Repainting Outside This Spring: What to Sort Out Before You Buy Paint
Every September the same thing happens. The weather turns, the outside of the house suddenly looks worse than it did in June, and somebody decides this is the year it gets sorted.
Then the whole project becomes a colour conversation. Which grey. Whether the trim should be darker. What the neighbours did.
The colour is genuinely the easy part, and it is also the last decision you should make. Everything that determines whether your repaint still looks good in five years happens before the colour is chosen. Here is what to work through first.
Why spring is the right time
There is a real window for exterior painting in South Africa and it is narrower than most people assume.
You want the wall dry after winter, the temperature warm enough for the paint to cure properly, and the job finished before the full summer sun arrives. On most inland properties that means roughly September through to early November. Leave it until December and you are painting onto surfaces that have been baking all day, which uses more paint and gives a poorer finish.
So the timing instinct is right. Spring is when to do this. The question is what you do with the weeks before you start.
Walk around your house and actually look
Give yourself half an hour and go around the outside of the house slowly. You are looking for five things.
Rub your hand on a sunny wall. If it comes away powdery, the old paint has broken down. Look at the bottom of the walls for dark patches that have not dried out. Check along the gutter lines and downpipes for paint that is lifting or flaking. Look for cracks, particularly under windowsills. And walk round to the shaded side of the house, which nobody ever does, and look for moss or fungus.
Take photos of anything that looks wrong. A photo on your phone is genuinely useful at the paint counter, because the person helping you can see the surface rather than guess at your description of it.
The damp question, honestly answered
This is the one that catches people out, and it is worth being blunt about.
A wall that feels dry to the touch is not necessarily dry. After a wet winter, plaster can hold moisture well past the point where the surface stops feeling damp. The technical threshold is that a wall should be under 15% moisture content before the top coats go on, and that is measured with a meter rather than judged by hand.
If you paint over a wall that is still holding water, the water has to escape somewhere. It pushes against the back of the new coating, and a few months later you have blistering and peeling on a wall you paid to have painted in September.
There is a second thing worth understanding. If you have damp coming from the ground, or from behind a retaining wall, that is not a paint problem and no paint product will fix it. Prominent Paints Damp Cure is a primer built to handle new plaster that is still drying out, and it copes with moisture up to 40% while a wall dries down to the 15% level. What it cannot do is hold back constant water. If the damp keeps coming back, the source needs fixing first — a blocked gutter, a cracked downpipe, or in more serious cases proper waterproofing.
Fix things in the right order
Cracks are the most commonly bodged part of a home repaint. Filling a hairline crack without opening it first does almost nothing, because there is no room for the filler to actually key into the wall.
The correct sequence is to open the crack to at least 5mm, wash the area with Prominent Paints Fungal Wash, prime with Damp Cure and let it dry for a full 24 hours, fill with Ready Mix Crack Filler, then prime again with Damp Cure and give it another 24 hours before painting.
Two full days of waiting, and both of them matter. It is the least satisfying part of the job and it is the part that determines whether the crack comes back next winter.
While you are at it, deal with the gutters and downpipes. They are the source of a good proportion of exterior damp problems, and there is no sense painting a wall that is about to be rained on from a broken downpipe.
Choose paint for the wall, not the mood board
Different walls on the same house are doing different jobs.
The north and west-facing walls take the most sun and are where colour fades first. The shaded side holds moisture and is where fungus grows. A boundary wall takes road dust and sun on one face. If you live near the coast, everything is dealing with salt in the air, and that changes the recommendation entirely — a standard textured finish that performs perfectly well in Gauteng is a poor choice on the Cape coast.
You do not have to use the same product everywhere. Spend on the walls taking the punishment and choose sensibly for the sheltered ones. This is the single best conversation to have at the branch, and it is free.
Plan the actual weekend
Two rules make more difference to a DIY exterior job than anything else.
Do not paint after three in the afternoon. The temperature drops and the paint does not cure the way it should.
Start on the north-facing walls in the morning and work your way around anti-clockwise. You stay ahead of the sun, you use less paint, and you avoid the streaky finish that comes from painting a hot wall.
Neither costs anything. Both are the difference between a job that looks professional and one that looks like a weekend.
Frequently asked questions
How long should I wait after winter before painting outside?
It depends less on the calendar than on the wall. What matters is that the moisture content is below 15%, which on a well-drained sunny elevation may be reached quite quickly after the last rains, and on a shaded south-facing wall may take considerably longer. If a wall has had a damp problem over winter, give it more time and check it rather than assuming. A meter reading is the only way to be certain.
Can I paint over old paint that is flaking?
Not without removing it first. Flaking paint has already lost its grip on the wall, so anything applied over it is bonding to something that is on its way off. Scrape and sand back to a sound surface, then prime the bare patches before you apply the top coats. It is more work than it sounds and it is not optional.
Do I really need to prime, or can I just use two top coats?
It depends on the surface. Sound, previously painted walls in good condition may not need a separate primer. Bare plaster, patched areas, filled cracks and any wall that has had moisture issues do need priming, because the primer is what creates the bond between an absorbent or unstable surface and the coating above it. Two top coats over a surface that needed a primer is a common shortcut and a common cause of early failure.
What is the difference between damp proofing and a damp primer?
A damp primer such as Damp Cure is designed to let you work on a surface that still carries moisture, typically new plaster drying out, and to protect that surface while it dries. Waterproofing is a system designed to stop water moving through a structure. They solve different problems. If water keeps arriving at a wall, you need waterproofing and probably a repair to whatever is letting it in; a primer will only delay the symptom.
How much paint do I need?
Coverage figures are published on every product’s technical data sheet and vary considerably by product and surface texture. A rough measurement of the wall area, minus doors and windows, will get you close, but textured and porous surfaces use noticeably more than smooth ones. Take your measurements to the branch rather than estimating, and buy slightly over rather than running short mid-wall, since a second batch can vary very slightly in tint.
The short version
Look before you buy. Check the damp. Fix the cracks properly, including the waiting. Choose the product for where the wall is, not for the colour card. Start in the morning and stop at three.
Do those five things and the colour decision, the one everyone starts with, becomes the easy part it always should have been.
Find your nearest Prominent Paints branch on the Prominent Paints website, or call customer care on 0861 77 66 46 for advice on a specific project.