It is important to be able to tell the difference between damp caused by condensation and damp caused by other factors, such as rising damp, rainwater coming in, defective plumbing or poor drainage. Some damp is caused by condensation. Condensation occurs when moist air comes into contact with a colder surface like a wall, window, mirror etc. Condensation tends to get worse in cold weather. The other types of damp (apart from plumbing leaks) tend to get worse in wet weather. Condensation tends to form patches of mould with blurred, soft edges rather than a stain mark. The air can't hold the moisture and tiny drops of water appear. It also occurs in places the air is still, like the corners of rooms, behind furniture or inside wardrobes.
Dampness is a major problem for many houses and flats. Dampness can cause mould on walls and furniture and make timber window frames, floors and skirting boards rot. It also encourages the growth of house dust mites and can increase the risk of respiratory illness. It can also damage wall plaster and may also give rise to dry rot.
Easily confused, rising damp and condensation are both things which you might find in your home. However, while one can be relatively easily remedied before too much harm is caused, the other will need more time and investment to banish it from your home. Some damp is caused by condensation, which is the most common type. For other kinds of damp, see below.
Condensation occurs when moist air comes into contact with a colder surface like a wall, window, mirror etc. The air can't hold the moisture and tiny drops of water appear. Water vapour in the air can be naturally occurring from weather conditions, respiration from human beings, and even plants. You can’t see it, but it’s there in your home. The water vapour floats merrily around your house, and is fairly innocuous. It’s only when it comes into contact with something cold that it starts to become more troublesome.
When it hits something cold, like a window or a poorly insulated surface, the water vapour drops in temperature, and loses some of its strength. It can no longer hold onto its water content, and lets it drop onto the colder surface. This deposited water is what you see when you notice condensation. You can expect to see condensation on any surface where the cold air of the outside world comes into contact with the warmth of your home. Windows and thin, poorly insulated walls are the usual locations you can expect to see condensation.
Condensation can result in black mould. Black mould, or Stachybotrys, is a naturally occurring fungus which helps Mother Nature break down items such as vegetation and return it to the soil. Unfortunately, this mould does not recognise the difference between the inside of your house and a mouldy apple – it just finds the humidity provided by condensation.
There are steps you can take to reduce condensation -
1. Ensure Washing Machine Is Correctly Vented
2. Dry Clothes Outdoors
3. Close Kitchen & Bathroom Doors
4. Use Pan Lids When Cooking
When cooking ensure that you cover your pans with a lid to reduce moisture being created from the water boiling. Also, ensure you are using an extractor hood if you have one above the cooker or an extractor fan if you have one installed, these are designed to help reduce moisture created when cooking.
Remember, don’t turn off your extractor fan as soon as you finish cooking as the moisture can still be in the air even when you have finished, instead leave it on afterwards for 10-15 minutes to help to clear the humid air. Another option is to purchase an extractor fan with intelligent humidity sensors which speed up when you start boiling water and slow down once humidity levels have returned to normal.
5. Turn On Extractor Fan When Taking A Shower
6. Stop Using Portable Gas & Paraffin Heaters
7. Cover Up Fish Tanks & Aquariums
8. Wipe Down Cold Surfaces
9. Don't Overfill Wardrobes & Cupboards
10. Move Furniture Away From External Walls
Unfortunately such pre-cautions will have little affect on rising damp.
Rising damp is different to condensation, although it may have the same appearance. Imagine a sponge being dipped into a bath tub full of water. Water travels up through the sponge as the sponge sucks the water in. House bricks placed onto damp ground behave in the same way as this sponge, sucking up the water from the wet ground around them, in an upwards motion, hence the name “rising damp”. Bricks and masonry keep on sucking up water until gravity dictates that it can’t carry itself up the masonry any more, usually at around 1.2 metres, and the damp levels just build up in the affected area.
Much like the black mould on condensation afflicted walls, the wet areas involved in rising damp also attract the spores of the Stachybotrys mould, and that may be the first sign you notice that you have a rising damp problem. You may also notice the damage from the outside of your home, with a tell-tale tide mark on the exterior bricks.
Don’t confuse rising damp with other common types of damp though. Ground floor level walls can suffer from a similar condition, penetrating damp. Common in cement rendered homes, or those where the cavity walls have been filled, penetrating damp is the result of trapped damp which cannot escape, or an increase in water vapour which overwhelms the few escape routes in a home.
If you’ve got a chimney, you may notice “salt dampness” from long-term water ingress. A giveaway is if you can see weeds and plants growing on your chimney stack, meaning there’s enough water there to support organism growth. Naturally occurring minerals and salts in the air travel through the wetness in the building, and appear on internal walls as brown staining.
The good news is that there are really simple products out there which can remedy condensation and damp problems, and the ventilation experts at Envirovent can help you install them to remedy any damp issues you have in your home. With filterless extractor fans for your bathroom and kitchen, or specialist loft based installations to keep the air in your house clean and mobile, damp and mould won't be able to build up. If the air moves, the damp cannot set in, and there is no way mould will find a home in your house. Speak to the team at Envirovent today to find out which solution is most appropriate for your house. Nobody knows ventilation like Envirovent.
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