Niggles around the house tend to reveal themselves in the wet season: leaking roofs, blocked gutters, poor drainage, mold and – of course – moisture in the walls.
Chances are, the unsightly post-winter bubbles and flakes of wall paint are driving a few homeowners up those very walls. Jacques Marais, expert advisor at AAA Paint, shares a few pointers on fixing the problem.
Determining the cause of the wall damp will give you an idea of how easy (or hard) it will be to stop the absorption of moisture.
In many older houses, damp rises from the foundations in the absence of a damp course (usually a thick layer of black plastic underneath the brickwork). Moisture near the top of a wall may come from roof leaks or a parapet that is cracked and lets in rainwater. Dampness around mid-height is likely to come from unsealed windows.
Fixing the cause
Unfortunately, damp that rises from beneath is not an easy thing to fix and it will require the help of costly specialists.
When damp comes from higher up, however, a good hardware store will have everything you need. Click here to read one of our previous blog posts on how to fix roof leaks. Cracks in the parapet should be filled and the whole surface given a pure acrylic waterproofing coat.
Remove old silicon from window frames and reseal them with a paintable, stretchable polyurethane silicon. Your waterproofing primer should then be painted over both frame and wall to seal the entire contact area.
Choosing the right primer
Waterproofing primers come in three different classes: 18%, 30% and 40% moisture tolerance. The higher the moisture content in the walls, the higher the necessary percentage reading of the primer (and, unfortunately, the higher the cost).
Primer will also neutralise an excess of alkaline salts in the walls, which causes a white powdery substance on the surfaces of the walls.
Measuring the moisture level
It is impossible to determine the moisture content with the naked eye (although you might be able to take a guess). AAA Paint offers moisture readings as a free service to customers who visit the store for product. Feel free to enquire about a house-call by one of our experts.
Finishing the job
Once you have fixed the leaks and had the moisture measured, you can prepare your walls for painting by sanding down the bubbles, flakes and other loose particles, and then removing dust by wiping the surfaces with a clean, damp cloth. Apply your selected primer first, always followed by two coats of paint.
Safeguard the wall on the rainy side of the house by adding a layer of waterproof paint in between the primer and first top coat. Jacques recommends Elastocryl, a stretchable specialised product made from a natural raw material as tough as nature had made it.
Lastly, a reminder of the golden rule of home improvement and maintenance: Price and quality go hand in hand. Ask AAA Paint’s in-store experts for assistance if you want to ensure you choose the best product for the job – a little advice can go a long way.