Straightforward to put up, a dado rail can improve the proportions of a wall as well as adding decorative impact by allowing different wall treatments above and below it.
A dado rail is made up of lengths of wooden molding fixed at about waist height to the wall around a room, in a hallway or up a flight of stairs. A simple dado rail has a molded front and flat back, and straight ends that you have to miter to fit neatly into the round corners.
Different thicknesses and designs are readily available from timber merchants and major DIY centers. Softwood rail is cheaper than hardwood and easier to saw. As well as dado rail molding, you can buy a prescribed and pre-mitered kit rail that clips on to plastic fittings screwed to the wall.
The best way to fix a dado rail to the wall is with screws and wall plugs. If you use masonry nails you risk damaging the plaster, especially if the plaster is unsound. Even it you nail up the rail without any trouble, when you come to remove it you may find the plaster comes away from the wall with the rail. One alternative with a flat wall is to use panel adhesive to stick the rail to the wall.
You can stain, paint or varnish a dado rail in the same way as any other internal wood work. Sand the rail before you cut it up, but leave the decorating until you have fixed the whole rail to the wall.
Work out how much rail you need to buy by measuring the length of the walls and adding a bit extra for wastage. To ensure there are no joins in conspicuous places, lay the rail on the floor along the walls, starting at a window or door frame, and work out where best to make cuts and joins. To prevent wasteful cuts, try to avoid placing joins just before corners, or on narrow stretches of wall where one length of rail could go right across.
To fix a dado rail you will need:
Dado rail
Steel tape measure
Spirit level
5mm wood and countersink bits and drill
Bradawl
Masonry drill bit and wallplugs
50mm No.8 countersunk woodscrews
Screwdriver
Try square
Miter box
Tenon saw
Coping saw
Cellulose filler and fine sandpaper
1. Marking the guideline: Lightly mark the height of the lower edge of the rail at intervals along the wall in pencil, usually 3 feet (90cm) above the floor. Use a spirit level to mark the true horizontal between these points lightly on the wall in pencil. Continue the line round the room, checking its level as you go.
2. Drilling the rail: Using a 5mm wood bit, drill holes through the rail at about 18 inch (45cm) intervals, finishing them off with a countersink bit.
3. Drilling the wall: Hold the rail against the wall, aligning the lower edge with the pencil line. Mark the wall through the holes with a bradawl. This is easiest if someone holds the rail for you. Remove the rail and, using a masonry bit, drill the fixing holes in the wall at the marked points, then insert wallplugs.
4. Screwing on the rail: Again an extra pair of hands is helpful at this stage. Screw the rail to the wall at both ends first, checking with a spirit level that it is perfectly horizontal before securing. Then put in the screws in between. Don’t start at one end and work you way along as the rail might slip from the true horizontal.
Joining rails: Butt join two lengths of rail end to end where they meet on the wall. To make sure that both ends are cut absolutely square, mark the cutting line with a try square or use the central straight slot in a miter box.
External corners: External corners need to be mitered. Lay a piece of scrap wood in the bottom of the miter box so that you can cut clean through the rail without cutting into the box. Position the rail in the box, lining it up at least 1 inch (2.5cm) beyond the angles slots. Saw through it with a tenon saw, making sure you are cutting the miter the correct way round. Cut the rail very slightly too long rather than too short and trim the other end to an exact fit as gaps are difficult to conceal.
Internal corners: Mitering is the easier method for fitting internal corners when using very intricate molding. Cut the miters the other way round to an external corner following the instructions above.
For simpler molded profiles, you can butt the straight end of one rail flush with the wall and scribe the other to fit over it. To scribe a rail, lay the strip molded side down and hold the end of a spare piece of rail against it at right angles. Draw round the profile in pencil, then cut to shape with a coping saw.
Finishing the rail: Fill countersunk screw holes with cellulose filler, or use plastic wood if you want to set then sand smooth. Where necessary, fill and sand smooth joins and corners. Then decorate with the finish of your choice, using masking tape to protect the wall.
Kit rail has pre-cut grooves in the back that slot over plastic clips screwed into the wall so there are no screw holes to fill later. The rails are pre-scribed with interlocking ends for joining lengths and fitting into interior corners. Pre-mitered rail for external corners is sold separately in two short lengths.
A kit rail is particularly useful if your walls are uneven, because plastic clips prevent any undulations in the wall producing steps in the face of the molding profile at joins. Where walls are uneven you can space the plastic screw fittings closer together to lift the rail over any bumps.
1. Fixing the clips: Measure up and mark the position of the rail as before. Draw a second line parallel to the first, approximately 1 3/8 inch (3.5cm) from the top or bottom of the rail, to mark the center line of the groove in the back. Using a masonry bit, drill fixing holes at 16 inch (40cm) intervals along this line on a straight wall. Insert the wallplugs and screw the clips to the wall.
2. Clipping to the wall: Using a length of rail and spirit level, check that the clips are lined up straight and level. Hold the rail up to the clips, so that the prongs pivot on the groove. Press the rail firmly in place, giving it a sharp blow with the side of your fist to force it over the clips.
3. Joining kit rails: Fix a double clip where two rails join, positioning it midway across the joint to hold the interlocked scribed ends together closely and smoothly.
Internal corners: Cut the end straight off one rail to butt it into the corner flush with the wall. Then choose a rail with an interlocking pre-scribed end and press it into the molding along the adjacent wall.
