Brackets Ease Shelf Installation : Hardware: It’s possible to do professional-looking job using the proper materials and taking time to align them on the wall.

Specially designed hardware for installing shelves--brackets and standards with adjustable brackets--help the average homeowner achieve a professional-looking job.

Here are directions for installing shelves using a variety of hardware.

Shelf brackets, designed to support a single shelf, are available in a wide variety of sizes. Simple L-shaped brackets are most common. You can also get ones with decorative or plain bracing between the legs on the L.

For maximum strength, attach brackets with the longest leg on the wall and secure them to the wall studs. Brackets attached to wallboard or plaster with hollow fasteners are more likely to pull out. Studs in most homes are spaced at 16-inch intervals.

To find them, look for clues such as wallboard scars or electric boxes nailed to studs. You can also drill a tiny hole at an angle into the wall and run a wire through it until you hit a stud.

Shelves for heavy loads should have their support brackets held by long screws going well into each of the wall studs at 16-inch intervals. Keep overhangs at each shelf end to 8 inches or less. Lighter loads can be held by supports screwed into every other stud at 32-inch intervals.

Limit shelf overhangs to no more than 12 inches. Masonry walls require inserting either expansion shields or lead anchors. Again, space the brackets every 16 inches for heavy loads and every 32 inches for lighter loads.

To install brackets:

1. Position one bracket on the wall. Use a level or a combination square to check that it is vertical. Mark the position of the screw holes. With a bit that’s slightly smaller in diameter than the screw, drill screw holes. Screw the bracket to the wall.

2. Measure and mark the position of both brackets on the shelf. Then drill holes and screw the second bracket to the shelf. Make sure it is square and even with the shelf’s back edge, and be careful not to drill all the way through the shelf.

3. Position the shelf on the wall and check that it is level. Then attach the second bracket to the wall. Finally, attach the first bracket to the shelf.

One of the fastest, least costly ways to install wall shelves is to use standards--vertical wall supports that accept moveable brackets. Slotted metal standards with wedge-shaped brackets are most common, but many other types are available, including heavy-duty metal standards with double rows of slots and decorative wood standards.

To install a standard:

1. Find a screw hole near the middle of the standard and mark its position on the wall over a stud.

2. Using a drill bit that’s slightly smaller than the screw, drill a hole. Attach the standard but don’t tighten it.

3. Adjust the standard’s position until the bubble in a carpenter’s level shows that it’s perfectly vertical. Then mark and drill holes for the other screws and finish attaching the standard.

If you don’t have a level, mount the standard loosely from its top screw and let it swing back and forth. When it stops moving, it will be plumb. Install the bottom screw and tighten both screws.

On a masonry wall, it’s difficult to install anchors that precisely match the holes on a shelf standard. It’s easier to secure a 1-by-3 to the wall with cut or masonry nails and then screw the standard to it.

4. Put a bracket on the standard and in the matching slots of another standard. Hold the second standard against the wall over another stud and put a shelf on the brackets. Level the shelf, then put up the second standard the same way you did the first.

Hint: When planning the shelves for standards, investigate adjustable-angle brackets for a magazine or book rack and long brackets for a desk or a cabinet.

To strengthen a shelf, attach a 1-by-2 or a larger wood strip along its front edge. Or, consider putting a strip under its rear edge or providing support from below at mid-span.