|
:: Rising Damp ::
Rising Damp can be described as the vertical flow of water up a permeable wall structure, in buildings which have no existing damp proof course or failure of any existing damp course.
Before the problem is diagnosed as rising damp, we must first look at other possible sources of moisture other than ground water rising up the wall.
A few other possible causes of damp are:
- Rainwater ingress, water getting through to internal walls via defective external plumbing/pointing etc.
- Bridging plaster, where the plaster internally or externally is below the damp course, causing a bridging effective over the damp proof course for the water to travel up.
- High ground level, external ground level is higher than the damp proof course, causing lateral penetration (Common in a basements).
- Blocked Cavity, Cavity filled up with debris causing bridging effect from outer leaf to inner leaf of cavity.
- Condensation.
- Cracked or broken external rendering.
There are many other possible causes of damp in buildings. This is why you need a specialist surveyor as rising damp can be very easily mis-diagnosed, this cannot be over-emphasised. This can then prove very costly as the problem may come back. There have been cases where companies have had to re-do a damp course over 3 times, then when a specialist surveyor inspected, realised it was not rising damp, but condensation or rainwater ingress which was the problem, and a damp course was never necessary. This does not happen at Marsden Preservation Ltd.
|
:: Condensation ::
Condensation is very commonly confused with rising damp. It is very important to correctly diagnose the problem before a solution is reached. If the problem was not properly diagnosed, and say for example a damp proof course was inserted, the problem would still return.
One of the biggest giveaways with condensation is black spot mould, and the smell. Rising damp does not cause a black mould and does not smell. Condensation does.
How do I get condensation?
Whether or not you have condensation in your house all depends on the environment, whether your house is hot or cold etc. The best thing to do to avoid condensation is to keep your house warm and keep a good airflow.
Common spots you may find condensation are behind long curtains, behind a tv, near the shower/bath, above where the kettle boils etc. This is because hot air gets trapped (e.g. behind curtains) and as their is no airflow, cools down and condenses on your wall. Below is the process of how you get condensation on your walls:
1. Evaporated water is released and is held in the air
2. The hot air expands and rises to ceiling height holding a lot of water
3. On the way, the hot air often condenses on windows or mirrors, which is why they often look steamed up
4. The hot air eventually starts to cool and starts to come down, eventually it will reach "dew point", which means, as the air has cooled down, it has decreased in volume and can no longer hold the moisture
5. If the house is usually cold then condensation could be a big problem as the structural walls will be colder therefore causing the water in the air to condense if they come in contact, explaining how you get condensation on your walls.
6. Black spot mould is formed if conditions are right. The spores produced by black spot mould can cause problems such as triggering asthma, producing cold-like symptoms, and causing damage to personal belongings.
If your walls are warmer then condensation will be less of a problem as the warm air will not have any means of cooling down and reaching dew point, as the walls will be warm and so will the atmosphere
|