How To Install Glass Fireplace Doors

Unlike gas fireplaces that you can turn off, wood fireplaces require proper containment. Glass fireplace doors prevent sparks from falling on your floor, reduce drafts and heat loss when the fireplace isn’t in use, and allow you to enjoy your fireplace safely while adding style to your home. This guide will walk you through the process of installing glass fireplace doors, making your hearth both safer and more attractive.

Can You Add Glass Doors to a Fireplace?

Many modern fireplaces come equipped with glass doors, but retrofitting them to an existing fireplace is a viable and relatively straightforward option. Glass doors are available in standard sizes that fit most flat firebox openings.

For this installation guide, we consulted Justin Calemmo of Five Sons Chimney Service in Brookfield, Connecticut. He demonstrated how to retrofit new doors on an 1848 fireplace with an undersized surround. In this case, the glass doors enhance safety and also protect the nearby wood floor and mantel from the fire’s heat.

Fireplace Glass Door Installation in 8 Steps

Installing glass fireplace doors is a matter of fitting the door unit into the firebox opening and securing it to the masonry. The process is relatively simple for squared-off brick fireboxes. However, if your firebox contains rough, textured material, such as fieldstone, standard doors may not be suitable since they have trouble overlapping the opening’s edges.

When working with older fireplaces, exercise caution when drilling into the brick, as it may be brittle. Always use appropriate safety gear, including safety glasses and work gloves, throughout the installation process.

Step 1: Attach Lintel Clamps to the Door

Begin by standing the door on its bottom edge, leaning it against your leg or having a helper hold it steady. Using a Phillips head screwdriver, remove the four screws located on the back of the door where the floor brackets (bottom) and lintel clamps (top) attach. Set these screws aside for later use.

Next, assemble the two lintel clamps and attach them to the top of the door frame. Ensure they’re properly aligned and fastened. These clamps will secure the top part of the door to the lintel running across the fireplace.

Step 2: Adjust the Clamps

As you tighten the screws holding the lintel clamps to the upper rear frame of the doors, note that they fit into a slot milled in the clamps. This slot allows for vertical adjustment for precise alignment with the underside of the lintel.

After securing the lintel clamps, attach the two L-shaped floor brackets to the bottom of the door frame. These brackets will anchor the door unit to the firebox floor. As you proceed, double-check the alignment to ensure a perfect fit.

Step 3: Mark for Screw Holes

Carefully position the door unit into the firebox opening, taking care not to scratch the finish—it should fit snuggly into the opening. For better visibility, hang a droplight inside the firebox to illuminate your work area.

While holding the unit in place, reach inside to mark where the bottom brackets meet the floor of the firebox. Using a thick marker, mark through the grooves in the brackets for accurate placement.

Step 4: Drill Holes for Lead Anchors

Gently remove the door unit from the firebox and set it aside. Using a drill/driver fitted with a 5/16-inch masonry bit, drill two-inch-deep holes at each of the two bracket marks. Always drill into brick, not mortar, as mortar crumbles easily and won’t provide a secure hold for the anchor. Drill straight down to avoid difficulties when inserting the screw later.

The drilling process requires a steady hand and precision to maintain the stability of the door unit. Take frequent breaks to prevent overheating the drill bit, ensuring your work remains accurate.

Step 5: Insert Lead Anchors for Screws

After drilling, use a wet/dry vacuum to remove all dust. Then, take a lead anchor and, using a hammer, gently tap it into each hole until it’s flush with the surrounding brick surface. These anchors will provide a secure base for the screws that will hold the door unit in place. Properly installed anchors ensure the stability and durability of the door.

Step 6: Insulate the Door

Put on a pair of gloves to protect your hands, then unroll the fiberglass insulation provided with the door unit. Tear off pieces to fit into the channels at the sides and top. Stuff the insulation into all three channels.

Unlike wall insulation, it’s not necessary to keep the fiberglass fluffy. Its primary purpose is to seal the door, preventing smoke from seeping out and protecting the door frame’s finish from heat damage.

Step 7: Screw the Door to the Firebox Floor

Carefully slide the door unit back into the firebox opening, double-checking that no insulation is visible around the frame’s edge. Make sure the door is flush with the face of the firebox for a proper fit.

Reach inside and insert sheet-metal screws through the bottom brackets and into the lead anchors. Using a socket wrench, tighten the screws to secure the unit to the brick. Don’t over-tighten the screws, as this could loosen the anchor in the brick or break the screw head.

Step 8: Clamp the Door to the Lintel

The final step involves securing the door to the metal lintel bar at the top of the firebox using the adjustable clamps. Position the clamps to span the depth of the lintel.

Finger-tighten the thumbscrew to clamp the hardware onto the lintel. Once you can’t turn the thumbscrew any further by hand, use a pair of pliers to give it another quarter-turn.

Maintaining Your Glass Fireplace Doors

Regular maintenance can keep your newly installed glass fireplace doors in top condition. Here are a few ways to maintain your glass fireplace doors:

• Clean the glass regularly using a fireplace glass cleaner to remove soot and residue.
• Inspect the gaskets and seals annually, replacing them if they show signs of wear.
• Lubricate the door hinges and handles as needed to ensure smooth operation.

Fireplace Glass Door: Safety Considerations

While glass fireplace doors enhance safety, it’s important to use them correctly to reduce the risk of a fire. Here are a few glass safety tips to keep in mind:

• Always keep the doors open when starting a fire and while it’s burning to allow for proper airflow.
• Close the doors only when the fire has died down to embers.
• Never leave a fire unattended, even with glass doors installed.

Fireplace Glass Doors: Our Conclusion

With the right tools and techniques, most homeowners can install glass fireplace doors in a few hours. The result is a more efficient, safer fireplace that adds elegance to your living space. This relatively simple do-it-yourself (DIY) project can result in a safer fireplace and reduce drafts and heat loss, making it a valuable addition to any home.