Unframed mirrors are a popular, low-cost way to add interest to wall decor. They come in a variety of shapes and sizes that can be used anywhere throughout the home. Finding a glue that will not ruin the silver mirror backing and successfully adhere to concrete, drywall, plaster, painted surfaces and wood is the most challenging part of this easy decorating project. Mirrors are not lightweight, so a strong, heat- and moisture-resistant adhesive is key.
Prepare the wall for the adhesive by priming any porous surfaces, such as unpainted plaster, drywall or concrete, with a quality primer or lightly sanding painted surfaces with a 40-grit sandpaper.
Clean all dust and debris from the wall with a sponge dipped in a 50-50 distilled white vinegar and water mix. Allow the surface of the wall to dry to its normal colour.
Have someone hold the mirror against the wall in the desired position. Use a level to make sure it is straight, and mark the top of the mirror with a pencil line.
Set the mirror with its silver back facing up on a clean, dry work surface.
Cut the adhesive nozzle at the 9 mm (three-eighths-inch) diameter marking with scissors, and puncture the inner seal with a nail.
Place 9 mm (three-eighths-inch) diameter beads of adhesive along the full length of the mirror 127 mm to 152 mm (5 to 6 inches) apart.
Line the mirror up to the marked line and press it against the wall.
Pull the mirror slightly away from the wall to activate the glue, and press it firmly back into position.
Apply painter's tape to the mirror edges to hold it to the wall while the glue dries. Let the glue dry for 24 hours before removing the tape.
For heavier mirrors, a temporary wooden support made from two pieces of board in the shape of a T can support the mirror until the glue dries.