The methods of fixing the different types of support vary slightly, but the general principles are the same. Remember to check, when deciding where to place the shelves, that you will not be drilling into electric cables or water pipes. Cables to socket outlets normally run up from the floor, while those for light switches normally run down from the ceiling; but to be safe, don’t drill holes in the wall either vertically above or below these fittings. Plan the position of the shelves, taking into account the height of objects to be stored and allowing a little extra space above. Also check you will be able to reach the top shelf easily. Lightly mark with a pencil the position of each shelf on the wall. When fixing the shelves in position, use these marks only as a preliminary guide; always check with a spirit level to ensure they are truly horizontal.
This traditional system is probably the simplest of all. A timber batten is screwed to each side wall of a recess and the shelf is laid across. For extra support across a long span, fix a batten to the back wall too. To make the battens you can use softwood or off cuts of the shelf material, such as chipboard. For a lightweight shelf intended to display a few ornaments, you could use 25 x 12mm battens. For large books or heavy kitchen utensils, use 50 x 25mm battens. For medium loads, use timber between these two sizes. Screws Use 50mm No 6 screws for a lightweight job, 63mm No 8 screws for medium weight shelves and 75mm No 10 for a sturdy assembly.
Cut out both side wall support battens a little shorter than the width of the shelf. Drill a countersunk clearance hole 25-50mm from each end of the batten, depending on the length of the batten and mitre or bevel the front edges of the battens so they will be less noticeable. If using a back batten, cut it to the width of the recess minus the thickness of one of the side battens; cut the thickness of the back batten off the straight end of the other side batten. Drill holes at not more than 300mm intervals. Position the first side wall batten at the required height. Rest a spirit level on top to check the batten is horizontal and mark with a bradawl or nail the positions of the holes onto the wall. Remove the batten and drill the holes in the wall to the required depth. Insert wallplugs or cavity wall fixings, depending on the type of wall involved. Place the batten in position again and partly drive in the fixing screws. Check the horizontal again with the spirit level before finally driving the screws home. If you are using a back batten, line it up so its top edge is level with the top of the side wall batten already fixed. Place the spirit level on top to check the batten is horizontal. Get someone to hold it in place while you mark the screw positions on the wall as before. Drill the holes, insert plugs (or other wall fixings) and drive in the screws, checking again the batten is horizontal. If a back batten is not being fixed, use a straightedge and pencil a line across the back wall level with the top edge of the side batten; use a spirit level to check the straight-edge is horizontal.
Line up the second side wall batten with the pencil mark, checking the horizontal with the spirit level. Fix the second side wall batten in the same way as the first, making sure its top edge is aligned with the back batten or pencil line. Position a squarely cut scrap piece of shelving on the battens in both corners of the recess to check the side walls are square. If there is a gap between the end of the shelving and the side walls, you will have to cut the shelf to fit. The back of the shelf may also need shaping and this must be done first. Pin a length of card or stiff paper onto the back wall batten so it fits exactly into each corner. Using a small block of wood and a pencil trace the outline of the back wall onto the template. Cut along this line carefully, tape the template onto your piece of shelving and transfer the outline. Then use two smaller pieces of card and mark on them the outline of each side wall in turn, following the same procedure.
Measure from each corner diagonally across to the proposed front edge of the shelf on the opposite side wall, making a small allowance for the trimmed back edge of the shelf before determining the width of the shelf. Position each side wall template carefully in turn on your piece of shelving. Starting with the left hand side wall, place the back left-hand corner of the template to coincide with the left-hand end of the already marked shelf. The angle of the template will be determined when the front left-hand corner of the template coincides with the length of the diagonal from the opposite corner. Tape the template onto the shelf in this position and transfer the side wall outline onto the shelf. Working from the opposite end, repeat this procedure for the right-hand side wall.
This will give you the correct outline for yow shelf, which can then be cut to shape. Place the shelf on the battens; it can be loose laid, screwed or glued and pinned in position.
Using angled metal strips
These serve the same purpose as battens, supporting the shelves against the side walls of an alcove. Screw holes are often provided, so you just need to mark the position of the screws on the wall with a pencil. Place a spirit level on the horizontal part of the strip to check the strip is level. Screw in place as for battens, using a screw size to match the pre-drilled holes and ensuring at least 38mm of the screw will be in the wall. If you wish, you can make a recess in the edge of the shelf so the top of the metal strip will be invisible when the shelf is in position. Place a bracket on the shelf side edge and draw round it with a pencil to mark the cutting lines. Chisel out to the required depth with a paring chisel, grooving plane or electric router. Stop the recess just before the front edge of the shelf, so the bracket will be concealed. Recess the other end of the shelf in the same way, fit the angled strips to the side walls of the alcove and slide the shelf on to them.
Using L-shaped metal angle brackets
These can be bought in various sizes; the arm of the bracket should extend almost to the front edge of the shelf to give full support. Some brackets have one arm longer than the other, in which case you must fix the longer arms to the wall. To fix the brackets, place a straight-edge in the required position, check with a spirit level and draw a line along the lower edge where you want the shelf to be. Measure and mark off the intervals at which you want to place the brackets, putting the end ones a short distance in from the ends of the shelf. Fix the two end brackets in place first. Hold the first bracket in place on the wall, checking the horizontal and vertical with a spirit level. and mark the screw positions with a pencil. Screw in place as for battens, using screws to match the pre-drilled holes. Before fixing the second bracket, hold it in position and check it is level with the first by placing a straight-edge on top of the two brackets and putting a spirit level on it. Do the same with intermediate brackets. When all the brackets are in place, lay the shelf in position and mark the screw positions through the holes in the brackets onto the underside of the shelf. Drill pilot holes to take the screws, replace the shelf on the brackets and screw it in place.
Using timber angle brackets
Strong home-made brackets are ideal for a garage or workshop where strength is more important than appearance. The brackets are made by fixing two pieces of wood at right-angles and inserting a brace between them to form a triangle. Use 25 x 12mm softwood for medium loads and 50 x 25mm for heavier loads. Cut one length a little shorter than the width of the shelf and another length about 50mm longer than the first; this will be fixed vertically to the wall. Fit the lengths together at right-angles using a halving joint and glue; screw through the joint. Position another length of wood across the right angled piece so it forms a triangle, placing it about 50mm from the end of the horizontal. Mark countersunk clearance holes where the third piece of wood meets the inside edges of the other two sides of the triangle; mark the two sides and join up these marks across the top and bottom to give you your cutting lines. Cut the brace timber to the exact length, checking the brace fits exactly when you place it inside the right-angle. Drill three countersunk clearance holes in the vertical batten and two in the horizontal batten; the size of the holes should correspond to the recommended screw sizes. Screw the bracket to the wall and fit the shelf in place, drilling pilot holes for the shelf fixing screws. Finally glue and screw the angled piece in position with countersunk screws.