New Government schemes which promote the use of insulation, and make us install loft and cavity wall insulation are causing huge problems with condensation.
The Perils of Loft and Cavity Wall Insulation
We are getting hundreds of calls from home owners complaining about a sudden increase in black mould in their rooms, wardrobes and carpets. Water starts to run down walls where it never did. Timber begins to rot. Roof timbers become saturated. Family members suffer from asthma where they never did before. Water runs down windows. Wallpaper starts to peel. Heaven forbid, Rising Damp starts to appear everywhere.
My question is always this: What did you do to change the house? The inevitable answer: 'Oh - we got a Government Grant to put in loft insulation' or 'We got a grant for cavity wall insulation'. As I have said before - BEWARE of anything or anyone that claims to offer grants, or free insulation - You don't Get Owt for Nowt - there is ALWAYS a catch!
So now we know what's causing all this damp. Insulation. The house is warmer. Parts of it are now colder as a result - especially the roof space. Warm air can hold more water - boil a kettle and see. You cant even see steam - hot air - until it condenses. So where is all that water going to? The answer is simple - into the fabric of the house - wallpaper, carpets, timber, windows, clothes. Things that are damp become a breeding ground for fungi and bacteria, which is what the 'damp smell' is that you complain about.
So what is the solution? That increased humidity has to be reduced. We need to be far more aware of humidity and condensation. We need to manage the air in our house - more ventilation, more de-humidifying processes - humidity controlled extractors, bigger air vents, more open windows, more fireplaces that are open and venting, and so on. You cannot have insulation without increased humidity, unless you control the things that produce water - like humans breathing, cooking, showering and so on.
If you need to reduce or control humidity, you need to look at using proper humidity controlled equipment which need not be expensive, but will take the guesswork out of the equation. Email us here for more information on Humidity Contol Equipment.
Do Not 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 designed 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. As Alexandr Meerkat says: "Simples :-)"
Now of course, the salesman for the company that blows in the insulation will get very upset at all this - he and his company are in cahoots with the Government grants scheme which is throwing millions of pounds of taxpayers money down the toilet - they don't want you to stop buying their waste paper that they are being paid to dispose of in your walls. You MUST investigate their claims - ask the man from the Cavity Wall Insulation company to prove that these things don't happen. Get them to guarantee that the cavity will always stay dry. Get them to guarantee that the wall ties will not rust. They won't - they will run a mile. Quite often its the same companies that are making the injection damp proofing chemicals. Nasty people, who should all be pushed off a cliff.
Have a read of Jeff Howell's blog about CWI - respected columnist for the Sunday Telegraph:
Confusion over Cavity Fill - The Facts!
Other Problems with Cavity Wall Insulation
Most cavities should be 'tied' with brick ties. If they stay dry, they dont rust. The wall stays 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 down. 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 its 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 doesnt affect them. Theres 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.
So... Cavity Wall Insulation is Bad.... Very Bad... and it will potentially cause structural damage to your home.
This does not stop you from insulating your home.. There are other, very acceptable and proper ways of doing it which we explain elsewhere on the site - but NOT in the cavity - please!
Loft Insulation Causes Condensation and Rots your Roof Timbers!
This is another major problem which is starting to affect more homes, as the Government Word gets around, and our nasty insulation companies are promoting free insulation, paid for by the taxpayer. DO YOUR RESEARCH - check the claims the insulation companies make. Research their websites - look for the negatives, the problems - dont just read the "Thank You - our house is nice and warm now" letters that clients send the next day before the damage sets in.. It's all very simple. Trap heat into the house with loft insulation. The house gets warmer, and more moisture is absorbed into the air in the house. This warm moist air rises. It is not totally stopped just by a load of insulation - it eventually makes its way, loaded with moisture, into what is now a very cold loft space. Whoopee! All that nice warm, moist air then condenses all over the bottom of your roof tiles, and runs down the felting. If you've got that horrible black bitumen based felt - condensation just LOVES the stuff - it runs down, drips everywhere, and more importantly SOAKS the roof timbers themselves - so that especially in winter, you get mould, fungus, and rotting timbers. I often do surveys nowadays in which I find rotting and mouldy roof timbers as a direct result of loft insulation being installed. There is nothing wrong with loft insulation as a concept - BUT - the roof space needs to be well ventilated to take account of the increased humidity - airflow needs to be increased dramatically to stop condensation damaging the structural timbers. If you have very modern felt - the monarfil type, which is breathable, the problems will be less - but loft insulation tends to be sold into older homes, which by their very nature have older, bitumen based felt which can't breathe.