To fight the problem of damp and moisture efficiently, you first need to find the cause. Flaking paint, moulds appearing, crumbling coatings and cracking walls are all signs that moisture is there. You should take necessary measures before the structure of your property is damaged, which could lead to higher repair costs. Moisture is also the source of many diseases not to mention allergies due to mould and dust mites or even osteoarthritis.
Moisture is treated according to its cause. It is therefore essential to get a diagnosis prior to any treatment. The best way is to call a professional because it is very easy to go wrong as treatments are not the same.
What are the causes and signs of humidity?
There are various factors causing high humidity levels in your home such as condensation, rising damp, infiltrations and accidental causes. The principle cause is condensation: the water vapour contained in the air condenses and turns into water when it touches a cold wall or window. The main signs of moisture due to condensation are: signs of condensation on the windows in the morning, damp walls, fungi (mould) on the walls and at the level of the tile joints.
We talk about rising damp when the soil moisture migrates to the walls (it can reach the floor of the house), in contradiction with the phenomenon of gravity. The main sign of moisture due to rising damp is the appearance of potassium nitrate (KNO3.), a thin white layer deposited on the surface of the walls. You may also noticed the peeling of wallpaper, the decay of rugs and carpets, the erosion of coatings and the appearance of small mushrooms.
The infiltrations are formed by rain water that penetrates into the walls or the roof of the house. This may be due to insufficient sealing of the walls and/or roof, leaking pipes, ageing drain pipes, gutter obstructions, cracks in the walls or the porosity of building materials. Moisture due to infiltration can result in the presence of brown spots on the walls, with paint peeling in places, or by the presence of wet drops on the ceiling. The infiltration also promotes the development of bacteria and moulds.
Various accidents can result in a house being humid: very small pipe’s leak, rupture or blockage of pipes, joints wear, construction non-compliant to standards, etc. Most often, leaks are not obvious and it is not until the signs of damp are noticed that the homeowner starts to investigate.
How to fight moisture?
The value of humidity helps a lot in the determination of the cause of moisture. To measure this you can use an electrical moisture reader. Depending on the moisture content, you can determine the source of the moisture and adopt the adequate treatment. If in doubt, call a professional for diagnosis.
Ventilation is the best way to fight moisture due to condensation. Begin by natural ventilation: install vents at the level of the doors and windows. The choice and arrangement of ventilation influences much about the result. If this is not enough, install a controlled mechanical ventilation (CMV). It is a motorised device that renews the air inside the house. There are single flow CMVs and dual stream ones. The single flow CMV works continuously: install air intakes at the level of rooms’ windows to draw outside air. This air flows pipes and comes out in damp rooms such as the bathroom or kitchen through extraction vents. This system renews continuously the air , which solves the problem of condensation.
Take a few extra steps in addition to ventilation: install a humidity absorber, improve the heat insulation by fitting insulation panels on walls and installing double glazed windows. You can also cover the inner walls with a damp-proofing paint.
For rising damp, injecting a silicone type chemical is a very efficient solution. The product will be laminating, thus preventing the water back into the wall.
Fight rising damp by installing an electro Osmosis box (an electric based system that includes wire and anodes inserted into the wall to divert rising dampness). There is also a device still under trial in the UK which inhibits the passage of water up a wall by inducing magnetic fields.
If the two previous solutions are not possible (too many cracks, not enough homogeneous wall, etc.), you can always have an external or internal perimeter French drain pipe system and sump pump installed. It is the most effective way to collect water building around your foundations and send it away from your basement or crawl space.
For moisture problems caused by infiltrations, consider solutions depending on the causes. For sloping roofs, replace broken tiles. Coat tiles, slates and other bituminized shingles with a waterproofing product using a gun. This product will clog the pores and prevent any infiltration. For flat roofs, coat them with a background layer and then apply a liquid rubber with a roller. The rubber provides waterproof protection. To make a roof waterproof, you can also use associated sealant to the fiberglass. Insert a strip of glass cloth between two layers of putty.
If there is infiltration inside walls, act according to the damage. For barely visible cracks (less than 0.2 mm), use a water repellent treatment. For larger cracks, use elastic putty and then apply a waterproof coating on the wall. If the wall is painted or coated, apply a base coat and then paint the wall with a water sealant product. The product must be diluted and applied with a brush. Wait a few hours and then apply a second coat of the same product but undiluted. If the wall is made of brick or stone, apply several coats of sealant using a roller. Repeat the operation until saturation.
If the problem lies at the level of the gutter, start by removing all the waste that are there and make sure that water flows properly.
During the winter and cold months, you should try to keep a constant temperature in your home. This is because it is cold air that causes the warm air to release moisture. If the air is all the same temperature then this cannot happen.
Remember if in doubt always call in a professional to assess the problem and to carry out any required work.