INTERNAL WALL PROBLEMS
Most problems with internal walls, including the inner skin of your external walls, will be caused by water. Let’s look at penetrating damp, rising damp and problems caused by faulty plumbing.
l As a basic rule of thumb, damp below waist height is rising damp and above that is considered penetrating damp. But as we know life is never easy, and penetrating damp can start from anywhere above floor or damp-proof course level.
l Penetrating damp is caused by water, either rain or from garden sprinklers, being driven against exterior walls by wind, or even just the strength of the sprinklers. It will also be more prevalent in houses with solid walls as distinct from cavity walls. Cavity walls are designed with a space between the outer and inner brickwork of about 50mm. The idea is that any water penetrating the outer skin will run down the cavity and exit at weep holes (gaps left in the brickwork) at floor level.
l Remember, gardens and flower beds should always be at a lower level than the floors inside your house and garden sprinkler systems are meant to water your garden and not wash down the walls of your house. Without your noticing it, your garden against the side of the house will slowly get higher, so make a point of marking the inside floor level on the outside and ensure that nothing is within 50mm of this point, or above the bottom of the weep holes if you have cavity walls.
l Check to see that all irrigation sprinklers are positioned and set so that water is spayed away from the walls and be careful with the hosepipe. Water will penetrate cracks that are hardly visible to the naked eye. While I was still contracting we often had to prove this to clients by holding a hosepipe against the suspect wall – water would find its way through hairline cracks within minutes.
l If you want flower boxes around your house, ensure that the back wall of the box is separate from your house; this will prevent moisture migrating through the brickwork. If you have existing flower boxes either have them removed or ensure that they are properly waterproofed with a material that will not perish underground.
l Contact me at don@macalister.co.za or SMS only to 082 4463859. - Weekend Argus