outside. My condensation and mold problems are returning and they are spreading. What was a problem in the kitchen h as now it the whole house. Its musty, stinking and black mold is growing i n a lot of corners.

s not leaking roof, guttering or anything else. I have cut back trees and c hecked under the floor. This is a condensation issue - beyond stopping brea thing. I am at a loss.

Oh arent you sweet Adam - and so witty. Maybe you would like to take the st op breathing route yourself.

[Tim Lamb]

In message , sweetheart writes

Condensation leads to the mould. You have to warm up the surfaces or have less moist air or both.

Cooking, clothes drying, showering etc. all put moisture into the air in your home.

More ventilation and more heat will help but directly extracting moist air from the source could be a first move. Recovering up to 50% of the heat lost is worth exploring but ducting, disruption and cost a consideration.

[Graeme]

In message , sweetheart writes

Nothing helpful to offer, but I do, I promise, understand the problem. We are in Aberdeenshire, in a granite house built 1880-ish, with walls

30+ inches thick, single glazed Victorian sash windows, and the house is cold. Temp outside this morning was +0.4, and every window covered in condensation inside. By January, that condensation will be ice, in spite of the heating. Extractor fans in every bathroom, and no tumble dryer pushing out damp air. Three of us, breathing normally.

We don't have widespread damp problems, but there is mould in the two bathrooms we use regularly - one by two adults, the other by one 16 year old. We live with it.

[Andrew Mawson]

Have you tried running a dehumidifier? I have a largish commercial one that draws amazing amounts of water out of the air in a room (and hence long term the fabric of the room) so long as the room isn't cold. It also has quite a powerful fan, so the dry air circulates.

Andrew

[Harry Bloomfield]

sweetheart expressed precisely :

Sounds very like our semi, 40 years ago which was very damp and cold. I added DG all round, CWI, roof plus loft insulation and CH. I then added an automatic extract fan to the bathroom and a cooker hood which vented outside - I don't consider filter hoods to be any use at all.

I banned clothes drying anywhere except in the utility, then added fixed clothes lines, a dehumidifier (with a direct drain) and a small wall mounted fan in there. A dehumidifier is far more effective, if given the help of a small fan to move the moist air. In operation, that combination dries clothes easily over night, has much more capacity than a dryer and costs many times less to run. The utility is flat roofed, double brick wall, with no cavity, yet despite it being used as a drying room for many years, it has never suffered any mold appearing anywhere.

We do suffer a 6" square patch in the top outer corner of the bathroom (down wind). So a recent rule is to leave open the bathroom window for an hour after a bath to draw the moisture out.

It used to be an horribly cold house to try to live the winter in, huddled around gas fires and expensive to heat. It was originally built with a coal fired range in the kitchen, open fire in the living room, a second one in the main bedroom and masses of fixed air ventilation. Then it was converted to use gas cooking and gas fires.

Energy input now is very low and all of the house can be used even in the coldest weather. We fired the heating up earlier in the week for the first time since the summer. The stat is set at 19C and waste heat from appliances holds it close to that, so the boiler rarely needs to fire. It fired just once, last evening.

[Chris Hogg]

Oh, I understand your problem! We live a bit further south-west from you, on the Lizard. Black mould grows wherever there is poor air circulation: behind wardrobes, behind free-standing cupboards, in isolated corners, on cold north walls etc.

I'm sure you've heard these suggestions many times, but I'll repeat them in case there's something you've not come across. Cut down on all your sources of moisture within the house: don't use a free-standing or 'flueless' gas room heater, (they pump out masses of water vapour as part of the combustion products); don't dry your laundry in the house*, or if you use a tumble drier, make sure it exhausts to the outside; fit, and use, an extractor fan in the bathroom to clear the steam after someone's taken a bath or shower**; don't let cooking pots boil vigorously on the stove for extended periods when cooking vegetables, for example. They won't cook any faster, and cook perfectly adequately when simmered gently.

We find that spraying the black mould with HG mould spray is actually very effective and also long-lasting. It smells of bleach, so is obviously chlorine-based, but there must be something else in it because when we've used ordinary bleach in the past, the mould returns after not too long. With HG mould spray, I won't say it never returns, but it does take very much longer.

*We do use a dehumidifier quite a lot, mainly for drying the laundry in a spare room when there's not enough sun for it to dry it in the conservatory. **In the recent 'unFIT solar' thread there was mention of self-contained heat-exchangers that expelled warm moist air and drew in drier air (well, air at a lower humidity, although looking outside at the thick coastal fog and drizzle that's enveloping us here at the moment, I have my doubts about the actuality of that!). The incoming air gets warmed slightly by the outgoing air, so some heat is recovered, although not all of it. Something like this: or this Plenty more to look at here

[Bob Minchin]

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.

[sweetheart]

I have done everything you have suggested. I do not dry clothes indoors. I have a washing machine/tumble dryer outsikde in an old preparation room ( this used to be a market garden - not just a house). The prep room is detac hed from the house which means I get wet today going out to do my washing.

I have cut everything to a minimum - dishwasher runs only every other day. I dont boil the kettle unless absolutely necessary....... we have realy jus t got down to breathing and minimal living only but the problem persists.

I have put the heating on across the house to stop this mold spreading. Tha t does seem to work to an extent.

I have the dehumidifier running now as I am cooking ( I only cook once a we ek, the rest of the time I use a microwave or we have cold meals ( not exac tly good but I wanted to see what it took to sort the mold out.).

For what it is worth - and this could be nothing at all - I have found that the main wall for condensation is the back kitchen walls ( both external a nd north/north west facing). Today, as I cook, the tempreture in the kitche n is currently 20 degrees C and the back wall is dripping with condensation already. There is nothing at all on this wall. No appliances etc.

There are tiles on that back wall. I suspect its the tiles causing the prob lem but my OH says no. Certainly the condensation starts on the times and d rips downward. Where I have plain wall it isnt wet. However, the mold see ms to be spun around the room and starts from the back wall and works its w ay through the kitchen mainly across the ceiling and then unfortunately fr om there to the rest of the house ( a bungalow).

I do not strangely enough have any issues in the bathroom - yes, a bit of m old over the shower, but it is surprisingly free of mold compared to the ki tchen.

I am seriously contemplating the nu air system.

[ARW]

It's not me that is complaining about the damp for the sixth year on a row.

[Brian Gaff]

The daft thing is that I don't have any extractors and yet the bathing and drying of clothes inside causes little problem even when its cold. admittedly I only have two outside walls but they are not cavity walls and the windows thought double glazed are 1970 vintage. There has either to be some other source of water or maybe there are too many people all pumping iron in that house or something. Brian

[Fredxxx]

The trouble is that they consume a lot of power. Less of a problem if you have economy 7. 200W permanently running for 6 months is £100+

[Andy Burns]

Before retrofitting an MHVR system, I'd get an air-leakage report done, preferabky independent from the proposed supplier of the system, or you could still end up with an ineffective system, or lots of expensive work done to seal leaks.

[Fredxxx]

I was thinking of suggesting this route, you need extracts in normally the kitchen and bathroom with incoming vents in bedrooms and living room. Then a heat exchanger in the attic. Given cold outside air is less humid it's a good way for drying internal air and extracting damp air.

The noise from the forced circulation is a little intrusive but would have a timer to turn it off during sleep hours.

The other problem is decorating and making good afterwards. I think it would go some way to solving Sweethearts damp problems.

[ARW]

It's colder in winter?

The Daily Express will be happy to put that on their front page.

[sweetheart]

e. Its basically condensation.>

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

I think someone before me actually over insulated this house. Its 1950's an d its supposed to breathe, it was not built to be bubble wrapped and it do esnt breathe anymore - or at least not properly. All the surveyors and bui lders just laugh and tell me its " The Cornish problem" and I am lucky beca use 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.

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

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. Howe ver, I have lids on the pans. I have my oven door firmly shut. I have to cook and feed my family and myself.