Condensation in a big house

[Bucketsofdynomite]

Following on from the conservatory roof thread, we've just established that our damp problems are most likely condensation. We've got damp patches in 2 bedrooms and a couple of downstairs rooms so dehumidifiers aren't going to be cost-effective (or environmentally friendly).
Have just bought a condensation trap to try which seems like it will be an ongoing expense x4.
Anyone got any more advice please? How common is it outside kitchens, bathrooms and conservatories?

Oops, forgot to say please, where are my manners.

Condensation (starting as water in the air)travels from warm spots to cold spots. So if you have a shower in your bathroom and leave the door open, the moisture will shift (upwards) and into other rooms. Basic things you can do to reduce condensation if you are not doing this already is:

-dry clothes on a line outside where possible
-if you must dry clothes indoors, then ensure the room has some ventilation to allow the moisture out of the room - it has to go somewhere

• if you use a tumble dryer make sure that it is set up properly so that the moisture is removed from the room (vented) (i don't know much about tumble dryers so not sure what the right terms are
• when cooking, keep lids on pans and the kitchen door shut so the moisture doesn't travel to other rooms
• open the windows of bedrooms and bathrooms for as long as possible each day to allow moisture out

-ensure your bathroom and kitchen is properly ventilated. Either by opening windows or installing mechanical ventilation.

The Dept of Enviornment used to produce a really good leaflet on dealing with condensation which might be worth trying to get hold of.

good luck.

Another thing might be to remove furniture (eg wardrobes) from against outside walls if at all possible as warm moist air gets behind them and then condenses against the cold exterior wall. This can then cause the area behind the wardrobe etc to go really mouldy. Another cause for damp can be pointing on your outside walls that needs redoing, the gaps in the bricks allows moisture in. Also check for cracks in rendering which may not be an obvious source of damp as the area where the crack is on the outside might not correspond to where the damp is on the inside.

You wouldn't necessarily need more than one dehumidifier. You can get one and place it strategically so it can work on the moisture in the whole house. Ebac sell different models for different size houses.

Do you have extractor fans in your kitchen/bathrooms?

Plenty of ventilation.

Don't dry clothes indoors.

Keep the bathroom door shut and window open when you're in there - and allow the fan to run for a good while afterwards.

But I have a fairly large house (4 double beds) and still get condensation sometimes. It doesn't help that the old part of the house has solid walls.

What are your windows like? We live in a Victorian house and have box sash windows which we recently had refurbished. Having windows that "work" has made a big difference - no condensation at all now. Another thing to do is to bleed your radiators to make sure they work properly so that your heating is working efficiently.

Cavity wall insulation might help, I guess, but probably not much...

piglit - where did you get your windows refurbished and how much did it cost per window - if you don't mind me asking?

We have uPVC which actually looks all right as it has 25mm glazing bars to mimic the old style windows, but I'd much rather replace them with proper wooden sliding sash windows.