/ Home & Energy

Do you have damp in your home?

Damp house

The impact can range from an unsightly inconvenience to a health hazard. But can you get rid of damp problems by yourself?

There are households across the UK who are putting up with damp. Maybe you’re living in one of them. Some people are even sharing their living space with thriving communities of fungi as a result.

While I don’t share my home with a fungi farm, my flat does have a problem with the dank stuff. Living in the converted loft space of an old house, it’s no surprise really.

But I’ve managed to banish it from my home. And it would seem that identifying the type blighting your house is the key to dealing with it.

Damp proofing

We found in a survey of Which? members that condensation is the most common type, affecting one third of them. And this is what my home was suffering from, noticeably because it started in the bathroom.

Two thirds of Which? members with condensation problems dealt with it themselves. Most solved it by opening a few windows to improve ventilation – this is what I’ve done too. However, I also use a dehumidifier to soak up some of the excess water and avoid covering up the radiators in the room.

However, my friend’s flat had a rather menacing looking grey-black mould creeping across the hallway walls. And it wasn’t a condensation issue. It was penetrating damp, which can be spotted by the horizontal movement of the patches travelling up the walls.

We found that half of those suffering this type hired a builder to resolve the issue, but two ninths of them managed to deal with it themselves. The solutions ranged from fixing the roof (60%), getting cracks and leaks in gutters and downpipes repaired (33%) and fixing gaps in window frames and doors (15%).

But so-called rising damp seems the trickiest of them all to deal with. This variety usually reveals itself in damaged skirting boards and floorboards, crumbling or salt-stained plaster and peeling paint and wallpaper. There may also be a tide mark along the wall.

Solutions for this kind of damp may be a new damp-proof course or specialist attention injecting damp-proof cream into the walls. The toughest question, however, can be whether it is rising damp and if you do need specialist help to treat it.

Don’t ignore the damp

This just isn’t advisable; it’s likely to only worsen and it could end up being very expensive the more time goes on.

In the long run, identifying and dealing with it is important for your home, your pocket and your health.

Have you had damp in your home? How did you deal with it?

Have you tried treating a damp problem?

I tried but it didn't resolve the problem (39%, 409 Votes)

No I've not tried before (36%, 379 Votes)

Yes and it worked (25%, 262 Votes)

Total Voters: 1,050

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I have had an interest in damp both in my own houses, and in when managing blocks of flats. Not mentioned above is the bridging off the damp course, splash , leaking gutters and drainpipes. The danger is leaping to the conclusion it is rising damp which is actually one of the less common reasons.

Bridging by installation of insulation has already occurred and it seems some people do not realise that where you get driving rain this and insulation are a bad mix.

I have also had a friend die from double bronchial pneumonia and when clearing his third floor flat I discovered a well developed fungus along a wall in his study. It was hidden by the line of wall cabinets stood off from the wall. Despite the stand-off the fungus had bridged the gap and was active on the backboard

I believe that water from the guttering was penetrating the wall. However going from that to proof of death was going to be difficult following the cremation.

The Aspergillus Society is worth signing up for if you are generally curious. The WHO have done a large report on air quality in houses and the problems.


248 pages

A new one for the UK published last year highlights the importance of air exchange

The latter is much shorter and UK aimed. And very interesting. Particularly gratifying is they also are in favour of mechanical heat exchange


When we moved into our small 1830 cottage 24 years ago it did not have any ventilation in the kitchen as a result the windows steamed up and i saw it wasnt doing the wooden windows frames any good . I visited a trade electrical company and bought a 12″ Greenwood Airvac and an xpelair humidity detector electrical switch box which controlled it . My first thoughts were putting it in the window but its my one failing I am not good at cutting glass ,as the cooker was in a recess which must have housed an ancient cooker backing onto my gable end wall I made the brave decision to drill a passageway through 2 feet of solid sandstone .Pulling the panel away behind the cooker I was surprised to fine a square channel already there (great minds think alike ) somebody in the 50,s obviously had the same problem, anyway I got it all fitted up and surprisingly it worked first time cutting on/off depending on the humidity . I do not recommend a dehumidifier unless you are well off .IN Glasgow,s South-side tall flats were built in the 60,s when the slums were pulled down but it didn’t take long for the fungus to appear as ventilation wasnt part of the design . Years of complaints led to GDC installing humidifiers and many more years of complaints that the people living there being poor couldnt run them . This led to public outcry in nearly every local newspaper involving city councilors /MP,s etc till in the end the Council gave up and knocked the buildings down.


I have mentioned before I had a damp house. . . For the majority of my childhood I was brought up in a cold and damp house
There was no heat
There could be ice on the quilt from my breath in the morning
After we were married I got to move back to this house and boy what a load of problems
Better windows and more people made things a lot worse
I remember watching a snippet on some of the evening news bulletins about damp and mould
I have a bad chest and my youngest had the beginnings of such so we stepped straight into the car and came home with 2 dehumidifiers. . . Amcor. . . Wish I could get similar now without all the gubbins of buttons on modern ones
I could not believe the amounts of water we were catching everywhere and anywhere in the house. . . We were emptying them twice per day for the first 10 days or so then it began to ease off but the amounts of water was stunning
Prior to that I had tried like everyone to open windows and literally pour on the heat. . 24/7 in winter. . No heat and the walls were running with water
We’re talking around 2300L every 8 to 10 weeks in winter in a 1000 foot house as the stone part is
A terrible rubbish house pure and simple
We did not dry clothes in the house because the water has to go somewhere and we had more than enough to be doing with
I had learned or seen a lot of things when I was abroad and I used this knowledge to change our house
First thing to hit the skip was the poxy useless bathroom fan which could barely remove smell and so much so they all have to have a timer so they run after the light is switched off
I replaced it with a RUCK RVK type 4″ fan which fitted into the existing ducting. . .Wala, , No wet walls as in no absolutely no condensate outside of the shower and no condensate on the mirror. . . Great toys those fans

I later dry lined and insulated the old stone part of the house and that more or less made life easy and the heating and dehumidifier use could be cut down or out

Our house simply dripped of us and behind every headboard, ,wardrobe and so forth there was mould. . .My wife and I were never off the job with the various goodies sold to kill the stuff but it’s never killed to you remove the moisture
Remove the excess moisture and cool surfaces’s and there be no more mould

We also fitted 3 “through the wall” type MHRV units which are good but possibly a little enthusiastic for one room which they are listed as being for
I had tried to operate with the little window vents etc but once i had the knowledge I was not content to I had the problems licked
We had to use individual units as ducting in and existing stone house is near to impossible
I have now used whole house MHRV units and they are not much larger an air flow to the single units and I suspect having been inside them all now that the single unit utilises the same fan and labyrinth units. . .They certainly look very similar

I would not build without MHRV. . .No way
MHRV is absolutely constant ventilation whether its blowing a gale or absolutely still outside. . . .We need fresh air. . . Our houses are a little to well sealed today. . .And please dont tell us that yours is fine with opening windows etc unless you have either asthma/bronchitis or chest problems. . . Many people can live perfectly well in stale air but that doesnt mean its good for you. . . There are those who can sit in one room the entire evening and smoke until one can barely see and they dont seem to have a problem so its obvious everyone is not the same
Those with poor chests all to often seek fresh air

There is no absolutely no substitute for insulation. . Good insulation. . . Some retro insulation seems to have its problems but properly done insulation is the best investment one will ever make

We had no problems with rising damp but many told us our house needed chipped and re-plastered as the water was coming in through the old stone walls but I had seen this attempt made many times without success but it was a great expense to the owners

I have cousins who insist on drying clothes on radiators and will not run a dryer but they blame the builders for poor workmanship supposedly causing damp
The damp they have is around a few windows particularly on the north side of their houses and in my eyes the damp is condensate and is caused by a lack of ventilation made worse by this clothes drying procedure
A person emits quite a lot of moisture every day anyhow but add to that several litres of water with every wash and things just get worse

Having already posted and then read DTs and Duncan’s posts I seem a little vindicated in my notions
So I’m editing in a little bit here that I’d forgotten about
Duncan, , , Big fans, , great, , I have two 6″ powered louvre above the cooker directly out through the wall. . . No messy filters. . Get the steam out pronto

Damp is not good I feel


I must admit DeeKay I cannot see the sense in the cooker hoods I see in some houses that recirculate the steam back into the kitchen after passing it through a filter. They sure look impressive though with a great fat chimney sticking up but going nowhere!

Ironing is another great steam-producing activity and so few utility rooms have an extractor [or they are not switched on where fitted because they make a noise!]. I do quite a lot of ironing and like to do it in the garden when the weather is suitable so I can listen to the birds.


In an earlier Convo about dampness it was very obvious that condensation was far more common than structural problems.

Bathing, cooking and occupants breathing all contribute to moisture in the houses, and so does drying washing if that is done indoors. Gas cooking is worst because burning gas produces water, though an externally vented cooker hood helps to remove moisture, providing it is used. Unless there is adequate ventilation, the moisture can condense on cold surfaces such as windows and outside walls.

One of the problems of installing double-glazed windows is that they seal in the moisture, whereas the old wooden windows probably provided some ventilation even when closed. I keep windows locked slightly open except in a room with a chimney and keep pan lids on when cooking.


Wave if you ever got a taste for controlled ventilation you’d have all the windows closed tight to save the pennies
You are correct but maybe a little over stated on the gas cooking
The cooking its self produces much more moisture than gas flames do
For every 1kg of propane burned and its about the same for butane or for a similar amount of heat from natgas you’l get near enough 1.6kg of water into the room as a result of the combustion
1 kg of propane relates to 1.96 Litres odd and propane gives about 6.9kwh per Ltr of fuel
6.9kwh will cook an awful lot of food and there will be many litres of moisture boiled/cooked off 6.9kwh worth of cooking
Thats about 0.4L per kwh if my in head counting has worked
Each hob burner varies between 1 to 3kw rating when turned full on. . A big wok type burning will generally be 3.5kw turner full on. . .
I doubt if it makes much odds as most people have extractors above their cookers anyhow so any difference in the cooking fuel would be pulled out or should be
I avoid the “extractors” that dont extract. . Those carbon filter thingys that the salesmen have you believe make the water disappear and the filters block in no time anyhow so really their ornaments as you’ve got both the moisture and the smells still in the house

On the other hand the gas heaters with no flue (superser) we know them as are a disaster for making damp and should be avoided at all costs. . .Thats the ones with the bottle sitting inside the casing
It is even debated that it would be no more expensive to switch on an electric heater than to have to deal with the effects of those gas heaters given the silly price of those 11kg bottled gas anyhow

Our gas is bulk and a fraction of bottled price although it is still way too dear and there doesnt seem to be anyone to govern or help us so we just keep phoning and complaining

Proper flue’d heaters whether they be gas or oil are fine. . .

This may come as a surprise to some
Not everyone can have an electric cooker or better put not everyone has enough supply to have one
I have tested and monitored energy here for many years and I put my Dad in an 8kw electric shower as there was nothing else came close to his needs or rather his cabins needs but I kept it to 8kw because to fit any larger simply would be a waste and would not work
plus so I would not damage other things while its on I fitted CTs and relays to disable other circuits while the shower is on
An electric cooker can typically run from 10kw to over 14kw today so on top of our needs or greeds for many electrical appliances rural folk can often be stretching things a bit
A big 14kw cooker can pull around 60a and the biggest single phase fuse they’ll fit around here is 80a so there would be little left to play with. . . Before anyone tells me, , I also know plenty of folk have replaced them with 100a years ago but it should be 80a
I have had no trouble with the 80a because the more load we put on the lower the volts and that lowers the amperage of the resistive’s but there are still induction loads like fridges etc which can get to the point of not starting
My workshop has its own cable from the meter to try and at least eliminate the drop our side of the meter and transformer . .My compressor still starts but it has a timer and a solenoid to unload the pump until well after the motor has came off the start windings
Single phase dairy parlours usually have a few tricks to enable them to operate also


I agree with most of this, DK. I don’t have your experience living off-grid with gas cooking but that’s what I’ve been doing for most of my summer holidays since 1980. Then and at home using electric cooking I try to minimise the amount of water I put into the atmosphere. When friends visit and lend a hand with the cooking, it is obvious that they don’t think about this. It’s the only time I see steamed-up double-glazed kitchen windows. I’m moving home soon and will have a gas hob.

You are quite right about ventilation being energy hungry, but my energy bills are reasonable because I’ve good circulation and don’t heat the house as much as many do. I just lock a few small windows slightly open and works fine. Even in gales there is no noticeable draught.

Richard says:
12 March 2016

Having lived in a number of properties I can say from experience that the issues are simply put:
1. poor maintenance – leaks, gutter problems, poor flashing – or bridging cavity walls (poor build quality)
2. poor ventilation – blocked air bricks, tradesman removing roof ventilation when doing jobs etc.
3. lack of damp course in old buildings – not usual now
4. use of modern materials in old building that need to breathe e.g. use of cement strapping on stone buildings, use of gypsum plaster instead of lime plaster on stone walls, use of emulsion instead of breatheable alternatives, “dry walling” damp walls using foil backed boards – all of which seal the damp into walls which inevitably gets out somewhere OR builds up into an even bigger problem.
Obviously it is not always as simple as the above but I hope this helps and puts the problem into perspective for some people.

Martin36 says:
12 March 2016

Due to improved materials, using injected silicone cream in pre-drilled holes to establish a damp course in a wall, is easily feasible for a good DIY amateur. When I tried it it was very effective, though you can only reach that judgement after 12 months by which time the wall should have dried out.


I dont have rising damp in my 1830,s 2 foot thick sandstone block cottage . It does have underfloor ventilation BUT there is only 9 inches of space under the floorboards and the surface is covered with a tar like substance .

G lockwood says:
14 March 2016

I live in a 1960’s solid walled house. Condensation was a big problem, especially in the wardrobes. The solution I used was to internally insulate the outside walls, with either insulation backed plasterboard, or battens infilled with loft insulation and then plasterboarded. This all works, but is not cheap, even when doing it youself. You do of course have to deal with any electrical sockets and radiators, and you do need to extend any window sills.

Carole says:
14 March 2016

This is all very interesting but of no help to people who live in a rental property with an uncaring landlord who is only interested in receiving money & does not believe in doing even basic communal cleaning let alone maintenance.

Maybe it is time that Which started challenging the Govt. about the living conditions/costs of the seriously less able (mental health).


Carole-mental health is something close to my heart as I have seen many cases in hospitals I worked in . The government brought out – “”Care in the Community “” -ie- a money saver policy which to many does not work . This is down to what taxpayers are prepared to pay leaving the emotions out of it but its something that I cant be un-emotional about .Its basically foisting care for people onto many who are poor and struggle to look after their relative while at the same time they slyly remove any benefits that the carer gets but lash out money to greedy landlords . Its an unfair society but thats what the people voted for -share prices first-house prices second and to bad for the rest.


Duncan my emotions are not so easy to hide
My Dad 88 in May is for hospital tomorrow to investigate several things
We have been waiting on a morning/am carer call since Oct last year and now we need two carers three times per day. . .. Not a cat in hells chance
The social ask me direct in the eye that if I could not care for him they could get him into a nursing home. . .Of course they can that’s Big Business getting the money and they’ll need a top up which I have not got.
I am not a fit man and now my wife is off work to try and see this through as she said I could not take any more. . .Neither of us can get carers allowance. .
What happened to the idea of home care
The Gov spouted about care at home and support at home but its nowhere to be seen
I am told that the carers are now managed by “Brokerages” and I cannot help but think that that is just another method for BB to use up any money before it gets to us the ones who have paid all these years
My father was NEVER unemployed and was on the insurance once when he got his appendix removed. . Yes just once
What a load of absolute liars and cheats our politicians
Now more cuts. . . Why not come here and cut a few bits of me while your at it
Mr Ozzy and Cameron the pearly gates will never open for you lot you self righteous, self centred little men. . . You dont deserve the good place. . . Cameron speaking about a Christian UK. . . Christian my foot. . More political “sin” spin
I am not a religious type person but I do know that the very basis of Christianity is to help the needy, the young and the old. . . Suffer the little children. . . Honour thy Father etc
Anyone with an IQ of 5 knows that one but what do these guys do? They give better tax breaks to the wealthy


You get a thumbs up and an applaud of hands from me Dee for that sincere post and I can feel your emotion.

julz says:
13 April 2016

we moved into a 1600 3 bed cottage, and I’ve notice mould patches in most rooms, I have the Windows on breather, and the morgoity of the Windows are double glazed, all chimneys apart from one have been boarded inside the chimney, I believe the walls are extremely thick, and I doubt they have any kind of insulation, do I need to have some kind of injections put in?


Been there got the T-shirt
Are you drying clothes inside the house .. . .Does not do well with stone walls
The double glazing makes the problem worse
I had to line ours out and then no more damp

Prior to that we ran two dehumidifiers for about 8 months of the year otherwise we had mould behind everything. .. We are in NI and it’s cold a bit anyhow

Its all to do with the differential between the walls and the warm moist air inside

You’ll also need a good extractor in shower/bath. . . 100mm RVK ruck fan is good start to stop damp migrating from there to the rest of the house

Nothing beats insulation


Julz-to save a long reply and inputting the various methods of repair to narrow this down and provide some help for you ,head to— wealdon.gov.uk/Wealdon/Residents/Housing_Health_and_Advice/Housing/Private_Hc . Come back for advice after reading it.


I thought that this might be an interesting update for this convo. We’ve taken a look at water extraction claims made by leading dehumidifier brands and found that many are somewhat misleading.

Refrigerant dehumidifiers are the most common type in the UK, but we found that many base their claims on how much water is removed over 24 hours at 30ᵒC and 80% relative humidity – conditions you’re more likely to find in a tropical rainforest than your home 😎

Our full news story is here: http://www.which.co.uk/news/2016/04/dehumidifier-claims-are-misleading-and-unrealistic-which-finds-439665

Jarek says:
26 April 2016

Hello. Damp can have many reasons but if you have salt contamination or rising damp , reverse osmosis or electroosmosis is just the best. It change polarity and water can’t break it.

Magi says:
2 May 2016

Jarek, could you tell us sucessfull cases of rising damp treated with electroosmosis? It is the option I am checking at the moment for my house, but I don´t find any clear position about if it really works or not…..

Monica Bruce says:
18 February 2017

I have condensation damp in my loft. Has anyone got experience of closed cell foam insulation and can it help?


Monica-condensation (leading to mold eventually) is normally the result of inadequate ventilation unlike water ingress due to gutters /roof damage /etc . Many councils throughout the UK have tried to cure this and in the case of 60,s style flats in Glasgow everything was tried including free humidifiers but as the residents were poor they did not use them and when some did they quickly filled up or were inadequate due to the terrible situation after years of front page complaints a solution was found —- the building was demolished and the residents rehoused. Closed cell insulation provides Thermal insulation reducing air/water vapor infiltration through the building element I personally don’t see how that will help if water vapor is INTERNALLY produced it will only exacerbate it. Having said that IF the water vapor is entering externally and NOT internally then there might be a point to it but this job has pitfalls it must be done expertly and EVERY slight opening closed , reading the complaints only go for a firm who GUARANTEES it for a year or two and NO “cowboys “.


Lack of ventilation is possibly the problem. You can fit ventilating tiles at intervals, if you have a tiled roof. check the ventilation in the eaves is not obstructed – there should, in older construction, be a gap between the soffit board and the fascia or wall or, later, vents fitted into the soffit. these can get blocked by insulation.


Vivica Cornelly is a professional blogger and posted this on youtube – I have COPD -I am 54 years old and I was told I had COPD 7 years ago -problem ?? the youtube video is dated – October -2012 — this is now -2017 – same post -same info , if you dontvget it then she would have had it FIVE years MORE in -2017 – penny dropped ? She advertises “smart inhalers”on COPD Forum also on -Ask US -brain-blogger.com – same person same post still the SAME age etc in October -2015 -smoking tealeaves- askus – vivica Cornelly-same post -nutrition facts .org -never ages etc website after website same post . I have no problem with people posting on different websites BUT – to LIE about the AGE of the post as if it applied to the present ? Look into this Which !


Duncan – The post is clearly promotional and against the rules. Simply click ‘Report’ to make the moderators aware.


I’ve also reported it as SPAM, so if three of us do the post should disappear.

Edit: And it’s gone.