Condensation: Symptoms & Cures 

Condensation is a complicated subject and you can read a much fuller article   HERE

However, most people just want to:

A) Recognise it

B) Know how to cure it…

So here goes:

Recognition…some symptoms:

Mould growth, very often black, but not always; usually appearing in corners, window reveals or behind large pieces of furniture, such as beds or wardrobes.

Other places where mould appears are on cold spots on any wall or above a window. I’ve also seen it on bedroom ceilings, where they meet the walls, usually because the loft insulation has been installed such that it doesn't fully cover the ceiling areas beneath.

It usually forms on north and easterly facing walls or those that are shaded from the sun by adjacent buildings or structures. Large trees can shade your house too.

Damp areas are seen on walls and, in some cases, such as windowpanes, gloss-painted walls or vinyl-covered floors, water droplets form. In the latter case, it can even form a film on the surface of the floor, which can be slippy. Incidentally, it can occur on double as well as single-glazed panes, given the right conditions.

Your wallpaper may start to peel, and in serious cases, the paint and plasterwork can deteriorate to the point where it falls off (see the photographs on the Introduction page).

Material on clothes in the wardrobe or upholstery on chairs can form mildew.

The salt and sugar start to solidify in their containers (if they're open to the atmosphere).

Favourite places are bedrooms, kitchens and bathrooms but it also occurs frequently on the lower reaches of ground floor walls, especially at the wall/floor junction, where it masquerades as ‘rising damp’, thereby deceiving men with moisture meters and clipboards, otherwise known as damp proofing contractors!

Cures:

Better ventilation: use trickle vents on windows; try not to block fireplaces; don’t install double-glazing. Oh! You already have…Ah well!

Incidentally, most double glazed windows have a trickle vent setting: open the window fully and then close it again to within +/- 10mm of its fully closed position. You should then be able to operate the handle and lock it in this position, i.e., with a small gap between the frame and the opening light.

You might not fancy this at ground floor level because it gives your friendly neighbourhood burglar a good levering point, but upstairs it’s not so bad!

Indulge in longer periods of heating, perhaps with the thermostat set lower than you otherwise would, so that cold walls absorb heat for longer. Just turning up the 'stat for the same length of heating cycle probably won’t work.

Keep the door closed when you have a bath and make use of the extractor fan (not for agitating the bath water you understand). Also, to keep the steam down: run the cold water into the bath before you run the hot.

Similarly, when you’re using the kitchen for cooking or washing clothes etc - close the door. Leaving it open allows moist air to spread throughout the house.  You want to rid the room of moisture but this shoud be via the fan or the window, not the living room.

Don’t dry clothes inside the house if at all possible (I know, I know); and if you have a tumble dryer, make sure it’s vented to the outside.

Insulate the house: Consider cavity wall insulation; or if you have solid walls and a really bad condensation problem, dry-lining the external ones with insulation (and a vapour barrier) included. I have a PDF I send to people if they want to know how to do this. Just email me and I'll send you a copy.

A ‘final resort’ is to install a positive pressure fan in the loft – expensive but it may solve your problems. Absolutely do not: use calor gas or paraffin heaters.

(The black mould referred to is usually Aspergillus niger and has been linked to respiratory diseases and allergic reactions. Clean it off with a mild solution of bleach and water. Anti-fungicide paints are available at decorator’s merchants. There's a website dedicated to this organism, which you could Google for). 

You can buy anti-mould kits from Biokil Crown Ltd.  Their website, www.biokil.co.uk has details; look under 'Anti Condensation Products'.

Now, if you really want to lose the will to live, read the long article...