Refresh an outdated fireplace by covering the old brick with plaster. The plaster technique completely covers brick, including the indented mortar lines. The finished plaster may be painted any colour using latex paint. The finished plaster look is permanent and cannot be removed. Schedule several days for the project because several layers of plaster are required to smooth the plaster over the brick. Always practice the technique before plastering the permanent surface.
Clean the brick to ensure that the plaster bonds well to the surface. Use a scrub brush and warm soapy water and remove all dirt from the brick. Allow the brick to dry about a day. Touch the brick; if it feels cool, more drying time is needed.
Apply painters tape to all adjoining surfaces touching the brick, such as the mantle and nearby walls. Burnish the tape by rubbing it down with an old credit card or plastic trowel. Place plastic dust sheets around the fireplace to cover and protect the flooring.
Paint the brick with a bonding primer made for stone surfaces. Use a mini roller and apply two coats of the primer. Use a chip brush to paint hard to reach areas with the roller. Two coats are required because the first coat of primer will be absorbed by the brick. Ensure all areas of the brick are covered. Allow to dry one day.
Use a drywall trowel or a large putty knife to fill in the brick grout lines and texture. Apply lightweight joint compound to the brick surface by holding the tool at a 30 degree angle and scraping in the plaster over the surface. Allow the plaster to dry. Sand lightly with a medium grit sanding block. Wipe with a damp towel to remove all plaster dust. Repeat the plaster technique three to four times to fill in all texture created by the brick until a smooth surface is created.
Paint the final coat of plaster with two or more coats of paint. The first coat of paint will be absorbed by the plaster. Remove all painters tape and remove all plastic sheeting. Cut the painters tape with a razor blade if the tape is difficult to remove due to dry plaster.
When painting plaster a dark colour, such as red, paint the surface a dark grey first.
Always open all windows and doors when painting and using plaster to avoid breathing fumes. Use latex gloves to protect your skin and nails from paint and plaster.