How do I cover my fireplace for winter?

As the weather gets colder, it’s important to take steps to properly cover and protect your fireplace during the winter months. An unused fireplace that isn’t properly sealed can allow cold air, dust, and even animals to enter your home. Covering your fireplace is an easy task that can save energy and prevent problems in your house. Here are some tips on the best ways to cover a fireplace in winter.

Why is it important to cover your fireplace in winter?

There are a few key reasons why you should make sure to cover your fireplace when it’s not in use during cold weather:

• Prevent heat loss – An open fireplace is essentially a giant hole in your wall allowing warm air to escape and cold air to enter, wasting energy and making your heating system work harder.
• Keep out drafts – Any cracks or openings around a fireplace can let in cold drafts, reducing your comfort level.
• Stop debris and dirt – An open flue is an invitation for birds, leaves, twigs, insects and other undesirables to enter your home.
• Reduce moisture issues – Sealing the fireplace prevents excess cold air from entering and creating condensation or moisture problems inside your chimney.
• Discourage animals – Animals like birds and raccoons sometimes try to nest in chimneys, which you don’t want in your home.
• Safety for pets and kids – An open fireplace can be a falling or burning hazard for small children and pets.

Taking the time to properly seal up your fireplace when not using it keeps your house more comfortable, saves energy, and prevents many potential problems.

What supplies do I need?

Covering up your fireplace is a simple project you can do with just a few supplies:

• Chimney plug or balloon – An inflatable chimney plug fits into your flue opening and seals it off. This is the most effective option.
• Chimney cap – A metal cap installs on top of your chimney to prevent water and pests from entering.
• Fireplace plug – A plug specially sized to fit inside your fireplace opening to block air flow.
• Insulation blanket – A fiberglass blanket custom-fit for your fireplace opening to seal it off.
• Plywood or particle board – You can also use a sheet of plywood, cut to size, to seal up your fireplace opening.
• Caulk or insulation – To seal any gaps or cracks left around your fireplace.

Make sure you have the proper supplies on hand before beginning your project. Shop at your local hardware store or order online. Your total cost will likely be under $100.

How do I measure my fireplace?

Before purchasing any fireplace plugs, caps, or blankets, you’ll need to measure your fireplace opening so you can get the properly sized cover:

1. Use a tape measure to measure the height and width of the fireplace opening at the front. Write down the dimensions.
2. Next, measure the depth of the opening from front to back. Include the measurement in your notes.
3. For a chimney plug, you’ll need the dimensions of your flue opening at the top of the chimney. You can eyeball this measurement if you can’t access the roof.
4. Have these measurements handy when shopping online or at the hardware store.

Follow these steps and you’ll get the right sized cover for a proper fit install. Having the correct measurements ensures there are no gaps for air leaks.

What’s the best way to seal the fireplace flue?

Sealing the flue, the opening at the top of the chimney, is the most critical step in completely covering your fireplace. Here are recommended options:

Chimney plug

A chimney balloon or plug fits right into the flue opening. Inflatable plugs are easy to install for a complete seal. Just insert and inflate until snug. This is the quickest and most effective chimney seal.

Chimney cap

A chimney cap is a metal covering installed on top of the chimney. While not an airtight seal, a chimney cap does prevent water intrusion and debris from falling down the flue. It’s an easy option to add protection.

Insulation blanket

For a tighter seal, fiberglass insulation blankets are available to fit into your flue opening. Fill any gaps around the edges with insulation or caulk.

Be sure to follow manufacturer instructions carefully for proper installation. Sealing the flue completely is key to insulating your fireplace most effectively.

How do I seal the fireplace opening?

Once the flue is sealed, you still need to cover the actual fireplace opening. Here are safe and effective options:

Custom plug

Plug inserts designed specifically for fireplace openings provide the tightest seal. Match the plug size to your opening measurements for the best fit. Fill any remaining gaps with caulk or insulation.

Plywood cutout

For a simple DIY option, take a piece of plywood or particle board and cut it to fit your fireplace opening size. Paint or stain it to match your decor. Prop it in place or attach with removable adhesive.

Insulation board or blanket

You can place rigid foam insulation boards or flexible fiberglass blankets cut to size behind your plywood cover for increased insulation and an airtight seal.

Be very careful not to permanently seal up the chimney flue, as you’ll need access for cleaning and inspection. The fireplace opening can be more permanently sealed until ready for use again.

What are some safety tips?

When tackling fireplace insulation, be sure to keep safety in mind:

• Read all manufacturer’s instructions fully before installing any products.
• Wear protective gloves and safety goggles for your hands and eyes.
• Have another person help you with any heavy or unwieldy materials.
• Use a sturdy ladder if accessing the roof, never stand on the chimney.
• Seal chimney flues lightly enough to remove plugs or caps if needed.
• Make sure your smoke and carbon monoxide detectors work properly.
• Keep all flammable materials away from the fireplace.

Following basic safety precautions will help the project go smoothly and prevent any injuries or accidents.

What materials work best to insulate a fireplace?

Certain materials are more effective than others when insulating a fireplace:

Fiberglass

Fiberglass, in batt or blanket form, is fire-resistant and provides excellent insulation. Use it to seal openings and gaps.

Expanding foam sealant

Applying expanding foam around the fireplace opening fills cracks and crevices thoroughly to block drafts.

Mortar

Plugging up unused flue openings in older fireplaces with mortar or cement stops air leakage through the chimney.

Caulk

A fire-rated caulk makes a great adhesive when installing covers. It remains flexible to seal any cracks.

Rock wool

Safe to use around chimneys, rock wool insulation placed behind covers hinders heat transfer.

Combining these common insulating materials creates an effective fireplace seal for maximum efficiency and comfort.

What are some alternative options besides sealing it?

If permanently sealing your fireplace doesn’t work for your situation, here are a few alternative options to consider:

Chimney balloons

Rather than completely capping the flue, use an inflatable chimney balloon inside. This seals the space when not in use but is removable.

Glass doors

Installing fitted glass doors across the front fireplace opening allows you to enjoy the ambiance while sealing in heat.

Humidifier

Running a humidifier can offset the dry air that enters through the flue and circulate moisture through your home.

Plexiglass panel

For a transparent barrier, attach a plexiglass panel painted black to reflect heat. Just remove it before building a fire.

Wood burning inserts

Wood-burning inserts incorporate a fireplace inside your existing space with better sealing capabilities.

With some creativity, you can find the best option to make your unused fireplace more efficient for the cold months.

Should I hire a professional for fireplace insulation?

You don’t necessarily need to hire a professional for basic fireplace insulation, but it’s a good idea for certain situations:

• If you have a very large, elaborate, or complex fireplace design.
• For installing chimney caps on tall hard-to-reach roofs.
• If your flue needs extensive repairs or re-sealing.
• For precarious installation areas like crowded attics.
• If you need custom-measured and fabricated materials.
• For older fireplaces with hazardous materials like asbestos.

Professional chimney specialists and contractors have the skills, tools, and experience to handle tricky fireplace sealing jobs safely. They can also properly inspect and clean the chimney.

For standard, accessible fireplaces in good repair, DIY insulation is often sufficient. Assess your specific situation to decide if pro help is advisable.

How much does it cost to insulate a fireplace?

Insulating a standard masonry fireplace to cover the opening and flue can cost anywhere from $50 to $500, depending on the products and method used:

Insulation Method	Estimated Cost
Fiberglass plug, batts, and caulk	$50 – $150
Chimney plug or cap	$100 – $250
Custom plugs or covers	$200 – $400
Professional installation	$300 – $500

Basic insulation batts, caulking, and polyurethane expanding foam can cost as little as $50. A professional installation with custom chimney caps and metal covers could run $500 or more.

Factor in the size and condition of your fireplace, accessibility, and your DIY skills. With the right materials and safety precautions, you can insulate your fireplace affordably.

How does fireplace insulation compare to other methods?

Insulating your fireplace is generally more effective and affordable than other options:

Plexiglass panel

Plexiglass is inexpensive but not very insulating. Cold still penetrates through the plastic.

Glass doors

Attractive but expensive. Glass doors cost over $500 but don’t seal as tightly as other materials.

Wood stove insert

Inserts are efficient but require a significant installation investment of $1,500 or more.

Plug and insulation

A simple plug and insulation batt or caulk costs little and seals up the fireplace nicely.

For a quick, cheap solution that makes a big difference in efficiency, insulating the fireplace is your best bet.

Conclusion

Covering up your fireplace during cold weather is easy to do, saves energy, and provides comfort and protection. Start by measuring your fireplace opening while noting the chimney flue size. Purchase supplies like chimney plugs or caps, custom fit plugs, and insulation batts or expandable spray foam. Safety comes first, so work carefully on a ladder and follow product instructions. Sealing the chimney flue and fireplace opening completely blocks drafts. Alternative options like glass doors or chimney balloons might work if you need accessibility. Inspect for leaks around the edges and caulk or use insulation to seal any remaining gaps. With the right preparation and supplies, you can winterize your fireplace inexpensively.