When paint peels, people blame the paint. Almost every time we get called out to look at a failure, the paint was fine — it was applied to a surface it could never have bonded to, or over a moisture problem nobody dealt with.
Here are the three causes, in the order we actually find them.
1. Moisture coming from behind
This is the big one, and no coating survives it. Water getting into the wall — a leak, failed flashing, a bathroom with no working fan, or grade sloping toward the house — pushes paint off from the back. You will see it as blistering or as sheets lifting cleanly away with the back of the paint still smooth.
That last detail is the tell. If the back of the peeled paint is clean rather than carrying bits of the surface with it, the bond never failed — the water broke it. Repainting before fixing the source is money set on fire, and any painter worth hiring will tell you so.
2. Prep that was skipped
Coatings need something to grip. Painting over grease, chalking, dust, or an existing glossy finish gives them nothing, and the result can look perfect for a season before it lets go.
In kitchens it is cooking grease. On exteriors it is chalking — that powdery residue on old paint that is the binder breaking down under UV. On trim it is old polish and hand oil. All of it has to come off, and any remaining gloss has to be scuffed so the new coat has a mechanical key.
- Wash and degrease before anything else
- Scuff sand glossy surfaces so the new coat can bite
- Scrape failing coating back to a sound edge and feather it
- Prime bare, patched, and stained areas — never colour straight over filler
3. The wrong primer, or none at all
Primer is not a cheaper coat of paint. It is a bonding layer chosen for the specific substrate, and using the wrong one is as bad as using none.
Bare wood needs its knots sealed or they bleed yellow through white. Oak needs a stain-blocking primer for the same reason. Water stains need sealing or the tannins come through weeks later. Vinyl, metal, and thermofoil need bonding primers rated for them. Stucco needs a masonry coating that lets moisture out — ordinary house paint traps it and comes off in sheets, which is the most common exterior failure we see in Alberta.
How to tell which one you have
None of these are fixed by better paint. They are fixed by finding the cause first, which is the whole reason a proper quote starts by looking at the surface rather than quoting from the driveway.
- Peeling in a bathroom or kitchen, or one localised patch: suspect moisture
- Peeling in sheets off stucco: the wrong coating was used
- Chipping off cabinet edges and around handles: degreasing was skipped
- Yellow or brown bleeding through white: no stain-blocking primer
- Failure concentrated on south and west walls: UV plus prep, usually both