Why is my house so damp when it never used to be this bad?

[CormorantStrikesBack]

I5s an old Victorian house. I know that damp is generally down a lack of heating and ventilation.

so I have the heating at 19degrees. I admit I’m not great at this time of year about having windows open but I manage ten minutes in the morning in our bedroom before going to work, longer if I’m wfh. But I’ve never been great with the windows so no different to normal.

The house is noticeably damper this year than previously. There are damp patches on all external walls, condensation on the walls. We are getting mould.

i am wiping the walls every day. We use a window vac on the windows every morning. I have a 12ltr Meaco dehumidifier running constantly. So it’s been going in my bedroom with the door shut most of the day, I started it at 8am, went up at 6pm and it was full so had stopped. Started it again and the reading is still 80%. Room feels damp. It never used to be this bad.

i move the dehumidifier downstairs overnight. I probably could do with one in every room but can’t afford the electricity! I’ve ordered some of those non plug in ones, not sure how useful they are.

do I need to get anything structural checked with the house? I asked dh and he just said well it’s cold outside so we’ll have more condensation. But I swear a few years ago it wasn’t like this even when cold.

Do I turn the heating up to 20?

Get the building checked. My dehumidifier right next to soaking wet laundry is never more than 75 and quickly dries the air out. If it’s getting 12 litres a day from one room that’s not from normal day to day use. Have you checked gutterings?

People who are saying it was all the summer rain, where do you mean the water is? Do you mean it got into the ground then is sitting under the house and coming up through the floorboards? Surely it can't be in the walls?

I think it is in the walls. Literally when there was the big storm a few weeks ago my walls inside got noticeably damper, big damp patches appeared. Just on one side of the house, which was the side the wind was making the rain drive into the house. Dh reckons the bricks are saturated. My neighbour mentioned about the sealant stuff a pp mentioned which you can paint on the brick. Dh reckons we need to wait to use it till spring, that there’s no point putting it in wet brick.

im going to get someone to check the gutters first. Then if they don’t find anything get a proper surveyor round. Anyone any idea of price for a surveyor?

we just have one bathroom, it has an extraction fan which comes on when the light is on. We make sure we leave it running after a shower.

i was reading about the positive pressure ventilation units which seem the same principle but simpler to fit than the mvhr ones.

When I got my Meaco 12L dehumidifier I read up a lot on how to use it most effectively.

Main points:
🙂Put it somewhere central in the house (I’m in a 2-up-3-down and have it on upstairs landing)
🙂Keep all doors open
🙂Keep windows shut (so it doesn’t try to dry outside!)
🙂Let it run 24/7 with no limit for first couple of weeks (took me 3 weeks for it to go from 87% to 63%)
🙂Set it to between 55-65% once it has hit a regular target (have got mine set to 65%, which it generally sticks to, goes up to 67% by morning but settles down quickly)
🙂Leave it to do its Thing! (it turns on and off throughout the day and needs emptying once every couple of days or so now whereas at first it was twice a day)

Following these points means the house has never been warmer or drier. Haven’t got the heating on regularly, perhaps once every couple of days after school for a couple of hours if it’s chilly.

I’d leave your windows open and try not heating for a bit. Shut them when you have the heating on.

ive read that fires and stoves are a better way to dry out old houses as they pull the air through and up the chimney. Have you got a working chimney?

It can be in the walls, yes. Some rain does soak into brickwork/stonework, and everything inside the hoise (plaster, furniture, inner leaf of cavity walls) will be carrying more moisture than usual because it jas been so wet and mild. To make matters worse, once a solid stone/masonry wall gets damp, it actually conducts more heat and so is even colder and more prone to condensation.

I don't think 19 degrees is unreasonable at all, but it does need to be combined with ventilation. Good idea to run the dehumidifier when laundry is drying too. It's not cheap, but then neither is having to redecorate and replace stuff 🙁🙁
On the upside this cold weather is making the air pretty dry so heating and ventilating ought to work well at the moment. Its also a good idea to move everything (furniture etc) a little bit away from outside walls so the warm air can get behind, as that is a classic place for damp and mould otherwise.

24 🤣
Out house has never been more than 20 and normal around 17. We have never had damp (house well over 100 years old) with 6 of us in it.

Check all your gutters and downpipes are running clear, you shouldn’t be able to see any water coming out of them or onto the house.

what is the house constructed from? As a PP said for a stone cottage, we had a similar silicone solution painted on our stonework and it stopped the damp. If it’s a painted house, does it need redoing? Do you have specific rooms or areas where the damp is recurring?

Damp is basically water in the wrong place. It has loads of different causes.
• blocked gutters and downpipes
•leak on the water supply pipe coming into the house
•collapsed drains.
•leaky roof
•rain getting down a chimney
•boarded up chimney not fitted with vents
•leak on heating system
•damp course bridged by soil or tarmac
•high water table

House is brick.
no cavity wall
damp is worse on the back and one side, ok at the front.

we have a stove in the living room which is used a lot. That room still has damp. Noticed today the curtains are ruined.

a few years ago we had the front of our house, which gets prevailing weather, painted with a silicone solution that waterproofed it. We needed to do it again this year. Ours is an old, stone cottage.
aghhh! Nooo!
stone and brick needs to breathe. Cement and silicone and modern plastic paints ( even ‘microporous’ )keep damp in.
our old atone house was damp, and the windows rotting, when we scraped off the resin, or whatever had been painted on, the sandstone was soaking wet. It dried out though and the house is a lot less damp.
readthis.. https://www.heritage-house.org/damp-and-condensation/managing-damp-in-old-buildings.html
someone had also paid to have dampproof stuff injected about a foot off the ground, the idea being that it seeps inside the stone creating a layer of waterproofing so the damp can’t rise. Err, no. When we replaced some of the stone, it hadn’t spread out at all, doh.
and do not get in a damp chap. He’ll scare you with science and charge a fortune. Look for cement - often modern cement in the outside brick wall leads to damp appearing on the inside.
and yes, open windows 😳

Proper RICS building survey will be £1200 - £1500.

Do it asap and don’t paint any crap on the external bricks or do anything else until you have his report.

we have had a much more difficult time with damp this year than previous. The constant rain has multiple impacts, such as limiting ability to open windows and air out the house, as well as increasing likelihood of guttering becoming overwhelmed and overflowing into the building.

we try to open up the house as much as possible on dry days, even if cold, as that has biggest impact. Double check guttering and the roof - storms have shifted tiles, blocked gutters have overflowed and aging chimneys have been a point of water ingress for us. Dehumidifiers in problem areas, as well as running the wood burner have also helped.

And @Drwhattf is right - make sure damp can escape. Most damp actually comes from inside (cooking, bathing, breathing) than wet penetrating from outside. That is why opening windows is so effective.

we removed a meter of cement render around a corner of our stone house and damp disappeared from those rooms within 6 months.

I was going to say similar to above that I wonder if your house has had ill-advised damp-proofing in the past and that has sealed damp in and it can’t get out.

Obviously the damp patches that arrived after rain are coming from outside, but condensation generally comes from inside.

You need a survey.

80% is extremely high, you say it is worse than usual, curtains are getting ruined and you have visible damp patches.

Survey will be a couple of hundred quid, get a recommendation from someone you think is sensible.

I’m in a Victorian house and have got much more noticeable damp this year. Interesting to read about the wet summer and how it may have affected everything. We have problems with one wall/ side of the house in particular, and the sun doesn’t hit that part, so maybe it is saturated.

It can be on the walls. Brick soaks up a lot of water. We have about a 4' void under our floorboards under which it's just earth. Even with the best damp course, that would still moisten the air.

Additional assaults our 90 year old house has had this year have included builders next door not replacing guttering properly and missing a couple of 'clean heat exchanger" warnings on our dryer which caused a heck of a lot of condensation.

We also have this behind our wardrobe! Not wet to touch and not ‘fluffy’ just a huge amount of staining and spots all over. Is this damp too?

Victorian houses didn't have the same type of foundations as newer properties, a few bricks, shallow foundations, or pretty much built on the ground which is often the cause of damp.

You might want to look into the foundations. There is a fair amount of information on Victorian houses online, I first found out about this when someone I know was working on a house that had no substantial foundations.

@clopper yes

When I bought my house. After a full refurb down to the bone

I had the heating on at 32 for 2 weeks straight Before moving in.

That is mould I think.