Talk to me about condensation

[HeyMacWey]

Since autumn has appeared overnight I woke up this morning to find condensation on all the windows.

How can I minimise it?

Central heating is not yet on. House is double glazed bar two windows and generally warm in the mornings.

Have a woodburner and the last few days have been putting it on about 2ish and then putting load of coal on at about 5pm so it simmers gently all evening and ensures that it's warm when dh gets in about 11ish.

Today I've kept the upstairs windows open a few cm to keep air flowing to see if that makes a difference.

Should I keep them open all night?

Clothes have been line dried and then finished off on an airer in the bathroom with the extractor on (door closed).

I've been squeegeeing the water off first thing and then noticed condensation building up on the unglazed windows when it gets dark.

Should I put the central heating on for an hour or would that not make a difference?

Any tips most welcome

We heat in short bursts all day. So we dont heat all day, but more than twice a day.

Does anyone know anything about anti-condensation paint? Worth using? I appreciate you have to sort the root of the problem too.

Or any other types of internal wall insulation to warm the room and lessen the problem?

We run a dehumidifier in the winter. If drying clothes inside, plonk the dehumid next to them. If it has been a cold night I put the dehumid in the corridor between DS and our bedrooms. Open windows on every sunny day.

anti-condensation paint is a layer 1 or 2mm thick. There are also insulating wall veneers of similar thickness.

Cavity wall insulation is about 60mm thick. Loft insulation is 100 to 270mm.

You can see that the paint is ridiculously thin and so has no significant benefit.

If the room ever needs replastering (or a bathroom needs retiling) you can get plasterboard or tile backer board which includes a slab of rigid insulating foam. It gives a worthwhile amount of insulation. Unless the room is very big, you would probably hack off the old plaster first.

We live in NZ where houses are generally described as shit. It doesn't get cold here apparently, so no need for central heating . Also mould is an issue as we have high humidity.

We've just had a ventilation system fitted. It has pump in the roof space and pumps the warm air from there down into the rest of the house through vents in your ceilings. It's made such a difference. Our house is drier and warmer and most days we get free heat from about 10am. Ours cost about 2k GBP and shouldn't cost much to run- probably 5GBP a month. Everything is more expensive here though so I'd expect them to be cheaper in Europe.

I wonder if these systems would good in the UK. Has anyone ever come across one?

I found a website for the UK:

www.admsystems.co.uk/index.php/products-9/heat-recovery-menu/heat-recovery-ventilation-system

We got an ebac dehumidifier - extracted lots initially. Now we leave it on economy auto setting and no more condensation.
Everything feels much warmer too.

I also use it on max if I dry clothes inside - speeds the drying up hugely too.

First frost of the year for us today.
We're in a rental and the lease had clauses about condensation - dehumidifier (brought from home in anticipation of this after reading lease) has switched itself on and condensation free!
Can see it on neighbours windows though!

What dehumidifier do people recommend? I'm about to replace the very mouldy roller blinds, and have noticed some spots of mould elsewhere too b

Bonzo. I did lots of research on this and we bought an ebac. It's neat and quote quiet. Was only earlier this year so model should be recent. Will check and post shortly.

I find that I get bad condensation on my bedroom window before we go to bed.
It's worse in the evening than it ever is in the morning.

Could it be coming from wet washing or bathroom?

Kakaka one of my friends has that sort of system in their house. It wasn't cheap but they got a grant to have it installed because of their child's disabilities. She said it has made a huge difference to the amount of damp and condensation.

We had a terrible condensation problem. The north facing bedroom wall was covered in black mould. clothes were going mouldy in the wardrobes. We stripped the wallpaper, cleaned inside wardrobes with mould killer from B & Q. Redecorated and then bought a dehumidifier. Which we run all day on a low setting. it does not use an awful lot of electricity and it does warm the room. We do not need heat on in that room. Now we have bought a smaller one for our north facing downstairs room. Problem solved. We do not have condensation on walls or windows now.

That's interesting mychildren. They are very popular here. Today it was 10C outside and sunny but when I got home it had warmed the house up to 20C!

I miss central heating though. And windows that keep the rain out.....

Kate - not sure on type of your dehumidifier but ours does several rooms from one spot.
Agree on it making the house warmer.

Something else I've just thought of - re drying washing in the house etc and tumble dryers ...
I have a condenser tumble dryer (doesn't vent outside) and when I was researching which one to get I found that someone (Which I think it was) had tested which ones were most efficient etc. Iirc they weighed the wet washing and then compared it to the dry washing plus water collected at the end - the main difference (they said) would be water that had 'escaped' as vapour into the atmosphere.
Some were much much worse for this than others - they tended to be the cheaper ones...but none of them were 100% efficient (or even close).
(I got a Bosch Exxcel -so that would have been a not too bad one).

Ours is a dessicant (sp) dehumidifier , yes it can be left in one room and if you leave the doors open it reduces condensation all over the house. The model we chose is light enough to carry and I hang washing to dry in the bathroom and put the dehumidifier in there. Washing is dry over night and no condensation caused anywhere else in the house. its great. ours is a Meaco DD8L, worth its weight in gold.

Could it be coming from wet washing or bathroom?

Nope, washing is dried in the tumble dryer and we only have showers etc in the mornings. It is a not facing bay window.

Water vapour is lighter than air and rises through the house, so it might be cooking steam or a faulty gas appliance.

How do you heat the house?

That should be north facing bay window.

Gas central heating with a sparkly new boiler fitted a week ago.
The double glazing is 17 years old though, I wonder if it is not past it's best.

I installed a ventilation system in our 3 bed semi last year and it's really helped with both condensation on windows and with black mood around the ceilings. They are called PIV units (Positive Input Ventilation ) and is basically a fan that sits in your loft with a vent in the ceiling. The fan circulates the air from your loft through the house, pushing the damp air out through the cracks, vents and windows in the house. You can get them with a heating element if you are worried about cold air from the loft making the house cold, but tbh we haven't bothered switching ours on. They cost about £250, you can get them on Amazon and if you're a competent DIYer are pretty easy to fit, although you need a qualified electrician to wire it in. We were quoted £1500 to fit it, but I did it myself in an afternoon preen. There's a fab website here that talks you through it along with some other tips. www.fixmyroof.co.uk/videos-and-guides/condensation-cure/piv-unit-system/

Other than that, I'd also recommend a good dehumidifier.

We just spent £££ on getting DS's bedroom sorted out because of condensation, mould and a window which would never quite shut. One wall faces W and gets the prevailing SW winds and rain and it was horrendously mouldy after a few years (ditto around the window). We just had the whole room stripped and replastered, with insulating foam plasterboard on that wall and a new window. It feels so much warmer in there already!

The mould appeared despite having a dehumidifier running daily upstairs, and if it's particularly bad for condensation on a given day, like today, I'll mop the windows with a sponge as well. We always push the curtains to the middle of the window panes too, so the edges get a chance to dry rather than stay damp due to the curtains being in front. (If that makes sense!)

you might also consider a wider curtain rail, so you can push the curtains sideways beyond the window. It will make the room brighter.

The new window may well have a trickle vent, which will give a small amount of constant ventilation. I am saddened by new windows with no vent.

Sadly no vent, and windows are literally wall to wall and already have a curtain rail that is as long as the room... cheap 1950s house construction!

PigletJohn - Hello!

I have some questions :)

I am north of Inverness, so currently at 2C and damp here today. In our bedrooms we have terrible condensation all day on the windows. Wet and you can't see through it. They get no sunlight during the day - back of the house.

We have roller blinds fitted and curtains, our radiators are under the windows. House is approx 15 years old and has shitty wooden double glazing.

Lots of baths and showers happen and I try to keep the bathroom doors shut and the extractors running (big vents that go out through the roof)

I have some companies coming out for quotes next week but we have a lot of windows 15 or so, but thinking of just replacing the bedrooms as a start.

Is it worth it? House is cold and holds no heat but we have done everything we can to insulate it.

Trickle vents are left open all the time for a bit of circulation but we never seem clear of condensation and the kids windows grow mould that I scrub every two weeks.

Any advice??? much appreciated.