- Cavity Wall Crisis -
Prevention is cheaper than the cure
We are getting hundreds of calls from homeowners complaining about a sudden increase in black mould in their rooms, wardrobes, and carpets. Water starts to run down the walls where it never did. Timber begins to rot. Wall ties corrode. Family members suffer from asthma where they never did before. Water runs down windows. Wallpaper starts to peel. Heaven forbid, damp starts to appear everywhere.
THE DAMP PROBLEM
When retrofit cavity wall insulation is installed into a property that is located or built in a way that means it should not have the cavities filled or if the work is undertaken incorrectly, the first and most obvious sign of a problem is almost always internal dampness.
Most homeowners are blissfully unaware if cavity wall insulation hasn't been installed correctly. They don't know if it is over-packed, underfilled, where it has slumped, where areas have been missed, vents have been blocked, or obstructions missed. This is because even though the energy savings won’t be as advertised, there is no visible sign of any defect. Those that are aware of a problem with the insulation within the walls will almost certainly have been put on notice with the appearance of dampness within their home.
DON'T HAVE CAVITY WALL INSULATION
Condensation creates damp conditions which often soak insulation. We are now getting many calls from people who have had cavity wall insulation - their house is getting colder and colder. The reason is simple. Cavity walls were designed to breathe. The original concept of cavity walls was intended to be used in coastal areas where windblown rain was a problem and soaked house walls. It then became standard construction everywhere. Rain hits the outside wall, and it is able, because the wall is only single brick, to get through. It then runs down inside the cavity and exits via the bottom. Airflow in the cavity keeps things nice and dry.
Remember, dry things don't conduct heat. Wet things conduct and lose heat very easily. If your cavity is then filled - you completely destroy any chance the house has of staying dry. Water can easily get through the outer leaf, and it soaks the cavity fill. Condensation from the house also gets through the wall on the inside - and instead of wicking away through the cavity, it finds a nice fluffy mess of waste paper or waste cotton. It all gets wet. And it stays wet. So now, your house has wet walls, and a much greater ability to lose heat through the walls - once upon a time, they were nice and dry. Now they are wet, so they are colder.
OTHER PROBLEMS WITH CAVITY WALL INSULATION
Most cavities should be 'tied' with brick ties. If they stay dry, they don't rust. The wall remains secure. Cool...
Now then - you fill the cavity, and it gets wet. The brick ties get wet and stay wet. And they rust. So the wall is no longer tied together, and it can bulge or fall. Not so Cool...
Cavity insulation also makes a lovely environment for little critturs - lots of lovely mice nests, rats, you name it - they love the stuff. The man from the cavity wall insulation company will tell you it's treated to stop them. Rubbish. Have you ever seen a mouse eat plastic? They do... I've seen them eat their way through bags of building chemicals in our store - and keep eating. It just doesn't affect them. There's virtually nothing that will stop a mouse from eating and making a nest. Cavity walls full of fluffy paper or cotton are a paradise for them. All of this action also makes the insulation settle. Some areas will have none; others will have lots. This makes your walls very prone to being damp or cold in some spots, and not in others - so you start to experience random problems with damp.