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What is Tuckpointing and Why is it Needed on Chimneys?

Posted on September 8, 2017 at 6:25 PM Comments comments (0)

What is Tuckpointing and Why is it Needed on Chimneys?

Erosion of Brick & Mortar

If you have a fireplace and chimney, as you probably know, you have a beautiful design feature which increases the value and appeal of your home and provides opportunities for enjoyable moments by a cozy fire. But did you know that all masonry chimneys need repair at some point? The mortar joints become damaged due to harsh weather conditions, particularly excessive amounts of water. Moisture can even damage rock masonry, when water gets in due to weakened mortar joints. “Tuckpointing” is a repair process which stops the destructive process and provides numerous benefits.

Is Tuckpointing Necessary?

While bricks on a chimney last about a century, mortar has a much shorter lifespan. Depending on how exposed the masonry is to excess water and other harsh conditions, mortar lasts about 25 years. It’s sometimes highly recommended that homeowners install a cricket, which is a compact diversion roof that prevents the chimney from being deluged in rainy weather. The layout of the roof and the position of the chimney affect how much or little water drainage contributes to erosion of the mortar joints.

When mortar joints become damaged, the most cost-effective action that a homeowner can take is to repair affected areas via tuckpointing. The alternative is to allow the mortar joints to deteriorate to the point that the chimney collapses, which makes a complete rebuild necessary–of course, the cost of a rebuild is far greater than the cost for repairs.

How is Tuckpointing Done?

The basic idea behind tuckpointing is that damaged mortar is removed, and it is replaced with fresh mortar. Tuckpointing a red brick chimney involves the following basic steps:

Grounding or routing out the old mortar at a uniform depth.

Filling in red mortar in the newly routed grooves.

Cutting thin strips down the middle of the red mortar, to form grooves.

Filling in the grooves with a mortar color which matches the original mortar on the outside of the structure.

Benefits of Tuckpointing

The appearance & stability of the chimney is seemingly brand new after tuckpointing has been completed.

Tuckpointing is really a crucial procedure, to preserve the life of a chimney. Some of the benefits of performing needed tuckpointing on chimneys follow:

  • Corrosion of the mortar joints is stopped.
  • Structural stability of the chimney is restored. Failing to repair mortar joints will result in a weak chimney structure which will eventually begin to lean or collapse.
  • Tuckpointing helps to prevent water from entering into the chimney system. If the mortar joints are not repaired, water will seep down the chimney and sometimes between the chimney and the flue lining. Moisture can do a serious amount of unseen damage, such as cause mold, mildew, and rotting wood. Moisture can also cause the ceiling and wallpaper around the chimney to become stained.
  • Tuckpointing is far more cost-effective than a complete tear-down and rebuild. The procedure allows you to avoid the expense of completely replacing the chimney structure.
  • Your chimney’s masonry materials are restored to their original condition.
  • The value of your home is improved when the masonry is in top condition.

Please call us to discuss your chimney needs.

How Your Chimney Really Works

Posted on August 5, 2017 at 4:30 PM

Here are some simple scientific fundamentals to explain how and why a chimney works - or maybe why it doesn't. This information is from Chimney Safety Institute of America.

Your House as a System

Even though you can't see it, the air in your house is in constant motion. In general, airflow tries to flow out of your house in the upper parts and replacement air tries to flow into your house in the lower parts of your house. Thinking of your house as a system makes it easy to understand the reasons for that airflow. Many changing factors, including: stack effect, wind loading, interior mechanical systems, and fuel-burning appliances such as furnaces, fireplaces, wood stoves and water heaters influence a home's airflow.


Homes built or renovated in the past 25 years are more airtight than older homes. This makes it much more difficult for replacement air to enter the home. As the saying goes, “hot air rises”, and so does the warm air in your home.


When the warm air rises to the upper areas of your home, it's called the stack effect. That trapped air forces its way out - even through very small openings such as recessed light fixtures and window frames. At the same time replacement air is trying to enter in the lower part of the building to make up for the escaping air.


Somewhere in your house, amid all this airflow, is the Neutral Pressure Plane (NPP). Above this theoretical plane, the air pressure is slightly greater than the outdoor air pressure and it tries to force its way out of the house. Below the plane, it is slightly negative and the house is trying to draw air in from the outside. The location of the NPP changes in response to changing conditions. The factors that affect airflow in the house also influence the level of the Neutral Pressure Plane.


Anytime a fireplace or fuel-fired heating appliance (except direct vent) is below the Neutral Pressure Plane, air will tend to flow into the house through the chimney or vent. A common example of this is found in homes with two fireplaces, one below the other. As the upper level fireplace uses air for combustion and chimney flow, it depressurizes that level slightly causing air to flow upwards from the lower level. Since the lower level fireplace is below the NPP, it draws air into the basement through the chimney. Unfortunately, since those two flues generally exit the chimney close to each other, the replacement air can contain some smoke from the fireplace above and it can pick up unpleasant chimney odors as it passes down the chimney flue.


Wind-loading is the effect on interior house pressures caused by the wind. When wind strikes a building, it creates high pressure on the side that it hits and low pressure on the downwind side. Any open windows or doors on the windward side will help to pressurize the house, increasing chimney draft. However, openings on the downwind (leeward) side will depressurize the house and increase the likeliness of backdrafting from chimneys or vents. Backdrafting is a reversal of the airflow in which the smoke is coming into the house instead of going up the chimney.


Interior mechanical devices such as clothes dryers, kitchen fans, bathroom fans, attic fans and central vacuums can also create depressurization by removing large volumes of air from the house. The result is often negative pressure in the area of a fireplace, woodstove, or other fuel-fired heating appliance making it difficult for natural draft chimneys to function as intended. Another common mechanical system that removes air from the house is a forced-air furnace. Many such systems are out-of-balance due to leaks in the ducts. Leaky supply ducts force air into

the attic or crawlspace. Leaky return ducts draw air from the basement or other areas they pass through.


Furnaces, water-heaters, fireplaces and woodstoves are examples of fuel-burning appliances that need large volumes of air for combustion. Unless they are specifically equipped to draw air in from outside the house, such as direct vent appliances, operating them can reduce the inside air pressure. There are a variety of mechanical devices on the market that help provide the necessary replacement air to balance the air pressure needs of your house system.


Draft and Flow

Although most people don't realize it, the air moving up your chimney works under the same set of physical principles as water flowing in a hose or pipe. When a fireplace chimney is full of hot air, it actually pulls air through the firebox. This pulling effect is called draft and it corresponds to the amount of pressure in a water hose - the only difference is that the air pressure is negative and the water pressure is positive (think of using a straw to drink with instead of to blow bubbles). Thus, chimneys are negative pressure systems.


Increasing the draft in your chimney is like opening the faucet wider on the hose. The simplest way to increase the draft in your chimney is to burn the fire hotter - hotter air is lighter, so it has more pull. Another way to get more draft is to increase the height of your chimney - except when the chimney is already so tall that frictional forces negate the effect of the extra height. ​ Given the same amount of pressure, a larger pipe can carry a greater volume of water than a smaller one. The same is true for chimneys - with the same amount of draft (pressure) a larger flue will exhaust more smoke from your fireplace than a smaller one. Similar to how a water hose can be kinked or plugged, the airflow in your chimney can have a restriction that slows down the smoke flowing up the chimney.


​Poor flow in a chimney can result from: excessive creosote deposits, closed or plugged dampers, improper construction, structural damage or even a dirty chimney cap. In fact, having a plugged-up chimney cap at the end of your chimney is like having a closed nozzle at the end of a hose - preventing airflow through the chimney. Our company can check your chimney and recommend any corrective action needed for proper draft and flow. ​

Gas Fireplaces

Posted on August 2, 2017 at 4:00 PM

Should a gas fireplace be inspected yearly?


Without a doubt! Although gas is generally a clean burning fuel, the chimney can become non-functional from bird nests or other debris blocking the flue. Modern furnaces can also cause many problems with the average flues intended to vent the older generation of furnaces. 

Smoke from other chimney

Posted on July 29, 2017 at 3:55 PM

If you build a fire in your upstairs fireplace, and get smoke from the basement fireplace the following is why:


This has become quite a common problem in modern air tight houses where weather-proofing has sealed up the usual air infiltration routes. The fireplace in use exhausts household air until a negative pressure situation exists. If the house is fairly tight, the simplest route for makeup air to enter the structure is often the unused fireplace chimney. As air is drawn down this unused flue, it picks up smoke that is exiting nearby from the fireplace in use and delivers the smoke to the living area. The best solution is to provide makeup air to the house so the negative pressure problem no longer exists, thus eliminating not only the smoke problem, but also the potential for carbon monoxide to be drawn back down the furnace chimney. A secondary solution is to install a top mount damper on the fireplace that is used the least.


Smelly Fireplace

Posted on July 25, 2017 at 3:50 PM

If your fireplace stinks, especially in the summer, this is why and what you can do about it:


The smell is due to creosote deposits in the chimney, a natural byproduct of woodburning. The odor is usually worse in the summer when the humidity is high and the air conditioner is turned on. A good sweeping will help but usually won't solve the problem completely. There are commercial chimney deodorants that work pretty well, and many people have good results with baking soda or even kitty litter set in the fireplace. The real problem is the air being drawn down the chimney, a symptom of overall pressure problems in the house. Some make-up air should be introduced somewhere else in the house. A tight sealing, top mounted damper will also reduce this air flow coming down the chimney.

The Facts About Chimney Fire

Posted on December 28, 2016 at 12:10 AM Comments comments (0)

Your chimney–and the flue that lines it adds architectural interest to your home, but its’ real function is to carry dangerous flue gases from your fireplace, wood stove or furnace safely out of your home. A chimney helps your household air stay breathable… just as your windows and your bathroom, attic and kitchen vents do. Unlike those other exhaust points in your home, however, fireplace and wood stove chimneys need a special kind of care. As you snuggle in front of a cozy fire or bask in the warmth of your wood stove, you are taking part in a ritual of comfort and enjoyment handed down through the centuries. The last thing you are likely to be thinking about is the condition of your chimney. However, if you don’t give some thought to it before you light those winter fires, your enjoyment may be very short-lived. Why? Dirty chimneys can cause chimney fires, which damage structures, destroy homes and injure or kill people.

No One Welcomes a Chimney Fire

A chimney fire in action can be impressive. Indications of a chimney fire have been described as creating:  loud cracking and popping noise; a lot of dense smoke; and an intense, hot smell

​Chimney fires can burn explosively – noisy and dramatic enough to be detected by neighbors or people passing by. Flames or dense smoke may shoot from the top of the chimney. Homeowners report being startled by a low rumbling sound that reminds them of a freight train or a low flying airplane. However, those are only the chimney fires you know about.


The Majority of Chimney Fires Go Undetected

​Slow-burning chimney fires don’t get enough air or have fuel to be dramatic or visible and they often go undetected until a later chimney inspection, but, the temperatures they reach are very high and can cause as much damage to the chimney structure – and nearby combustible parts of the house – as their more spectacular cousins.

The best way to prevent a chimney fire is to have an annual inspection. With proper chimney system care, chimney fires are entirely preventable. ​

Creosote & Chimney Fires: What You Must Know

Fireplaces and wood stoves are designed to safely contain wood-fuel fires, while providing heat for a home. The chimneys that serve them have the job of expelling the by-products of combustion – the substances produced when wood burns. These include smoke, water vapor, gases, unburned wood particles, hydrocarbon, tar fog and assorted minerals. As these substances exit the fireplace or wood stove, and flow up into the relatively cooler chimney, condensation occurs. The resulting residue that sticks to the inner walls of the chimney is called creosote.


Creosote is black or brown in appearance. It can be crusty and flaky…tar-like, drippy and sticky…or shiny and hardened. Often, all forms will occur in one chimney system. Whatever form it takes, creosote is highly combustible. If it builds up in sufficient quantities – and the internal flue temperature is high enough – the result could be a chimney fire. Certain conditions encourage the buildup of creosote. Restricted air supply, unseasoned wood and, cooler than normal chimney temperatures are all factors that can accelerate the buildup of creosote on chimney flue walls. Air supply may be restricted by closing the glass doors, by failing to open the damper wide enough, and the lack of sufficient make-up air to move heated smoke up the chimney rapidly (the longer the smoke’s “residence time” in the flue, the more likely is it that creosote will form). A wood stove’s air supply can be limited by closing down the stove damper or air inlets too soon or too much. Burning unseasoned wood – because so much energy is used initially just to drive off the water trapped in the cells of the logs– keeps the resulting smoke cooler, than if seasoned wood is used. In the case of wood stoves, overloading the firebox with wood in an attempt to get a longer burn time also contributes to creosote buildup.


How Chimney Fires Damage Chimneys


Masonry Chimneys

When a chimney fire occurs in a masonry chimney – whether the flue is an older, unlined type or tile lined to meet current safety codes – the high temperatures at which they burn (around 2000°F) can “melt mortar, crack tiles, cause liners to collapse and damage the outer masonry material”. Most often, thermal shock occurs and tiles crack and mortar is displaced, which provides a pathway for flames to reach the combustible wood frame of the house. This event is extremely dangerous, call 911 immediately.


Pre-fabricated, factory-built, metal chimneys

To be installed in most jurisdictions in the United States, factory built, metal chimneys that are designed to vent wood burning stoves or pre-fabricated metal fireplaces must pass special tests. Most tests require the chimney to withstand flue temperatures up to 2100°F – without sustaining damage. Under chimney fire conditions, damage to these systems still may occur. When pre-fabricated, factory-built metal chimneys are damaged by a chimney fire, they should no longer be used and must be replaced.


Special Effects on Wood Stoves

Wood stoves are made to contain hot fires. The connector pipes that run from the stove to the chimney are another matter. They cannot withstand the high temperatures produced during a chimney fire and can warp, buckle and even separate from the vibrations created by air turbulence during a fire. If damaged by a chimney fire, they must be replaced.


Nine Signs that You’ve Had a Chimney Fire

Since a chimney, damaged by a chimney fire, can endanger a home and its’ occupants and a chimney fire can occur without anyone being aware of them it’s important to have your chimney regularly inspected. Here are the signs that a professional chimney sweep looks for:

“Puffy” or “honey combed” creosote

Warped metal of the damper, metal smoke chamber connector pipe or factory-built metal chimney

Cracked or collapsed flue tiles, or tiles with large chunks missing

Discolored and/or distorted rain cap

Heat-damaged TV antenna attached to the chimney

Creosote flakes and pieces found on the roof or ground

Roofing material damaged from hot creosote

Cracks in exterior masonry

Evidence of smoke escaping through mortar joints of masonry or tile liners


If you think a chimney fire has occurred, call a us for a professional evaluation. If your suspicions are confirmed, we will be able to make recommendations about how to bring the system back into compliance with safety standards. Depending on the situation, you might need a few flue tiles replaced, a new liner system installed or an entire chimney rebuilt. Each situation is unique and will dictate its own solution.

- Chimney Safety Institute of America



Posted on February 5, 2016 at 10:20 PM Comments comments (0)


By Todd Woofenden



A product of incomplete combustion: deposits of unburned, flammable tar vapors from wood smoke. Sometimes it is crusty or flaky in texture, but often sticky or hard, like slag. Creosote deposits are often hard to remove from chimneys, and pose a serious fire hazard.


One of the great misunderstandings in the world of woodstoves is how creosote fits into the picture. Contrary to popular belief, creosote is not an inevitable product of wood burning. Creosote forms when wood is burned incompletely, and is an indication of improper use, poor installation, or a poor wood stove design.


It is also extremely flammable, and is responsible for many chimney-related structural house fires each year.


The long and the short of it... If you find a buildup of creosote in your stove pipe or chimney, have the chimney cleaned right away, and determine what's causing it. There are four basic possibilities:


Operating the stove at a too-low burn rate

Especially in airtight stoves, if you damper the stove way down, for a long, low burn, you will create a smoky fire that emits lots of unburned tar vapors into the venting system. Since the temperature of the flue gasses will already be relatively low, these vapors will be particularly likely condense inside the pipe or chimney flue.


The solution is to keep the fire burning at a moderately-active rate. Go outside and check the flue. If lots of smoke is billowing from the chimney, you are burning it too low. Yes, this means you can't get as long a burn time from a load of wood, (unless you upgrade to a new, EPA-certified stove, which is designed to burn cleanly at a much lower burn rate) but you will actually get more heat from the same amount of wood, since creosote represents unburned fuel. You will also do your chimney and our environment a favor.


Using the wrong type of fuel

Burning green, wet, or excessively dry wood can cause creosote buildup.


Oversized flue or improper connection

If the chimney isn't quickly drawing the combustion products to the outdoors, due to an oversized flue, an excessively-long stove pipe, or too many elbows in the stove pipe – all of which tend to increase the amount of time the smoke stays in the venting system – then the smoke will tend to condense in the flue, forming creosote.


And if your stove pipe is over eight feet long, or contains more than two elbows, consider re- installing the stove for a shorter run with fewer elbows.


Poor woodstove design

Before the new EPA-certified stoves became available, "air- tight" wood stoves were considered the best type. Airflow into an airtight stove can be closely controlled, in some cases to the point that the user can literally put out the fire by closing the air controls.


In essence, the problem with air- tight stoves is that, while they offer the convenience of a long, low burn, they are not designed to burn the fuel efficiently during periods of low burn. Lots of fuel is wasted in the form of smoke, which condenses in the stove pipe and chimney as creosote.


The solution is the same as for Operating the stove at a too-low burn rate, above, although many older woodstove designs create a smoky burn no matter how you operate the stove.

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Posted on January 20, 2016 at 9:00 PM Comments comments (0)

Winchester Star article detailing contributions to Road to Recovery and Brett's family as a tribute to Brett David Muhleman's life.


Posted on December 11, 2015 at 11:55 PM Comments comments (0)

Not only will it keep out critters and leaves, but it will protect a masonry chimney from the devastating effects of the weather


An open chimney is an invitation to trouble, and sometimes to disaster… Any experienced chimney sweep can tell you why:


Rain Damage


Rain coming down an open flue mixes with soot or creosote, causing unpleasant odors and deterioration of flue walls. It can run down into the stovepipe, stove, fireplace insert or furnace, where it can cause rust damage. It can also rust out a fireplace damper. Rain plus coal soot from sulfuric acid, which is particularly destructive.


Even in a clean chimney, rain can damage flue walls and the smoke shelf in the area down behind. Moisture getting into cracks and Keep raccoons out of your chimney with a flue capmortar joints freezes and expands, making the cracks larger.


Unwanted guests


All sorts of pesky critters will crawl, slither or fly down an open flue. Chimney sweeps have been called out to evict (among other things) squirrels, cats, raccoons, ducks, snakes, barn owls and even a goose.


Baby raccoons are cute, but that big wild mama trying to protect them can be ferocious and rabid. Raccoon feces often contain the eggs of a roundworm parasite, bayliscaris procyonis, which can be lethal to humans.


Birds and their highly flammable nests are another common problem. The nests can block a flue or even fuel a chimney fire. An Ohio sweep removed a dozen dead birds from a blocked gas flue one cold winter’s night. The family had shut down the furnace because their homes carbon monoxide alarm had sounded.


A flue cap and screen will keep out leaves, critters and rain. It can prevent flaming balls of creosote from spewing out onto your roof if there is a chimney fire. A cap can also prevent the occasional downdraft. 


Prefabricated metal chimneys come with their own cap. For masonry chimneys, a variety of cap styles, sizes and prices are available to cover everything from a single flue to an entire multi-flue chimney.  They should be mounted securely, but not permanently, as they need to be removed when the flue is inspected and swept.


Installing a cap is a task best left to a chimney sweep, who is adept at using ladders and crawling about on roofs. Ask McKay Chimney Specialists, your chimney sweep, to show you the types of chimney caps that are appropriate for your chimney.


The National Fire Protection Association (NFPA) recommends annual inspection of flues serving gas, oil, and wood fueled heating systems.


When you call your chimney sweep about installing a cap, it makes perfect sense to go ahead and schedule an inspection of all your flues, fireplaces and heating stoves.


A little professional and preventive maintenance, preferably in the spring of the year, can go along way toward keeping your family safe and heading off the possibility of extensive (and expensive!) chimney repairs later on.


Posted on December 6, 2015 at 11:35 PM Comments comments (0)

Many homeowners wonder why a chimney is swept. Chimneys are swept to remove residues in the chimney which can block the flue and prevent proper drafting, and to remove flammable deposits which can cause a chimney fire.

All types of appliances which burn fuel and vent to the outdoors should be inspected annually and swept when needed such as:

-Chimneys that need annual inspection -Fireplaces that burn wood or gas -Chimneys serving wood stoves -Water heater flues & furnace flues -Vented gas hearth products: gas fireplaces, gas freestanding stoves, gas logs & gas inserts 


Wood smoke occurs because not all the chemicals in wood can be burned by your fireplace or wood stove. Smoke contains tiny, unburned but flammable solid particles which adhere to the walls of your chimney which are called creosote. As these deposits accumulate, a stray spark from your fire can ignite them causing a chimney fire.

Chimneys and connector pipes (such as the black pipe connecting a wood stove to the chimney) are designed as a passageway for smoke which passes through at relatively low temperatures; they are not built to withstand chimney fires, which can burn in excess of 2000 degrees. A chimney fire can destroy the mortar in a masonry chimney which can cause a chimney to collapse or allow the fire to spread to the framing members of your home. Sometimes a first chimney fire will "only" crack the flue tile liners. This situation is dangerous because a subsequent chimney fire now has an easy pathway to the walls of your house, allowing for massively destructive and dangerous house fires. When you have been advised that your flue tiles are cracked, it is time to take action and have the chimney repaired! 


Furnaces that use oil or gas also produce dangerous byproducts. First, the fumes that are being vented are generally more dangerous than wood smoke because they contain higher levels of carbon monoxide than wood smoke. Leaky connector pipes, improper flue sizing and other chimney problems such as cracked flue tiles, oversized flues or undersized flues and structural defects or deterioration can all lead to fumes entering your home. Carbon monoxide cannot be seen and cannot be detected by the human nose.

Visible soot in the house is one indication of a problem with your furnace and it's venting system. Visible soot means you need to call your furnace repair company, but also your chimney sweep! Your chimney exists to carry fumes and soot away from the living space, so even a faulty furnace should send soot up the chimney. Sooty walls may indicate a problem with the furnace, but this ALWAYS indicates a problem with the venting!

Oil soot is particularly nasty to deal with. It is harder to remove and we use specialized equipment to deal with it. Soot from gas furnaces and water heaters is less likely, but an annual inspection can help identify problems and correct them before a small problem becomes hazardous.

 Annual cleaning and inspections are very important to the safe and efficient operation of your home's central heating system. The chimney sweeping process averages one to two hours.