Trim and door painting, where you can see the skill

Identifying what is already on the trim

Older trim in many houses carries oil-based paint. Modern water-based products do not bond reliably to a cured oil surface without preparation, and this is the most common cause of trim paint peeling off in sheets a year later.

Watch for: A crew that does not test or ask. There are simple field checks for an oil-based finish. If nobody establishes it, the adhesion problem is being left to chance on the surface where failure is most visible.

Hardware and fittings removed, not masked

Door handles, hinges where practical, strike plates and switch plates come off. Painting around hardware leaves a visible ridge and gets paint on the metal.

Watch for: Handles taped rather than removed. It is faster and it is the clearest tell that the rest of the job is being done to a schedule rather than a standard.

Cleaning and de-glossing

Trim collects grease, hand oils and dust. It is washed, then sanded or de-glossed so the new coat has a mechanical key, particularly on any high-sheen existing finish.

Watch for: Painting straight over glossy trim. The new coat will look fine and will chip off with a fingernail once cured.

Filling, sanding and caulking

Dents, nail holes and split joints are filled and sanded flush. The gap between trim and wall is caulked to a clean, tooled line — which is what makes the finished trim look sharp rather than approximate.

Watch for: Filler left proud or sanded roughly. On trim it catches light from the side and will be visible from across the room forever.

Priming where required

Bare wood, filled repairs, knots, and any surface being converted from oil-based to water-based gets a bonding or blocking primer. Knots in particular bleed through white paint without a blocker.

Watch for: Knots painted directly. They bleed brown through the finish, sometimes after months, and the only fix is going back and priming properly.

Application — brush, spray, or both

Brushing gives control in place and needs a product with enough open time to level out. Spraying gives a glass-smooth finish and is preferred on doors, which are often taken off and sprayed flat.

Watch for: Spraying trim in situ with inadequate masking. Trim spray in a finished room needs extensive containment, and overspray settles on floors, glass and furniture well beyond where you expect.

Second coat and levelling

Trim almost always needs two coats. Between them, a light sand knocks down raised grain and dust nibs, which is the difference between a smooth finish and a slightly gritty one.

Watch for: No sanding between coats on doors. It takes minutes and it is the single largest contributor to how a painted door feels under the hand.

Rehanging, refitting and cure

Hardware goes back and doors are rehung once the paint has hardened enough not to stick in the frame. Paint stays soft for longer than it stays wet.

Watch for: Doors closed before the paint has cured. They stick to the stops and pull the finish off when opened, on the most visible edge of the door.