Damp Proofing Advice
Is that damp or just a stain? Will the house fall down? Or is it safe to ignore it? Damp and damp related problems strike fear into the heart of most homeowners. The temptation is to just close the door on the problem and hope it goes away, but that may not always be the best plan! We have asked damp proofing specialist Ty Fleming of AAA Advanced Damp Proofing to explain a little more about damp problems, why they occur and what can be done to fix them.
Ty, if I suspect damp and call in a damp proofing specialist like AAA Damp Proofing, what can I expect?
The first thing we do is to make a very non-invasive survey. That involves taking readings from inside your walls to establish if the problem is due to rising damp or condensation.
Could condensation really be the problem if I live in a fairly new house?
Absolutely. In fact, new properties are often more prone to condensation due to a combination of poor circulation of air and new UPVC windows with well insulated glass. In older, draftier properties, air was able to circulate through the property and moisture could escape.
When you add that poor air circulation to activities that generate lots of water vapour like cooking, showers, drying clothes on heaters or clothes horses, you have a perfect recipe for condensation. This is particularly the case when kitchens and bathrooms are in close proximity as is common in newer houses or apartments.
Another issue we see in new houses is that they don't have adequate extraction units in the kitchen. They have charcoal extractors which filter the grease and the smells, but return the condensation back into the kitchen.
Finally, we often see problems when extractor fans are used to ventilate a bathroom. Very often, they are undersized in comparison to the size of the bathroom. Apart from spinning in the ceiling, they will achieve very little.
What are the solutions for condensation?
The answer is to create a positive air movement in the property.
The way to do that used to be wall vents. But people are trying to save energy now and putting a vent on your wall is basically putting a hole on your wall and is not energy efficient. In fact, vents may not even solve the problem - they only works if the air has a passage through the house.
Instead of vents, we recommend installing a positive pressure ventilation unit. This will draw air from your loft space which is warm because it's been heated by sun on your roofs slates and move it very slowly through the property. It also has a very small heating element, which kicks in if the temperature drops below 10oC and keeps the air at a moderate temperature. Preventing wide temperature variation will help to eradicate cold spots and reduce the chances of condensation forming in your home.
What about rising damp - what causes that?
Rising damp will occur if the property has no damp proof course or if it has broken down. Lots of older properties, such as red brick facade houses have no damp proof course in them. Or they may at some stage have had a slate bed, or bituminous bed damp proof course. However over time, as the bed expands and contracts with temperature changes and settlement of the property, it breaks down. It's also possible to unintentionally bridge the damp proof course over time by getting in new planted areas or paving and raising the level of the garden.
What is the solution to rising damp?
We will first carry out a survey to determine the exact source of the damp. Then if necessary, we will put in a damp proof course. Injecting the walls is part of that work, but there are some other steps. For rising damp, it's necessary to strip plaster off the walls up to about 1m high. There's no need to go higher than that because, due to capillary action and atmospheric pressure, water will not rise above that level. The wall is replastered in two layers with additional waterproofers and a salt suppressant agent which will provide additional water barrier.
Is wood worm related to damp?
Wood worm in not actually a worm, it's a wood boring beetle. Again, it goes hand in hand with older properties. It can be very aggressive, or just attack once and leave again. It's important to get it treated as they can be very vigorous and I've come across houses where the timber joists have literally crumbled because if wood worm infestation. In any case, nobody likes the ideas of sharing their home with wood boring beetles.
What disruption can I expect if I need to install a damp proof course?
A damp course can be installed in an average house in one day. Where the disruption does occur is in removing the old plaster and replastering again afterwards. However, provided the work is done correctly, keeping in mind that this is some one's home and to treat it with respect the disruption can be kept to a minimum.
What are the new innovations in your work?
The biggest changes are in the materials that we use. For example, the original damp proof course was based on a high pressure, spirit based injection which was flammable of course. The new injection is a low pressure, low invasive cream base which cures in the wall over a period of time. It's a little bit slower but I feel more methodical and give a much better joint throughout the damp course.
What will happen if I don't fix a damp problem?
First problem will be in your energy bills. Water is a very good conductor so if a wall is damp, it loses huge amounts of heat.
The second problem is in the possible knock down effects. Prolonged damp can lead to wet rot and at a later stage possibly dry rot. Dry rot is disastrous for the fabric of the house. It's a fungal growth which will attack both timber and masonry alike . It's good upkeep to make sure your house properly ventilated, warm and dry with no wood boring insects or fungal decay .
Further information
See further information on dry rot and wet rot here..
pickapro.ie would like to thank AAA Advanced Damp Proofing, for their helpful advice and tips for this article.