DIY Guide
Install baseboard yourself, start to finish
Eight steps from first measurement to final coat of caulk — including the coping technique that separates a clean inside corner from a gapped one.
Tools & materials
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Measure the room & order material
Measure every wall at floor height and total the perimeter. Subtract door openings, then add a 10% waste allowance for miscuts, coping, and corner loss — the calculator above does this automatically per room.
Let material acclimate
Solid wood, finger-jointed, and MDF baseboard should sit unpackaged in the room for 48 hours before installation so it adjusts to the room's humidity. Skipping this is the single most common cause of gaps appearing weeks after install.
Cut outside corners with a miter
Outside corners are cut at matching 45° angles on the miter saw so the two pieces meet in a clean point. Cut long, test-fit, and trim in small increments — it's easy to remove material, impossible to add it back.
Cope inside corners
Rather than mitering inside corners (which gaps as walls settle), cut the first piece square into the corner, then cut the second piece at a 45° back-cut and use a coping saw to follow the resulting profile outline. The coped piece sits flush against the face of the first, corner and all — and stays tight even if the wall angle isn't exactly 90°.
Dry-fit and mark obstructions
Before nailing anything, dry-fit every piece around the room and mark cutouts for outlets, vents, or door casing. Confirm the whole run closes cleanly before committing glue or nails to a single piece.
Attach and fasten
Run a bead of construction adhesive along the back, then fasten with a finish nailer into wall studs — roughly every 16″ along the run, plus a nail near each end. On uneven walls, adhesive does most of the holding; nails just pull the board tight while it cures.
Fill, caulk, and sand
Set nail heads below the surface with a nail set, then fill holes and any seams with wood filler. Run a thin, paintable caulk bead along the top edge where the board meets the wall to close any gap from an uneven surface, and at mitered outside corners if needed. Sand filler smooth once dry.
Prime, paint, or finish
Spot-prime any bare wood filler, then apply your final coat — paint for MDF, PVC, and primed wood; stain or clear coat for hardwood. Two thin coats outperform one thick one, especially at inside corners where caulk and wood meet.
Common mistakes
Skipping acclimation
Installing wood or MDF straight from the store leads to gaps and warping as it adjusts to the room.
Mitering inside corners
Miters open into visible gaps as the house settles. Coping holds tight even on out-of-square corners.
Nailing into drywall only
Without hitting studs, fasteners loosen over time even with adhesive backing it up.
No waste allowance
Ordering exact linear footage leaves no room for miscuts, coping loss, or a bad angle — order 10%+ extra.
Overfilling caulk lines
A thick caulk bead cracks as it cures. Tool it thin, and let two light passes do the work of one heavy one.
Ignoring wall high spots
Run a straightedge along the wall first — a high spot will hold the board off the floor along the whole run.
Ready to order material?
Get exact linear footage, piece count, and cost before you head to the store.