Damp and mouldy house

stuart45

You might find the CWI is wet. 

jacko220

Condensation in buildings - Designing Buildings

Suggest you look at this for Condensation problems, triple glazed windows 2.0 W/m^2/Deg C. 50s cavity wall insulated about 1.6 W/m^2/Deg C.

Check Driving Rain Index for site and if the insulation was BBA approved.

If you have any questions please ask. I lectured in Construction Science for nearly 40 years.

Basically cold air cannot hold as much moisture as warm air, look at the psychrometric chart.

I basic difference from last year new baby, bathing every night produces a lot of moisture, drying nappies? . baby in small room/bedroom breathing. Look at BS5250 for advice.

Hope this helps.

Effician

Loza2016 said:

If you don’t have trickle vents can open the windows slightly at night on latch. Still secure but will give a bit of ventilation. 

Trickle vents made our condensation considerably worse, not all ventilation in winter is good.

housebuyer143

Have you tried running a dehumidifier and seeing if that solves it? When we introduced a baby into our house it threw everything out and we had terrible mould and condensation..
Used a dehumidifier a few hours a day and it completely solved the issue.

FreeBear

jacko220 said:

Condensation in buildings - Designing Buildings

Suggest you look at this for Condensation problems, triple glazed windows 2.0 W/m^2/Deg C.

Minimum thermal requirements for windows is currently 1.4W/m²k (June 2022). It had been 1.6W/m²k for several years before that. Triple glazed windows should be getting close to 1.0W/m²k.

But that is all academic as far as the OP is concerned as it doesn't help when the walls are cold enough for condensation to form.

Merlin139

We have been opening all the windows in the house for 5 to 10 minutes each morning to blow out all the stale air. Then we put the heating on. We have trickle vents on all windows open. Condensation has ceased to be a problem since we started doing this a couple of weeks ago.

We only have heating on for around an hour in morning then from 17:00 to 21:00 in evening. Most days its just me at home during the day. I know how to keep active and warm so don't require heating during the day. 

Murraymoocow

Thanks for all the replies. I spent yesterday afternoon moving a large wardrobe that was in front of part of the worst wall. Behind it the back of the wardrobe was black with mould and the wall was green and damp most of the way up. 

It looks like the roofers cut the felt short when installing so there is a gap around the bottom of the roof. Not sure how much of an impact this will have had but someone is coming this weekend to sort it somehow.

Will be looking into the roof insulation aspect further as there have been so many bodges so far. 

I know the obvious answer is condensation/ living habits but this just seems so much worse than anywhere I've lived before. I'm going to have a chat with the neighbours who asked us if we had damp when we first moved in. Of course we said no but that was in the summer of 2021 when the temp was in the 30°s. I suspect the house might have a history.

Thank you for all the help I really appreciate it.

twopenny

Nobodys yet mentioned the wall insulation.

I had a 1920's house that warmed with the sun due to aspect. Everyone was getting cavity insulation free form the government so I grabbed the oportunity as they said it was so good right?

For me yes, if the heating was on it got and stayed warmer. But I had to put the heating on more because any outside heat didn't get through the walls. This was the bead stuff. I had no choice and knew no better but I did think it strange that no difference was made for old or newer houses.

A friend bought a beautiful flat conversion of a 18th century building and had condensation running down her double glazed door, windows and problems with damp.

It would be interesting to know from the neighbours (if they know) if the problem started with the insulation of the walls or double glazing.

Another thought is has the house been rendered and painted with modern paint?

Any extensions?

Also being of that age have you investigated 'cold bridging'. Used in 50s I believe, from Scandaniva. I found it hard to find a simple description so maybe worth a google.

Scrimps

I know a couple of people who have had positive input ventilation (PIV) installed and say it has worked really really well. "First thing we noticed was the doors fitting in their frames, before they were too swollen from the damp" was the feedback i was given. But don't bother with the heating part because that is expensive to run.

We haven't done it because we have asbestos ceilings we can't cut into so just use a dehumidifier to pretty good effect.

macman

You really need to check the loft insulation as a priority. If that's not present it will massively increase heat loss. Can you not just stick your head into the loft to check?
It's also one issue that can be resolved in a day, if necessary.