Preparing for the Rainy Season: A Waterproofing Checklist

Most waterproofing failures aren’t discovered during a downpour, they’re discovered afterwards, when a stain appears on a ceiling or a wall starts to smell musty. By then, water has usually already found its way into the building. Running through a few checks before the rain arrives catches small issues while they’re still cheap to fix.

This checklist covers the areas most likely to let water in, and what to look for at each one.

It’s worth doing this walk-through even on a property that had no issues last year. Waterproofing membranes and sealants degrade gradually with UV exposure and temperature changes, so a roof or wall that performed well twelve months ago isn’t guaranteed to perform the same way again, particularly if it’s approaching the end of its expected lifespan.

Know Your Rainy Season

South Africa doesn’t have one rainy season. Much of the interior, including Gauteng and the Highveld, receives most of its rain in summer, typically October through March, while the Western Cape has a winter rainfall pattern, with the wettest months falling between May and August. Timing your checks a few weeks ahead of your region’s wet season gives enough lead time to act on anything found.

Roof and Gutter Checklist

• Clear gutters and downpipes of leaves and debris so water can drain freely
• Check for ponding water on flat roofs that hasn’t drained within a day or two of previous rain
• Look for cracking, bubbling, or lifting in the waterproofing membrane, especially around joints and flashing
• Inspect flashing around chimneys, vents, and parapet walls for gaps or lifting
• Check for loose or cracked roof tiles on pitched roofs
• Check that any solar panels, satellite dishes, or other roof-mounted fittings haven’t disturbed the surrounding membrane or flashing where they were installed

Wall and Damp Checklist

• Look for tide marks, peeling paint, or crumbling plaster near the base of external and internal walls
• Check external ground levels haven’t crept up over the damp-proof course line
• Inspect window and door frames for gaps or failed sealant where water could enter
• Note any musty smells in ground floor rooms, particularly those with limited ventilation

Below-Ground and Drainage Checklist

• Check that stormwater drains and channels around the property are clear and directing water away from the building
• Inspect basement or below-ground walls for damp patches, efflorescence, or visible cracks
• Confirm that the ground slopes away from the foundation rather than towards it
• Check that any sump pumps or below-ground drainage systems are functioning before they’re needed

After the First Heavy Rainfall

The first significant storm of the season is a useful test in itself. Once it passes, walk through the property again and check for anything the earlier inspection might have missed: new stains on ceilings, damp patches that weren’t there before, or water pooling somewhere it hasn’t previously. Catching an issue after one storm, rather than after weeks of repeated rain, gives far more room to arrange repairs before the problem compounds.

It’s also worth keeping a simple record, even just a few photos with dates, of any problem areas identified each season. This makes it easier to track whether a repair has actually held or whether an issue is recurring in the same spot, which is useful information to share with a contractor if further work is needed.

When to Call a Professional

Landlords and body corporates managing multiple units benefit from running this checklist across common areas as well as individual units, since shared roofs, parking basements, and external walls are often overlooked when responsibility for maintenance isn’t clearly assigned to one person.

A visual checklist is useful for catching obvious problems, but it won’t tell you whether a membrane has failed beneath the surface or whether a damp-proof course is still doing its job. If any of the checks above raise a concern, or if a property has had recurring issues in previous rainy seasons, it’s worth having a professional waterproofing or damp proofing assessment done before the weather turns, rather than during the first storm.

What to Keep on Hand Before the Rain Starts

Beyond the physical inspection, it helps to have a couple of practical items ready: a torch for checking dim roof spaces or ceiling cavities after any suspected leak, and the contact details of a waterproofing contractor saved somewhere accessible, rather than searched for in the middle of a storm when a problem is discovered. If a property has had recurring issues, keeping a record of previous repair dates and locations also makes it much quicker for a contractor to assess what’s changed.

Summary

Rainy season preparation comes down to clearing drainage paths, checking roofs and walls for early warning signs, and confirming water is being directed away from the building rather than towards it. Catching problems before the rain arrives is consistently cheaper and less disruptive than repairing water damage after the fact.

If your checklist has turned up anything concerning, Advanced Waterproofing can inspect and treat it before the rain sets in. Call 010 823 8232, email info@advancedwaterproofing.co.za, or get in touch through our contact page.