Why Does My Fireplace Smell in the Summer? Causes & Solutions

There’s nothing better than the smell of a wood-burning fire on a cold New England evening. But once winter ends and summer humidity arrives, you may notice something very different coming from your fireplace:  a strong, unpleasant odor.

If your fireplace smells sour, musty, smoky, or even like something rotting, you’re not alone. Over the summer, we often hear from homeowners who are surprised when their chimney suddenly starts to smell, even though it hasn't been used. Here’s why it happens, and what you can do about it.

The Triple Threat: Moisture, Humidity & Creosote Buildup

In most cases, summer chimney odors are caused by a combination of moisture, humidity, and creosote buildup inside the flue.

We all know what moisture and humidity are, but what is creosote?  It is the dark, tar-like residue left behind after burning wood. Over time, it coats the inside of your chimney and absorbs into porous masonry surfaces. During hot, humid weather, warm outside air moves down the chimney and mixes with moisture and acidic creosote deposits inside the flue. The result is a musky, smoky, or sour odor that can spread throughout your home.

The odor is often more noticeable:

• On humid or rainy days

• When the air conditioning is running

• At homes with tightly sealed windows and doors

• In lower-pressure areas, such as basements

>Did you know? When your air conditioning system is running, it can pull air down the chimney, bringing those odors directly into your living space.

Other Common Causes of Chimney Odors

Creosote is one of the most common culprits, but it’s not the only one. Summer chimney smells can also be caused by:

Animal Nests or Critters

Birds, squirrels, raccoons, and other animals often seek shelter inside uncapped chimneys during the spring and summer months. Nesting materials, droppings, or trapped animals can create extremely unpleasant odors.

Water Intrusion

Rainwater entering through a damaged crown or flashing, or a missing chimney cap, can soak into the chimney masonry, causing interior deterioration and musty odors.

Debris Buildup

Any leaves, twigs, soot, or other debris trapped inside the flue can retain moisture and contribute to odors.

Mold or Mildew

Excess moisture inside a chimney can sometimes lead to mold growth, especially in damp or poorly ventilated systems.

How to Reduce Summer Fireplace Odors

Schedule a Professional Chimney Cleaning & Inspection.

Because chimney odors can have multiple causes, the best first step is to schedule a professional chimney inspection. Our certified chimney technicians can quickly identify the source of the smell and recommend the proper solution before the problem worsens.

Install a Chimney Cap.

A properly installed chimney cap helps protect your chimney system by

• Keeping rainwater out

• Preventing animals and nesting debris from entering

• Reducing downdrafts

• Minimizing moisture-related odors

If your chimney does not currently have a cap, or if the existing cap is damaged, summer is the ideal time to install or replace one.

Repair Damaged Masonry.

Unfortunately, chimney masonry naturally absorbs water over time, which can lead to odors and structural damage, including cracked mortar joints, damaged bricks, and deteriorating crowns. Professional masonry repairs help seal vulnerable areas in your chimney and prevent water intrusion.

Waterproof Your Chimney.

Professional chimney waterproofing is one of the most effective ways to protect masonry from long-term moisture damage. It creates a breathable barrier that helps repel water while still allowing trapped moisture vapor to escape. When properly applied, chimney waterproofing can help protect your chimney for years.

Remove Fireplace Ashes.

Leaving ashes in the firebox throughout the off-season can contribute to lingering odors. At the end of the burning season, be sure to remove any remaining fireplace ashes, using a non-combustible container.

Close the Damper When Your Fireplace Isn’t in Use.

Closing the damper and glass fireplace doors when your system is not in use can help reduce the amount of humid outside air entering your home through the chimney. (Just remember to reopen the damper before starting your next fire.)

Why Summer is the Best Time for Chimney Service

Most homeowners wait until fall to schedule chimney cleanings and inspections. However, summer is actually one of the best times to service your chimney because:

• You will beat the “fall rush.”

• You can eliminate odors before they worsen.

• You can address any problems before the burning season.

• Your fireplace will be ready for when you need it most.

  
  

Chimney Cleaning, Inspection & Repair in NH and MA

Whether you’re dealing with unpleasant fireplace odors, water leaks, masonry damage, or overdue maintenance, the certified professionals at Admiralty Chimney can help. Summer is the perfect time to schedule your annual chimney cleaning and safety inspection so your system is clean, safe, and ready for fall. Call us at (603) 594-0499 or visit us online to schedule your appointment.

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Do you really need a chimney cap?

If your chimney doesn’t have a cap, you might be wondering if it’s really necessary. The short answer is yes. A chimney cap is a simple and effective way to protect your chimney and home. In New Hampshire, where we deal with heavy rain, snow, and freezing temperatures, that protection matters even more.

What is it and what does it do?

A chimney cap is a protective stainless steel covering installed at the top of your chimney. Typically, it includes a mesh screen and a solid top that allows smoke to escape while keeping unwanted elements (water, debris, critters) out.

Chimney Cap Benefits:

1. Preventing Water Damage

You may not know this, but water is one of the biggest threats to your chimney. If you don’t have a chimney cap, rain and snow can easily get inside it. Over time, this leads to moisture damage within the flue and masonry, and eventually to deterioration and costly repairs. A chimney cap acts like a roof for your chimney, helping keep it dry year-round.

2. Keeping Critters Out of Your Chimney

Birds, squirrels, raccoons, and other small animals often see a chimney as a safe place to nest, especially during cold weather. Without a cap, it’s only a matter of time before an uninvited guest moves in yours. Once inside, these critters can cause serious problems, including fire hazards and carbon monoxide buildup.

3. Blocking Debris

Small branches, twigs, leaves, and other debris can easily get into an open chimney, creating a fire hazard. By restricting airflow, debris buildup can also allow dangerous carbon monoxide gas to back up into your home. A chimney cap helps prevent debris buildup, reducing the risk of fire and improving ventilation.

4. Reducing Downdrafts

Brrr. Strong winds can push cold air down your chimney, creating drafts and decreasing energy efficiency. Installing a chimney cap helps reduce downdrafts, improving the performance of your fireplace or heating system.

5. Decreasing the Risk of a Roof Fire 

The mesh screen on a chimney cap can also act as a spark guard, preventing hot embers from escaping onto your roof. This added layer of protection can help reduce the risk of accidental roof or exterior fires.

What Happens If You Don’t Have a Chimney Cap?

It might not seem like a big deal at first, but not having a chimney cap can lead to serious (and expensive) problems over time, including water damage to your chimney liner, masonry, and even your home’s interior. And in New Hampshire’s climate, freeze-thaw cycles can exacerbate moisture damage, accelerating cracking and structural issues.

Small Investment. Big Benefits.

Compared to the cost of removing animal nests or repairing water damage, a chimney cap is a small investment that can extend your chimney’s lifespan and improve your home's overall comfort and safety.

Chimney Cap Installation in Southern NH & Northern MA

For over 20 years, Admiralty Chimney has been a trusted installer of chimney caps in southern New Hampshire and northern Massachusetts. Visit our website today to learn more about our services or schedule an appointment.

Protect Your Chimney From Water Damage

When most homeowners think about chimney damage, fire comes to mind. While a fire can cause devastating damage, there’s another culprit that quietly deteriorates chimneys before homeowners realize there is a problem:  water. 

At Admiralty Chimney, we’ve seen how quickly moisture can compromise a chimney’s structural integrity. For this reason, it’s important to know the common signs of water damage and how to prevent it. 

But first, let’s discuss WHY chimneys are so susceptible to water damage.

Chimneys are built with porous materials--like brick, mortar, and concrete--that absorb water.   During the winter months, absorbed water goes through repeated freeze-thaw cycles. Over time, it causes bricks to crack, mortar to crumble, and chimney liners to deteriorate .

Signs Your Chimney Has Water Damage

Water damage doesn’t always show up immediately, so be on the lookout for these common signs:

• Cracked or missing mortar joints

• Spalling bricks (flaking or popping surfaces)

• White staining (efflorescence) on the chimney exterior

• Rust on the damper or firebox

• Water stains on ceilings and walls

• Musty odors coming from the fireplace

• Leaning or tilting chimney structure

If you notice any of these signs, contact our chimney experts so we can take action before the problem worsens.

How Water Gets Into Your Chimney

Several factors allow water to enter your chimney system:

• Lack of a waterproofing sealant causes bricks to absorb water like a sponge.

• Condensation buildup occurs when a system is improperly vented.

• A damaged or missing chimney cap leaves the flue open to rain and snow.

• A Cracked crown or chimney top allows water to seep inside the chimney.

• Deteriorated mortar joints create pathways for moisture.

• Improperly sealed or installed flashing allows water to seep in.

Often, it’s not just one issue--but a combination of issues--that leads to significant chimney damage.

Long-Term Effects of Ignoring Water Damage

Water damage gets worse over time, leading to:

• Structural instability of the chimney

• Interior home damage, including ceilings and walls

• Mold and mildew growth

• Reduced heating efficiency

• Expensive rebuilds or full chimney replacement

Unfortunately, what starts as a small chimney crack can quickly become a major repair project.

How to Protect Your Chimney From Water Damage

Although water can cause devastating damage to your chimney, you can take measures to prevent it by:

1. Installing a chimney cap

A chimney cap helps keep rain, snow, debris, and small critters out of your flue.

2. Applying a waterproof sealant

Professional-grade waterproofing allows masonry to “breathe” while repelling water.

3. Repairing or replacing the chimney crown

The crown is your chimney’s first line of defense. Keeping it sealed and crack-free is essential.

4. Maintaining the chimney flashing

Ensure the metal flashing around your chimney base is tight and properly sealed to prevent roof leaks.

5. Scheduling an annual inspection

Routine chimney inspections catch small issues before they become expensive problems.

What to do if You Already Have Water Damage on Your Chimney:

If your chimney is already showing signs of water damage, contact us as soon as possible to schedule any needed repairs.  

Repair solutions vary according to the type of damage and may include:

• Tuckpointing (repairing mortar joints)

• Crown repair or rebuild

• Chimney cap installation

• Waterproofing treatment

• Flashing repair

• Partial or full rebuild in severe cases

Note: Summer is the best time to address chimney masonry repairs in New Hampshire, because the warmer, drier conditions allow the mortar and/or sealant to cure properly.  

Chimney Water Proofing & Water Damage Repair in Southern NH & Northern MA

Water may be the most common cause of chimney damage, but it’s also the most preventable. Contact us today to discuss our chimney waterproofing and water damage repair services.