Baseboard and trim, explained

The three pieces that matter most

• Baseboard runs along the bottom of the wall and covers the gap at the floor.
• Casing frames doors and windows.
• Crown sits where the wall meets the ceiling.

They should read as a family. A tall, detailed base with skinny flat casing looks mismatched. Pick the casing first, then size the baseboard to suit it.

Choosing a profile

Modern and newer homes usually suit simple square or slightly eased profiles. Craftsman and character homes suit wider flat casing with a head detail and a taller base. Traditional homes can carry more detailed profiles and crown. When in doubt, go slightly taller and simpler. It rarely looks wrong.

MDF or wood?

Primed MDF is stable, smooth and takes paint well, which is why most painted trim today is MDF. It does not like water, so in bathrooms, entries and basements where floors get wet, a moisture resistant product or wood at the base is the safer choice. Stained trim needs real wood.

Coped vs mitred corners

On inside corners, a mitred joint looks fine on day one but tends to open up as the house moves through wet winters and dry heating seasons. A coped joint, where one piece is cut to the profile of the other, stays tight. Ask your installer how they handle inside corners. It tells you a lot about the job you will get.

Signs of a good trim job

• Outside corners glued and tight with no gaps.
• Baseboard scribed to the floor, not floating over gaps.
• Even reveal on casing all the way around the door.
• Nails set below the surface and filled, not left proud.
• Lines that run straight, even when the walls and ceiling are not.

Do it with the floors

If new flooring is coming, do the baseboard at the same time. New base sits tight to the new floor and covers the expansion gap properly, and you only paint once.