How to Cover a Fireplace Hole [Temporary + DIY Covers]

The US Department of Energy notes that the typical American homeowner incurs as much as $275 in annual energy expenses due to air leaks through unsealed masonry fireplaces. That’s why it makes financial sense to block your fireplace opening if you don’t intend to use the hearth for the foreseeable future. So, how do you temporarily cover a fireplace hole?

Should I block a fireplace opening?

Fireplaces and chimneys- when left open- leak out lots of hot air while letting in cold air into the house. This can lead to high energy bills as you spend more energy to heat up your home. It’s, therefore, crucial to seal/block a fireplace opening if it’s not currently in use. Blocking a fireplace opening can either be a DIY job, or you can call in the professionals.

What can I use to cover an unused fireplace?

Fireplace covers

Installing a fireplace cover/fireplace screen door on the fireplace opening helps prevent warm air from escaping out of the house. Fireplace doors come in a variety of designs, and can either be temporary or permanent.

Fireplace dampers

The damper is a metal valve located within the chimney. It works to prevent drafty airflow when the chimney isn’t in use. If you still have cold drafts leaking into your home even when the flue damper is closed, it could be that it’s too worn out. The best solution, in this case, is to replace the damper with a new, effective one.

Flue sealers

Chimney flue pipes provide much-needed ventilation for masonry fireplaces. However, since old-school dampers tend to allow cold drafts to leak into the house, flue pipes typically need to be sealed, especially if the fireplace is not in use.

Flue sealers are usually installed underneath the damper to keep out cold drafts and keep in hot air.

To effectively seal off your flue opening, you can install a polyurethane chimney balloon sealer or a silicone rubber flue pipe sealer. Inflatable chimney plugs/ balloons not only prevent air leaks, but also prevent critters and debris from entering your house. Silicone fireplace sealers- on the other hand- feature durable construction and can last for up to 20 years.

Fireplace inserts

Heath inserts are combustion systems that improve the energy efficiency of fireplaces. The steel/cast iron construction helps to prevent air from escaping. Meanwhile, some inserts feature blowers that drive warm air back into the house via the front vents. Electric and gas inserts are also incredibly easy to operate. All you have to do to turn them on is push a button.

Fireplace vent covers

A screen door or an insert may not be enough to fully prevent air leaks through your masonry firebox, as the vents on the lower and upper sections of the frame still allow for air to pass through. Thus, to completely keep cold air outside and hot air inside the house, we recommend covering these vents using a fireplace vent cover.

Chimney caps

A chimney cap is an air-tight, removable cover used to seal the chimney flue opening. Standard chimney caps are cheaper and only seal the flue opening.  Meanwhile, custom-sized chimney caps are more expensive and are usually mounted outside the chimney to cover both the chimney crown and top.

Fireplace blankets

This type of hearth covering boasts fireproof construction and uses magnetic technology to attach to the metal screen of the fireplace.  A good quality fireplace blanket will effectively keep hot air in while simultaneously stopping downward cold drafts.

Fabric draft stoppers

A fabric draft stopper is a rectangular tube that features pliable construction and is designed to close off gaps at the base of fireplace doors and screens. They also keep out smoke.

DIY fireplace covers

If you don’t have the money to invest in a fireplace screen door or a flue sealer, you can improvise using a DIY fireplace cover. There’s a wide range of unused materials around the house that you can use to create a fireplace cover by yourself. For instance, that old barn door, plywood board, or stained glass window lying idly in your garage could work out just fine as a DIY hearth covering.

How to cover a fireplace hole

The main consideration when choosing a cover for your fireplace opening is its ability to prevent air leaks. Another important consideration is the visual aesthetics of the cover, as the fireplace is usually a focal point within the house and draws lots of attention. Finally, you want a cover that you can easily uninstall whenever you want to use the fireplace again. Therefore, blocking the opening with bricks is not an option.

That being said, the best temporary cover for a fireplace opening is a screen door/glass door. To properly install a fireplace door, follow the general procedure detailed below:

1. Gather the tools you’ll need

Before starting out on this project, make sure all the equipment and supplies you need for the project are close by. These include fiberglass insulation, a screwdriver, a power drill, a hammer, clamps, pliers, protective gloves, wrench tools, and sockets.

2. Mount lintel clamps and floor brackets to the door

Using a screwdriver, unfasten the screws at the back of the door. Then, attach two lintel clamps at the top of the door, and the floor brackets to the bottom part. Secure both the lintel clamps and floor brackets using the four screws that you’d earlier removed.

3. Mark out your screw holes

While positioning the fireplace door against the hearth opening, mark out the spots where you’ll drill your screw holes for the floor brackets.

4. Drill holes for lead anchors

Using an electric drill and a 5/16-inch drill bit, drill two-inch deep holes in the spots that you’d marked out during the previous step. Next, install the lead anchors for the screws into the holes using a hammer. The anchors should be level with the brick surface.

5. Install door insulation

Once your lead anchors are in place, it’s now time to insulate the door to prevent smoke leaks. With your protective gloves on, unroll the fiberglass insulation and stuff it into all three channels of the door to insulate it.

6. Secure the door to the fireplace floor

Next, screw down the door to the firebox floor by simply driving the screws through the brackets and lead anchors. Then, tighten the screws using a wrench tool.

7. Clamp the door to lintel

Finish off your fireplace hole cover installation project by hand-adjusting the clamps that secure the lintel bar to the hearth. You can then tighten the thumbscrew using a pair of pliers.

Best Temporary Fireplace Covers

Fireplace Blocker firebox blanket

This fire-resistant hearth blanket from Fireplace Blocker effectively prevents drafty airflow via the fireplace opening. It measures 32-inches high and 42-inches wide, thus will effectively cover the opening of a standard-sized firebox. The Fireplace Blocker features magnetic construction that allows it to easily adhere to your fireplace screen.

ARTZONE Tiffany Fireplace Screen

Improve your firebox’s energy efficiency with the Tiffany fireplace screen from ARTZONE. Measuring 28-inches high and 43.6-inches wide, this screen sheet does a great job at covering up your fireplace hole. The three-panel fireplace screen door will not only ward off air leaks, but also improve your hearth’s visual aesthetics due to the detailed stained glass patterns.

Pleasant Hearth AT-1002 Ascot Fireplace Glass Door

The AT-1002 Ascot Fireplace Glass Door by Pleasant Hearth offers both functionality and aesthetic appeal. Due to its black finish and transparent glazing, this hearth door is the best option if you have a fireplace with a modern, minimalist aesthetic and are looking for something that matches it.

Available in dimensions of up to 43-inches wide and 32.5-inches high, this fireplace glass door is large enough to cover all standard-sized fireplaces. Meanwhile, the bifold doors allow for easy closure to prevent air leaks when the hearth is not in use.

When to seal a fireplace

The best time of the year to seal a firebox that’s been lying idle is in late fall- just before winter. This is the beginning of the coldest season of the year and chimney draftiness is more likely to occur. To prevent cold drafts from seeping into your house during winter, temporarily seal your fireplace using a chimney balloon, firebox opening cover, or a chimney flue cap.

References

  1. https://www.energy.gov/energysaver/weatherize/air-sealing-your-home

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