Sloping stands and summer runoff
When Faerie Glen was established in 1974 it was the city's easternmost suburb, and many homes were built to follow the lie of the land. On a sloping stand, heavy Highveld storms between roughly November and March push a lot of water towards whichever wall sits on the uphill side.
Where paving falls towards the house, or soil is banked against a wall above floor level, moisture can soak into the brickwork. Blocked gutters and downpipes that discharge right next to the foundation make it worse.
The Moreleta Spruit also runs through the area, and gardens close to the reserve tend to be green and well planted. Thick beds against the house, irrigation spraying onto walls and trees planted close to the foundations all add moisture where you least want it, so it is worth looking at the garden as well as the wall.
Telling rising damp from penetrating damp
A tide mark low on an interior wall, bubbling paint near the skirting or a musty cupboard often points to rising damp or water held against the outside. Stains higher up, near window frames or below a parapet, more often come from rain getting in through cracks, failed sealant or the roof.
The fix depends on the cause. Repainting over damp rarely lasts, so a good contractor will look for where the water is coming from before suggesting a damp-proofing treatment, crack repair, improved drainage or roof waterproofing.
Helping the contractor diagnose the problem
Note when the marks appear: after storms, all year, or mainly in winter. Mention which side of the house is affected and whether the ground outside is higher than the floor inside. Photos of the inside and outside of the same wall are very useful.
Send your suburb with the enquiry and the contractor will confirm whether they cover your street.
Faerie Glen: local questions
Our Faerie Glen house backs onto a slope. Can drainage be improved without major work?
Sometimes small changes help, such as re-sloping a strip of paving, adding a channel drain or extending downpipes away from the wall. Larger cut-and-fill or retaining work may need an engineer, and the contractor can advise on that.
Will repainting stop the damp patches coming back?
Usually not on its own. Paint can hide the marks for a while, but if moisture is still getting into the wall it will lift again. The source needs to be dealt with first, then the wall left to dry before repainting.