This guide walks through the common warning signs on siding and trim, what each one usually means, and how they affect the scope of a repaint. A walk around the house on a bright day, looking closely at the sides that get the most sun and weather, tells you a lot.
The signs to look for
- Chalking: a powdery residue that rubs off on your hand
- Fading or uneven colour, especially on sunny walls
- Peeling, flaking or blistering paint
- Cracking or alligatoring in the paint film on trim and wood siding
- Caulk that is cracked, shrunken or pulling away at joints
- Bare or greyed wood showing through worn paint
- Mildew or algae on shaded or damp walls
- Soft spots, swelling or rot in wood trim and siding
Not included
- Damage from a roof, gutter or plumbing leak: fix the source before repainting
Chalking and fading
Chalking happens as sunlight slowly breaks down the binder in paint, leaving loose pigment on the surface. Rub a palm across the siding: if it comes away coloured, the paint is chalking. Some chalking is normal with age, but heavy chalking means the coating is wearing thin and new paint will not bond well until the chalk is washed off and, in some cases, a suitable primer is applied.
Fading usually shows first on the walls facing the strongest sun. It is mostly cosmetic early on, but it tells you how the coating is ageing on that side of the house, and those walls often need attention before the shaded ones.
Peeling, blistering and cracking
Peeling and blistering are more serious, because they mean the paint is losing its grip and water can reach the surface underneath. Common causes are moisture coming from behind, such as from the inside of the house or from failed caulk, painting over dirt or chalk, or paint applied in poor weather. Finding the cause matters, because repainting over the same problem repeats it.
Fine cracking, and the crocodile-skin pattern known as alligatoring, show that the paint film has become brittle, often after many coats have built up. Small areas can be scraped and sanded back; widespread alligatoring may need more extensive removal before new paint will last.
Caulk, bare wood and rot
Caulk joints around windows, doors and trim are the first line of defence against water getting behind the siding. When caulk cracks or pulls away, water can run in and soak the wood. Replacing failed caulk is a routine part of exterior preparation and one of the most valuable steps in protecting the house.
Once paint wears through on wood, the surface turns grey as sunlight damages the fibres. Greyed wood needs sanding back to fresh wood before priming. If wood feels soft when pressed with a screwdriver, or is swollen and split, it may be rotten. Rot is a repair rather than painting, and catching it early keeps it small.
Different siding, different signs
Wood siding and trim show peeling, cracking and greying most clearly. Aluminum siding tends to chalk and fade, and can be repainted after thorough cleaning and the right primer. Fibre cement holds paint well but still fades and needs its joints maintained.
Vinyl siding can be painted, but it needs care: some colours, especially darker ones, can absorb enough heat from the sun to make vinyl warp, so products and colours made for vinyl are used. Stucco and brick have their own considerations, covered in our guide to painting stucco and brick.
Doors, soffits, fascia and the details
Siding is the largest surface, but the details often show wear first. Front doors take sun and hands every day, garage doors get bumped and splashed, and window sills and the bottoms of door frames sit where water collects. These areas are worth checking closely, because they are where peeling and rot usually start.
Soffits and fascia, the boards under and along the edge of the roof, are easy to overlook from the ground. Peeling paint there can point to gutter overflow or moisture from the attic. Because they are high up, it makes sense to include them when the rest of the house is painted rather than bringing ladders back later.
A repaint is also a good moment to rethink colour on these details. A new front door colour or crisp trim can change the look of a house as much as repainting the siding, and the two decisions usually work out better when they are made together.
Questions about repainting siding
How often should I check my siding?
A quick look each spring, after the snow has gone, catches most problems early. Look closely at the sunniest and most exposed walls, the bottoms of walls near the ground and the caulk around windows and doors.
Can I just repaint the sunny side of the house?
Sometimes. If one side has worn much faster, repainting it alone is possible, though a slight colour difference can show where old and new paint meet. Repainting whole elevations to a natural break gives a cleaner result.
Should I wait until the paint is visibly peeling?
It is better not to. Repainting while the old coat is still mostly sound means less scraping and less risk of water damage to the wood underneath.
Is mildew a reason to repaint?
Not always. Mildew can often be cleaned off. If it keeps returning, it points to shade and moisture, and any repaint should start with a thorough mildew wash so it does not grow through the new paint.
How does GOPAINT handle a siding repaint?
Surfaces are washed, scraped, sanded, caulked and primed before the finish coats. We use premium exterior-grade coatings, and the job ends with a full site clean-up.