Smokestack Maintenance and Smokestack Repair:
The second law of thermodynamics developed through the fundamental work of Carnot, Clausius, and Kelvin states that every system left to itself changes in such a way as to approach a definite final state of rest.
For structural contractors, this law is never quite so evident as when it comes to industrial chimneys.
There are few structures which encounter more adverse conditions: conditions such as winds that rock a chimney in every direction, acid that can eat through concrete, wide variations of temperature, and sometimes problems from gases or lightning. In order to preserve industrial chimneys effectively, they must be maintained regularly, being monitored closely and carefully by an experienced industrial smokestack contractor or a commercial chimney contractor.
Smokestack Repair Company Work
At Continental Chimney we believe the greatest way to advertise is through quality workmanship enduring the test of time. At Continental Chimney we employ engineers skilled specifically in industrial chimney construction, steel smokestack construction, smokestack maintenance, and smokestack repair.
Industrial Chimney Repair Challenges 2
Water damage open joints
Bellow in chimney wall
due to lack of
Smokestack Maintenance at the SS Administration Phila, Pa
Industrial Chimney Repair at the SS building Phila, PA
Social Security Administration Building. Confined space repair patching of two 130′ X 2′ steel chimney columns at various heights inside the flue pipe.
American Concrete Institute
The History of Smokestack Maintenance
The Bricks: Since the beginning of the industrial revolution, chimneys have been built from bricks to heights ranging from 50 – 250 feet. They have been designed to service numerous types of facilities. Common brick was used for chimneys for thousands of years in factory chimneys, later perforated radial brick was invented in Europe by Alphons Custodis in 1869. Radial brick smokestacks were more capable and allowed chimneys to be built taller, revolutionizing the industry. These radial bricks chimneys are extruded bricks and have a hollow cored interior. Sitting side by side they allow for a secure bond between the brickwork. Since the face of these bricks are larger, less work and fewer bricks are needed to build a smokestack. On the other hand, the common brick chimney is heavier, takes up more space, and takes more time to build, repair, and dismantle. In the late 1800s, the radial brick chimney started replacing the common brick chimney. At that same time the industrial concrete stack was more expensive to build, so brick was the premier choice being sold by engineers and contractors. Later on, the concrete chimney would go on to replace the brick chimney where they would be built taller than 200 feet. After 1970 brick construction declined due to higher costs. In the 1950’s there were 12 manufacturing companies that produced radial bricks, today Continental Chimney is the only manufacturer of these radial bricks. Our bricks are made specifically for repair jobs on industrial stacks and chimneys.
Heat: In order to understand how to repair smokestacks, and the problems facing owners of radial brick chimneys, it is necessary to understand the history and how they are now being used today. Burning coal or oil produces sulfuric acid present in the flue gas which in turn gets absorbed into the walls of the chimney. However, brick chimneys are better able to handle the drier gas at a temperature of around 300º F, and sometimes as high as 1500º F. In the beginning, radial brick chimneys were built by the industrial chimney company without a full chimney liner or no liner at all. These liners would be made of bricks and of the same mortar as was used in the rest of the chimney. Later on, chimneys would have full liners if the operating temperature would be over 600º F. However, these higher temperature chimneys were insulated with asbestos, and today present a problem for the smokestack demolition company and smokestack abatement company. By 1960 refineries were using refinery smokestack contractors to build refectory lined steel smokestacks chimneys, and apartment commercial chimney company builders started the installation of refractory lined stainless steel industrial chimneys at the same time.
Natural Gas: Today the choice is for boilers to use natural gas, which has a higher water content, which in turn causes masonry to deteriorate at a faster rate. Steel chimneys also have signification problems with the higher water content. When flue gas temperatures fall below 350º F the water content in the smoke mixes with the acid in the fuel which does not always make it up and out the chimney. The acids then more readily form inside the column of the chimney in a gas condensation. Portland cement and partially lime does not do well in an acidic environment. Today maintenance includes the use of mortars in these joints with an acid-resistant gunite or another substitute that will work better than mortar.
Incinerators: Another burden the radial brick chimney is faced with are gases from incineration used to burn hazardous waste. Rather than erect a new or separate stack for incineration, it is often considered less expensive to route the incinerator breaching to the existing industrial boiler chimney. Incinerating plastic produces high concentrations of hydrochloric acid, and the result is that these acids end up in mortar chimney joints.
Refineries: Refineries sometimes use their refinery chimney to also vent gasses which at times exceed the intended operating temperatures of the chimney. Results in the annual refinery smokestack inspection will then show that the refinery chimney has significant damage and repair work that needs to go out to bid. The refinery chimney might need to be demolished in some cases by a refinery smokestack company. If they do not have a history with refinery smokestack demolitions the cause for the demolition may be unknown.
Conclusion: What is out of sight is often out of mind, and ironically more often than not the commercial smokestack and what is needed for maintenance goes on in operation neglected. Chimneys constructed of radial brick and steel and even concrete, require regular maintenance and repair to remain operational to reach their maximum intended lifespan.
Information About Industrial Chimney Maintenance, Industrial Chimney Repair
Paint: Some smokestack companies will sell work to paint brick smokestacks and also paint concrete smokestacks to help lower maintenance costs or else for advertisement reasons. However, when an industrial brick smokestack is painted water can get trapped behind the bricks and cause damage if the paint coating is not carefully inspected every few years. Brick smokestacks should never be painted. Concrete can be painted with less concerns, however once a coating is applied to a smokestack it needs to be maintained, otherwise it can cause more harm than good.
Weather: Like any exposed structure, chimneys deteriorate over time, especially here in the colder climates, where there can be greater fluctuations in temperatures. When water can get into the mortar joints the brick column of the chimney can become soaked. After this freezing weather can cause large sections of brick faces to break away from the chimney. Sometimes down the column water can flow and accumulate in the lower sections cracking and slowly turning all the bricks to sand. On any typical day of the week there can be some kind of wind, and in an industrial chimney this means that it is always in motion. In strong winds there can be serious damage when if a stack is not properly maintained. We advise for some older chimneys that they be tied off with guy wire and rope to prevent them from incurring damage if there is a hurricane approaching.
Pointing: Regular pointing of the mortar joints by a reputable smokestack company, replacing cracked bricks that will prevent water from soaking into the chimney column, is of the first things that needs to be considered.
Banding: Steel banding is often done on factory chimneys to prevent or stop cracks from progressing by the industrial chimney contractor. Banding is also used to stop the column from bellowing out in smokestack walls when it is over a certain age, and there is a history of acid attack. However, for these bands to function properly they need to be made of heavy steal and bent on the ends around to the inside rather than over the band clamp around and out. Welding bands together on the chimney does not work as well as using band clamps because after so many years rust will break the band apart. This is because it can be difficult to properly weld under the band or match steel end to end when a band is being constructed on a chimney.
Lightning: Damage from lightning strikes is more prevalent on radial brick chimneys, and we believe this is because a lack in maintenance in brick chimneys leads to ledges and openings in the top of the brickwork allowing water to soak into the brick column. When lightning strikes, these arias become super-heated and there is an explosion, sometimes long cracks are formed in a lighting strike down a side of the chimney column. Often a broken down lead goes unrepaired which is the cause. Typically a concrete chimney does not have so many problems and sometimes the steel in the concrete may be tied into the ground. Nevertheless, older concrete chimneys also become soft and porous for water to set into. Frequent industrial chimney inspection and maintenance of LPS components by a smokestack company should be done on a regular basis.
Inspection recommendations: Binocular inspections should occur once a year. Full height interior and exterior hands on inspection should be done every three years. Smokestack inspection and maintenance should be implemented on a regular basis to avoid rapid deterioration, as well as doing a pressure wash every five years. After an inspection there should be a careful consideration for maintenance. Commercial chimney maintenance and industrial chimney maintenance sometimes have different concerns. Location plays a part in how and in what way a chimney can be restored. Depending on the location various industrial chimney repairs should or should not considered by a company and their smokestack contractor
Improper Inspections: The Youtube link below leads to an improper cement repair job which was followed by a improper inspection. We bid on this job, and as a favor to Concord Steam, NH we removed this old cement work so new cement would go all the way back to sound cement. In other words, having a good inspection is just as important as doing a good repair job.
Below are videos of some of the equipment we use in our shop and in the field.