To install fireplace doors, gather a screwdriver, hammer, marker, socket wrench, pliers, electric drill fitted with a 5/16-inch masonry bit and glass door kit. Install lintel clamps for doors to the wall, insulate the door and clamp door to lintel.
Installation of fireplace doors requires assembling and attaching the lintel clamps to the top of the door with the screwdriver. Adjust the clamps up or down to ensure they are aligned with the lintel’s underside running across the firebox opening top. Screw the L-shaped floor brackets to the bottom of the door.
Fit the door unit to the firebox opening. While holding the unit in place, use the marker to mark where the bottom brackets meet the firebox floor. Remove the door from the firebox opening and drill 2-inch deep holes at the two bracket marks. Remove any dust in and around the holes with a vacuum. Gently drive a lead anchor into each hole until it is level with the surrounding area.
While wearing a pair of gloves, unroll the fiberglass insulation and tear it into pieces that fit the channels at the top and sides of the door unit. Slide the door into the firebox opening while making sure that the insulation does not stick out. Twist the sheet metal screws through the bottom brackets and into the lead anchors. Tighten the screws with the socket wrench. Finger-tighten the thumbscrew on the clamp onto the lintel and use the pliers for another quarter turn.