Re: Condensation on solid wall

[sean.mcnicholas]

Hi Can anyone advise please? Live in a victorian semi-detached property built approx 1890. Have a problem with condensation on the internal party wall, the walls are of solid construction i.e. non cavity. Had a damp survey undertaken which resulted in drilling the wall and analysing the contents. The surveyor informed that the brick was dry and the problem was due to condensation. The wall has been previously skimmed with a DPC injection. The problem is getting worse with damp patches on the skimmed plaster, it gets worse when it is raining. The plaster is cracked and has started to flake and crumble leaving a white powder on the grey concrete underneath which look like deposits of salts. A chrome electrical socket has also started eroding and crumbling away. Unsure of what to do next? Should I remove all the plaster/ material off the wall and place in a drywall system? Hope someone can help. Cheers Sean

[dg]

Its unusual to get condensation on a party wall, as the heat from next door should keep it warmer than the external walls. You say that it gets worse when raining, but the party wall is an internal wall - unless you have a roof leak or moisture coming down a chimney.

Your 'surveyor' should also have given you practical advice on treating the condensation.

Without knowing all the room details, the easiest thing to do may be to fit plasterboard (or thermalboard) on battens to the wall to raise the surface temperature and stop condensation forming. But that may just move the condensation to another surface

However, the condensation should be tackled at source, and you should consider what you are doing to produce the moisture in the air (cooking, bathing, drying washing etc) and what you are doing to extract it (opening ing windows, using fans etc)

dg

[meow2222]

Was it skimmed at the time the dpc was done? If so it may be waterproof plaster, which slows evaporatoin thus makes it wetter, although it takes some time to get wetter.

You dont really give enough information. Is there a chimney there? If so possibly lack of ventilatoin or salt contamination. Leakage from roof is also a possibility. However probably the number 1 suspect would be too high interior RH, which is corrected by looking at what else has been done with hte property to modify its damp handling abilities, and by reducing damp input at sources. Really theres just not enough info in your post to pin it down any fuirther.

NT

[Stuart Noble]

Assuming this is the ground floor party wall, is the corresponding upstairs wall also damp?

[Dave Liquorice]

Agree, properties with solid walls have cold walls(*). The normal cause of interior condensation is lack of ventilation, normally caused by the installation of double glazing.

No drying of clothes over radiators or on drying racks or if you do make sure there is ventilation (open a window a bit). Bath rooms and kitchens to have extractors that are used. The difference changing our cooker hood from recirculate to "dump outside" made to the downstairs humidity was very noticeable. Must fit an extract to the bathroom sometime, upstairs suffers from condensation.

(*)Great in the summer, keeps the place cool. Great in the winter, keeps it warm but what ever you do don't let it cool down as it'll take days to warm back up.