Would dry-lining help reduce condensation

[Redeye]

The downstairs walls in my house suffer from several areas of condensation which I'd like to try and do something about while we're re-doing the kitchen and dining room. For some reason the worst of the condensation is on the internal brick walls, not the external stone ones, which seems a little strange to me but that's the way it is. I'm pretty sure it's condensation rather than rising damp - it's much worse in the summer than the winter (when we've got the heating on, lower absolute humidity etc). We've improved ventilation in both rooms although it's not made a great deal of difference really.

The bottom 3 foot of plaster right through the downstairs has been re-done with gypsum plaster at some point (not entirely sure why but could be damp related) and the plaster on these walls is a real mess (looks like a bad DIY job). We'd like to paint these rooms instead of the orange wallpaper we've just removed from them(!).

My question is, would dry-lining help alleviate the problem? Common sense says yes, but I think there are greater experts than me on here who probably understand these matters better and some advice would be greatly appreciated.

 

[biffvernon]

Yes, dry lining might well help. We have a similar problem. Lime plaster survives getting damp better than gypsum so it might be worth trying that first. That's what we did and it ok enough to live with though not perfect.

 

[Roger H]

Do you reckon its on the internal wall in the summer as that's the 'thermal mass' and is taking a longer time to heat up versus the external walls?

In the winter it is perhaps less prone to condensation because the internal brickwork is accumulating heat while the external walls are beset by outdoor cold. Seems a shame to dryline if the wall looks nice though.

 

[NT]

If it is condensation, dry lniing will lower the temp of the wall, since it will no longer be in contact with room air. Lower temp means condensation will worsen, plus evaporation be prevented, so drylining would make the wall wetter, plus disguise it for a while.

However condensation is unusual on internal walls, salt contamination might be the culprit. Lime plastering has been used as a slow means to treat this, the salts end up in the plaster due to evaporation, and the lime comes away in time taking the salts with it. Very slow process though.


NT

 

[Redeye]

Roger - Yes, you may well be right. I'd not thought of it like that, but the thermal mass of the walls may well have an effect.

NT - I see your point about lowering the temperature of the wall, but would there actually be enough circulation behind a dry lining to allow condensation?

Something interesting that I've noticed in our house is that if I increase the ventilation in Summer then the condensation gets worse. I've put this down to a higher absolute humidity with warm air which comes into contact with the cold walls. Because it takes so long for the walls to warm up (the inside/outside temperature lag in this house seems to be about a week) it rarely stays significantly warm for long enough in the Summer for the walls to warm up.

I think I'll just have to try something and see what happens. I guess the worst case scenario is that we have to strip all the plaster off and start again...

 

[NT]

NT - I see your point about lowering the temperature of the wall, but would there actually be enough circulation behind a dry lining to allow condensation?

There would be more or less none thus very little condensation. But equally little evaporation - in fact less, since temp is lower. So yes it would be a very slow process, but in time it just makes it worse.

I think I'll just have to try something and see what happens. I guess the worst case scenario is that we have to strip all the plaster off and start again...

Guessing is a very wasteful approach, and the cause of much damage to PPs..

How about the simple solution, a dehumiifier. Whether it turns out to be your chosen final permanent treatment or not, it will definitely stop the problem, costs much less than other approaches, acts almost instantly, doesnt do any damage (caveat to be noted), and some of the cost can be recouped later if wanted.

http://www.wiki.diyfaq.org.uk/index.php?title=Dehumidifiers

caveat: always use a humidistatic one, and dont set RH very low.


NT

 

[MdB]

I've recently removed dry lining from a damp wall where the dry lining had been in place for 10 years or so I think. Might have been double that. As the damp in the wall had not been sorted out, the inside of the cavity had a large amount of mould on the old wall surface as you might guess. The stud work had a strip of DPC plastic behind and was tanalised and didn't show any signs of rot. The plasterboard on top though had failed along the bottom edge where the wall was the wettest. In one section a hole in the plasterboard had been filled with cardboard and then wallpapered over... The metal boxes for the sockets had also badly rusted.

One section of the dry lining though was fine. This part held the ventilation duct for the gas fire which allowed air to circulate behind the plaster board. If you do end up adding dry lining then from this experience I would suggest adding some ventilation grills to allow air to move behind the panels.