Plaster walls are made by nailing strips of narrow wood lath, spaced 1/4 inch apart, horizontally across the vertical studs. Plaster is then pressed onto the strips of lath board with sufficient force to drive it through the 1/4 inch spaces and cause it to mushroom out behind the lath. This mushroom effect holds the plaster wall in place. This building technique results in a wall that's difficult to drill through and chips easily. To anchor heavy shelving to plaster walls, use toggle bolts. They spread the weight-bearing pressure out from the point where the shelving is secured to the wall.
Plaster Walls With Available Studs
Locate the vertical studs in the wall where the shelving will be located by sliding an electronic stud sensor over that space. Mark both side edges of each stud. Plan to position the shelves so that the support brackets will be located over the centers of the studs.
Place one of the brackets against the wall at the first shelf location. Place a carpenters level alongside the bracket and adjust the bracket until it is plumb (perfectly vertical). It may be necessary to set a carpenters level on top to level an irregularly shaped bracket. Mark through the bracket-mounting holes onto the wall with a pencil.
Drill a pilot hole through the plaster and into the stud at each mark, using a drill bit that is slightly smaller than the bracket mounting screws.
Position the bracket on the wall and fasten it to the stud with long wood screws driven into the pilot holes.
Place the second bracket on the wall and lay the shelf on top of both brackets. Lay the carpenters level on the shelf and adjust the bracket until the shelf is level. Drill pilot holes and install it with wood screws into the stud.
Plaster Walls without Available Studs
Mark the locations of all of the bracket mounting holes onto the wall, using a level to make sure the brackets will be level with each other.
Drill a small pilot hole with a wood-boring bit into each mark made through the mounting holes for each bracket. The pilot hole prevents the plaster from cracking and makes drilling the next larger hole easier.
Drill a larger hole to the diameter indicated on the package label for the size of toggle bolt you are using.
Insert a toggle bolt (just the threaded bolt without the anchor wings) through each mounting hole in the shelf bracket, then thread the wings onto the bolts about 1/4 inch. Fold the wings flat against the bolts and insert the wing ends into holes in the wall, pushing in the bolts until the wings clear the wall surface and snap open. Pull the head of the bolt back toward you to ensure it is gripping the wall firmly, then use a screwdriver or drill to tighten the bolt.
Repeat the process to install the remaining bracket(s) for each shelf, then mount the shelves to the brackets.
Back out the screw from the toggle bolt assembly and position the bracket over the hole, insert the screws through the bracket mounting holes into the toggle bolt assembly and tighten them. Continue with this process to anchor the other shelves to the walls.
Things You Will Need
- Electronic stud sensor
- Carpenters level
- Shelf bracket
- Electric drill
- Drill bit, small diameter
- Wood screws, long
- Drill bit, small diameter, wood boring
- Drill bit, larger diameter, wood boring
- Toggle bolts, 2 per shelf bracket
- Wall studs are located on 16 inch centers.
- Ask someone to assist you to hold the shelving in place while you install it.
- Wear eye protection when operating an electric drill.