'Warm Front' Cavity wall insulation

sgriffiths

As our house is constantly damp, mouldy and generaly full of mildew (total pain), which would be our best option a new damp proof course or cavity wall insulation (currently offered free to myself by 'Warm Front' the government backed insulation people). I dont want to increase the amount of mouldy walls we suffer from, I would like to be rid of them.

Thanks

WestonDave

A damp proof course will only help with rising damp - you will probably be able to identify if this is the cause as it will be worse downstairs (nearer the source of the damp) and more localised (i.e. near the broken parts of the old course). Condensation damp will be more widespread and will be worse in rooms where moist air is generated - kitchens bathrooms and bedrooms - this will not be helped by a new damp proof course, but maybe helped by cavity wall insulation if backed by proper ventilation.

Assuming its condensation damp - you are trying to stop the warm moist air resulting from human activity, hitting a cold wall, condensing moisture which then forms a breeding ground for mould. Sleeping with the windows shut is a prime way to cause mould on the coldest surfaces in the room (single glaxed windows will be the first target, then cold walls, and then double glazed windows if the cavities have been insulated). Likewise having a nice hot steamy shower, or boiling up your food with all the windows shut will leave a load of moisture in the air, which will condense back into water as soon as it hits a cold enough surface. Warmer air holds more moisture so wall insulation can help the walls be less cold and therefore cause less condensation, but its not a miracle cure - you have to sort ventilation as well. It may seem madness to be paying for heating to let it out of a slightly open window, but if you have insulation it will easier to keep the house warm so a bit lost to gain fresh drier air is a more economic prospect.

sgriffiths

We live in a detached bungalow,but I think the problem is caused by condensation like you say. We have two dehumidifiers, one in bedroom wardrobe and a large one in the dining room. I think that we will get cavity wall insulation and hope for the best, maybe renew the double glazing in the back bedrooms (was there when we bought the house 14years ago).

Thanks for your input, have reassured me that my thinking was correct.

WaveyDave_2

are you sure you have cavity walls? The problem you describe would be expected with solid walls more than cavity. As has been said, sounds like you have a ventilation problem, which is causing your condensation, the moisture in the air is condensing when it hits cold surfaces, eg windows/outside walls etc.

Have you thought of putting vents/fans in?

sgriffiths

We have extractor fans in both bathrooms and one over the cooker in the kitchen. I believe that the walls do have cavities, saw them when we recently had a wall knocked down and moved.

Also A neighbour in the same street and type of bungalow had cavity wall insulation done a couple of years ago. My husband put vents in all the bedrooms about 5 years ago, no difference.(when cavity wall insulation is put in, wont it come out through these vents?)