Do you really need to waterproof your chimney?

When most homeowners think about chimney damage, a raging roof fire comes to mind. In reality, the greatest long-term threat to your chimney isn't fire; it's water.

Throughout the year, your chimney is exposed to water in many forms--from heavy spring rain to summer humidity to the repeating freeze-thaw cycles of winter. Over time, this moisture penetrates your chimney’s brick and mortar, causing masonry to crack, flake, weaken, and eventually fail. 

The bad news:  Left untreated, this damage can lead to costly repairs. 

The good news:  Waterproofing your chimney is a cost-effective way to prevent damage.

Why Water is so Damaging to Chimneys

Brick and mortar naturally absorb moisture. During colder months, that trapped water freezes and expands, creating pressure inside the masonry. As this process repeats year after year, it causes:

• Cracked bricks

• Deteriorating mortar joints

• Spalling (flaking or chipping masonry)

• Chimney crown damage

• Interior water leaks

• Mold and mildew growth

• Premature chimney deterioration

Because water damage develops over time, many homeowners don’t realize they have a masonry problem until significant and costly repairs are required. This is why scheduling a professional annual chimney inspection is so important.

Five Benefits of Professional Chimney Waterproofing

1. It Prevents Costly Water Damage.

A professional waterproofing treatment creates a breathable barrier that repels rain and snow before moisture can penetrate your chimney's masonry. Preventing water intrusion today can save thousands of dollars in future masonry repairs.

2. It Prevents Mold and Mildew Growth.

When water enters a damaged chimney, it can migrate into your home’s walls, ceilings, and framing. This excess moisture creates ideal conditions for mold and mildew growth, potentially affecting both your home and your indoor air quality.

3. It Extends the Life of Your Chimney.

Your chimney is built to last for decades-- but only if it's properly maintained. Waterproofing protects masonry from the constant cycle of moisture absorption and freeze-thaw damage, helping preserve the structural integrity of your chimney for years to come.

4. It Improves Energy Efficiency.

Damaged masonry allows heat to escape more easily while permitting unwanted moisture into your home. Keeping your chimney dry helps maintain its performance and contributes to a more energy-efficient home, particularly during the heating season.

5. It Preserves Your Home's Appearance.

A chimney is one of the most visible architectural features of your home. Cracked mortar, stained brick, and deteriorating masonry can negatively impact curb appeal. Waterproofing helps keep your chimney looking clean, well-maintained, and structurally sound.

Before Waterproofing Your Chimney…

Applying a waterproof coating over damaged masonry doesn't solve the underlying problem; it simply hides it. Before waterproofing your chimney, schedule a professional chimney inspection to identify and address any masonry damage, deteriorated mortar joints, cracked crowns, or other issues.

Can You Waterproof Your Chimney Yourself?

You could, but we don’t recommend it.  

Professional chimney waterproofing uses a specially formulated, vapor-permeable sealant that repels liquid water while allowing the masonry to release water vapor naturally. This is important because chimney masonry needs to "breathe." Products that trap moisture inside the brick can actually accelerate deterioration.

A professional waterproofing application also ensures your entire chimney is treated safely and evenly without exposing you to the hazards of working on a roof.

Is Chimney Waterproofing Worth The Investment?

Compared with rebuilding damaged masonry, replacing bricks, repairing crowns, or correcting water intrusion inside your home, chimney waterproofing is a relatively small investment that can significantly reduce future repair costs.

In New England, where chimneys are exposed to harsh winters and frequent freeze-thaw cycles, waterproofing is one of the most effective preventative maintenance services available.

Chimney Services in Southern New Hampshire & Northern Massachusetts

Admiralty Chimney provides professional chimney waterproofing, inspections, cleanings, and repairs throughout Southern New Hampshire and Northern Massachusetts. To connect with our CCP-certified team, call us at (603) 594-0400 or visit us online.

Signs Your Chimney Masonry Needs Repair

Your chimney masonry may be strong, but it certainly isn't indestructible. Over time, nature’s elements, including heavy rain, snow, ice, and humidity, make it expand, contract, and absorb moisture. This leads to cracks, loose bricks, deteriorating mortar joints, and even structural instability.

The good news? Most masonry problems can be repaired before they become major (and expensive) issues. Here's what every homeowner should know about chimney masonry repair:

What Does Chimney Masonry Repair Involve?

Chimney masonry repair involves restoring the brick, stone, mortar, or concrete components of your chimney to keep it safe, structurally sound, and protected from water damage.

Depending on the condition of your chimney, repairs may include:

• Replacing damaged or loose bricks

• Tuckpointing deteriorated mortar joints

• Repairing cracked crowns

• Rebuilding damaged chimney sections

• Replacing flashing around the chimney

• Waterproofing the masonry to help prevent future damage

Signs Your Chimney Needs Masonry Repair:

Cracked or Missing Mortar

Mortar joints naturally wear down over time. If you notice gaps, crumbling mortar, or missing sections between bricks, water can begin working its way into the chimney structure.

Loose, Cracked, or Spalling Bricks

Bricks that are cracking, flaking, or breaking apart (known as spalling) are usually a sign that moisture has entered the masonry and repeatedly frozen and thawed.

White Staining (Efflorescence)

White, chalky deposits on the outside of your chimney suggest that moisture has penetrated its masonry. The staining itself isn't harmful, but it usually suggests there is a water problem that needs to be addressed.

Water Leaks Around the Fireplace

Water stains on ceilings or walls near the chimney, damp fireplace walls, or musty odors often point to masonry or flashing problems.

Pieces of Brick or Mortar on the Ground

If you find fragments of brick or mortar around the base of your chimney, deterioration is already occurring and should be repaired promptly.

Leaning or Tilting

If your chimney is leaning or separating from your home, it is a serious structural concern that requires immediate professional attention.

More Than a Cosmetic Issue

A small crack in the masonry of a chimney is much more than a cosmetic issue. Even tiny openings allow water to penetrate your chimney’s masonry. Once moisture gets inside, every freeze-thaw cycle causes it to expand, making cracks larger and weakening your chimney over time.

Delaying masonry repairs can lead to:

• Extensive brick deterioration

• Interior water damage

• Damaged chimney liners

• Structural instability

• Costly chimney rebuilds

• Safety hazards for your home and family

Addressing minor masonry issues early is almost always far less expensive than waiting until major chimney reconstruction is required.

When Is the Best Time for Chimney Masonry Repair?

The ideal time to schedule chimney masonry work is during the spring, summer, or early fall.

These seasons typically provide:

• Warmer temperatures needed to allow mortar to cure properly

• Lower humidity for better masonry performance

• More predictable weather conditions

• Plenty of time to complete repairs before heating season begins

Scheduling repairs before fall also ensures your fireplace and chimney are ready for safe use when colder weather returns.

What if you find damage during the winter?

If masonry damage is discovered during the winter, temporary solutions may sometimes be used until permanent repairs can be completed under better weather conditions.

The Chimney Masonry Repair Process

Every chimney is different, but most repair projects follow a similar process.

1. Thoroughly Inspecting Your Chimney

We thoroughly inspect your chimney to identify masonry issues so we can address the underlying cause of the damage rather than simply repairing the symptoms.

2. Removing Damaged Materials

We carefully remove loose bricks, deteriorated mortar, cracked concrete, and any other damaged components—without disturbing the surrounding structure.

3. Repairing and Restoring 

Whenever possible, we color-match new mortar, replace damaged bricks, and repair and restore damaged bricks, crowns, flashing, and other components as needed. The goal is to blend repairs seamlessly with the existing chimney while restoring structural integrity.

4. Waterproofing (When Appropriate)

After repairs are complete, a professional-grade breathable waterproofing treatment may be applied to your chimney. This helps repel rainwater while still allowing trapped moisture inside the masonry to escape naturally.

5. Final Inspection

Before the project is complete, we inspect your chimney again to ensure repairs meet safety standards and it is ready for years of safe and reliable service.

Addressing Small Masonry Problems Before They Become Big Ones

It’s unlikely that any chimney masonry damage will improve on its own. Small cracks eventually become larger ones, minor water leaks turn into larger, costlier problems, and deteriorating mortar can compromise the stability of your entire chimney.

At Admiralty Chimney, our CSIA-certified chimney professionals provide detailed inspections, expert masonry repairs, and honest recommendations to help homeowners protect both their chimneys and their homes. Whether your chimney needs minor tuckpointing or more extensive masonry restoration, we'll help restore it safely and correctly the first time.

If you've noticed signs of chimney deterioration, or it's been a while since your last inspection, now is the time to schedule a professional evaluation so any needed repairs can be addressed before the burning season. Call us at (603) 594-0400 or visit us online to schedule an appointment.

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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