How to Install Dado Rail

Tools and Materials

Before You Start

• Mark the rail height using a spirit level and pencil line around the entire room
• Locate all studs (on stud walls) or plan fixing positions on masonry walls
• Plan the layout — start with the longest wall and work around the room
• Prime or paint the rail before fitting for a faster, neater finish
• Measure each wall individually — rooms are rarely perfectly square

Step-by-Step Installation

1. Step 1 — Mark the height line. Measure the desired height from the floor at multiple points. Use a long spirit level to draw a continuous pencil line around the room. This is the top edge of the rail.
2. Step 2 — Measure and cut the first piece. Measure the first wall. Cut the rail to length with square ends for the first piece (it will butt into each corner).
3. Step 3 — Fix the first piece. Apply grab adhesive to the back of the rail in a zigzag pattern. Position on the line and nail at 400-600 mm centres. On masonry walls, drill and plug first. On stud walls, nail into the studs.
4. Step 4 — Cope internal corners. For the next piece meeting at an internal corner, cut a 45° internal mitre, then cope along the profile with a coping saw. Test-fit against the first piece and adjust with sandpaper if needed.
5. Step 5 — Mitre external corners. For external corners, cut matching 45° mitres on both pieces. Glue and pin the mitre joint. If the corner is not exactly 90°, adjust the mitre angle. Apply a small amount of wood glue to the mitre faces.
6. Step 6 — Continue around the room. Work around the room, measuring each piece individually. Join straight runs with a scarf joint (opposing 45° cuts overlapping) rather than a butt joint for an invisible join.
7. Step 7 — Fill and caulk. Punch nail heads below the surface with a nail punch. Fill holes with wood filler and sand smooth when dry. Run a bead of decorators caulk along the top and bottom edges to seal gaps against the wall.
8. Step 8 — Final paint coat. Apply a final topcoat of paint, cutting in carefully along the caulk lines. Use a small brush or angled sash brush for neat edges.

Common Mistakes

• Mitring internal corners instead of coping — mitres open up as the wood moves; coped joints stay tight
• Not checking the level — relying on floor level alone leads to a wonky rail if floors are uneven
• Skipping the adhesive — nails alone can work loose; adhesive plus nails is much more secure
• Not pre-drilling MDF — MDF splits easily without pilot holes
• Forgetting to caulk — gaps between rail and wall look poor and collect dust

Cost Estimate (2026)

Related Calculators

Use the Dado Rail Calculator for material quantities, or the Picture Rail Calculator for similar moulding work.