A wood fireplace gives atmosphere to a room, but most of its heat is lost through the chimney. A fireplace heat shield helps protect the masonry inside a firebox from heat damage. There's also a reflective quality to a heat shield that sends more of the fireplace heat into the room. Heat shields install easily to improve wood fireplace efficiency while preserving the fire bricks.
Measure the height and width of the back wall of the firebox, using a measuring tape. Use a heat shield that is at least 1 inch narrower and 2 inches shorter than the back wall.
Remove the grate from the firebox and sweep out the ashes and coals with the broom and shovel fireplace tools.
Place the curved base of the shield plate into the slots of the leg supports. Fireplace heat shield legs typically have three choices of support slots that each lean the shield plate at a different angle. Choose the slots that lean the shield plate at the same angle as the firebox back wall.
Place the heat shield into the firebox as close to the back wall as possible. Put the grate inside the firebox against the heat shield.
Have the chimney inspected by a professional chimney sweep each year at the start of the cold weather season. Moderate wood fireplace users will need creosote build-up removed from the chimney every two years. Frequent users should have the chimney cleaned annually.