How to Fit a Dado Rail (and Make Sure it’s Straight!)

First of all, you will have to decide on a suitable height for the dado rail.

It doesn’t want to be either too high or too low. For example, on a recent project the dado rail was fitted at a height of 37 1/2″ (950mm) to the top edge with a room ceiling height of 116 1/2″ (2450mm).

When you have decided on a suitable height, check the dado will look okay from an aesthetics point of view – check where it meets up to your fireplace, window ledges etc.

Mark the chosen height from the floor at approximately 3 ft (1000mm) intervals around the room and in each corner.

Now check these marks with a spirit level (you can always use a spirit level and a straight length of timber) and mark a pencil line around the room.

Hopefully, the line will be as near as level.

If the marks are only 1/4″  (6mm) or so out, this can be lost across the length of the dado as long as it meets up with the next piece of dado at the corner.

If the levels are out by a greater margin then you can either mark a level line all the way around the room from a set starting point, eg the fireplace, or use a self-levelling laser line like the one below, to ensure the guidelines are perfectly straight.

Cut mitre joints for corners

At each corner, you will have to cut an internal or external mitre. This is best done using a mitre box as dado rail comes in assorted profiles that are virtually impossible to mark for a freehand cut.

It’s worth putting a small pencil mark on the piece of dado to be cut at the angle the mitre will be as it’s easy to cut a mitre internally instead of externally or vice versa by mistake.

If the wall is longer than the lengths of dado available then cut one internal and one external mitre in each length at the joint, this can be held together with small nails or panel pins with the head left below the surface and finished off with filler later. 

The cuts can be made with a fine-bladed handsaw or as I prefer a hacksaw again with a fine blade (22 teeth per inch) which gives a nice clean cut.

The cut edges should be lightly sanded with fine sandpaper and don’t worry if the mitre isn’t perfect, if the dado is being painted it can be filled with an appropriate filler later. 

How to fix the dado rail to the wall

To fix the dado to the wall you have two choices:

1. Screw and plug it into the wall countersinking the holes so the screw head is below the surface and can be later filled and therefore hidden or,
2. Use a good quality adhesive such as No More Nails. If you choose this method, the wall surface should be clean and wallpaper-free. The adhesive is applied to the dado rail with a silicone gun and when it is placed in position knock some panel pins underneath the bottom edge so it doesn’t drop down and out of level.

When the dado is attached to the wall, fill any small gaps in your mitres and along the top edge of the dado rail with decorators caulk using a silicone gun to give a great finish that’s ready to paint.

Tools required for fitting a dado rail

For measuring, preparing and finishing

• Tape measure
• Spirit level (and maybe a long piece of timber) or a laser level
• Handsaw or hacksaw with a fine-toothed blade
• Mitre box
• Fine sandpaper
• Decorators caulk

For fixing the dado rail to the wall

• Drill (if you don’t own a drill yet, check out this drill buying guide for beginners)
• Screws
• Screwdriver, electric screwdriver or cordless drill
• Countersink drill bit
• Wood filler

or

• Strong adhesive such as No More Nails
• Silicone gun
• Panel pins
• Hammer