(write a full hat for rea inspections only) (mock up complete tool list) (safety and PPE chapter- MSDS books- OSHA standards)
Your job as a chimney sweep comes with some very serious responsibilities. Failure to carry out these responsibilities can lead to heavy financial loss by the company, loss of company reputation, loss of repeat business, lawsuits and who knows, you may even be held criminally negligent (get with lawyers on this..). You actually could be responsible for a death if you do not do your job correctly. The bottom line is make sure you fill out the chimney inspection form fully and accurately. If there are areas marked “Unsatisfactory”, write clearly and completely what the outpoint is. The inspection form is actually a legal document that can be used against the company and/or you in a court of law. Make sure you inspect everything there is to inspect. We are dealing with fire (literally!) and customers’ safety. Most people will take you seriously when you expose a fire danger to them. Believe it or not, a few will not. When you sense that this is the case, then do not be afraid to scare them in order to get them to act. You don’t even care if they go with another company for a repair; YOU JUST WANT THEM TO ACT AND GET IT HANDLED!! Your motto is document-communicate. Document-communicate. Document-communicate. Make sure the documents get returned to the office for safekeeping.
The sweep’s job is to:
- Clean the chimney flue or liner thoroughly if needed.
- Clean the firebox of the chimney or woodstove thoroughly: The firebrick of the woodstove do not need to be removed unless they make up an overhead baffle in the stove.
Overhead baffle in a woodstove, made of fire brick.
- Ensure that the fireplace or woodstove is going to draft correctly after leaving the job.
- Ensure that any rain cap in place is clean of creosote that can reduce draw and/or catch fire. Build-up in chimneys Burning wood and fossil fuels in the absence of adequate airflow (such as in an enclosed furnace or stove), causes incomplete combustion of the oils in the wood, which are off-gassed as volatiles in the smoke. As the smoke rises through the chimney it cools,causing water, carbon, and volatiles to condense on the interior surfaces of the chimney flue. The black oily residue that builds up is referred to as creosote, which is similar in composition to the commercial products by the same name, but with a higher content of carbon black.
Over the course of a season creosote deposits can become several inches thick. This creates a compounding problem, because the creosote deposits reduce the draft (airflow through the chimney) which increases the probability that the wood fire is not getting enough air for complete combustion. Since creosote is highly combustible, a thick accumulation creates a fire hazard. If a hot fire is built in the stove or fireplace, and the air control left wide open, this may allow hot oxygen into the chimney where it comes in contact with the creosote which then ignites—causing a chimney fire. Chimney fires often spread to the main building because the chimney gets so hot that it ignites any combustible material in direct contact with it, such as wood. The fire can also spread to the main building from sparks emitting from the chimney and landing on combustible roof surfaces. In order to properly maintain chimneys and heaters that burn wood or carbon-based fuels, the creosote buildup must be removed. Chimney sweeps perform this service for a fee.
Between 2002 and 2004, 73% of heating fires and 27% of all residential fires in the United States were found to be caused by failure to clean out creosote buildup. Since 1990, creosote buildup has caused 75% fewer fires. This is partly due to the use of efficient wood-burning stoves that fully combust the carbon from fuel, and partly due to the use of Class A flues, insulated double wall stainless steel pipe.
- Ensuring that the overhead baffle in a woodstove is put back in place properly.
- Ensure that chimney flashing (or the cone flashing of a round, metal chimney) is keeping water out of the structure of the house.
Chimney “step flashing.”
Chimney “cone” flashing.
Examples of flashing that can leak and need repair:
Bent flashing. In a driving rainstorm water can get behind the flashing and run down the chimney into the house. This can stain walls and ruin ceilings.
This flashing was not even installed correctly. The flashing that is supposed to be tucked underneath the roofing shingles is not tucked!!
Good flashing.The corners are wrapped, the step flashing pieces overlap each other nicely. It could use a few screws to tighten it up. Step flashing pieces that barely overlap each other can be penetrated by rain. The step pieces should overlap at least 1”.
Storm collar missing caulking. Water can run down the chimney pipe and get into the structure and cause damage.
Intersections of the flashing are not caulked. They need to be caulked to prevent water penetration.
Good flashing job on an insulated chimney system that leads to a free-standing woodstove. Notice how well the storm collar is caulked. The cone flashing is tucked well under the roofing material and is flat against the material. There would be caulking on the 2 sides of the flashing, with the bottom edge left un-caulked. These sides were caulked after the photo was taken.
- Ensure that the hearth is intact and sufficient in size.
(the black slab in front of the fireplace opening is the hearth.)
Generally, the slab or brick need to extend 16” out and 12” out from each side. Larger dimensions are even better.
The firebox needs to be in good condition. Look for missing mortar joints and missing, loose or damaged firebrick inside of the firebox. Make sure that the firebox has not pulled away from the face of the fireplace.
Missing mortar between the firebrick.
To properly inspect a firebox, you have to stick your head inside of the firebox and look all around, particularly at the 4 vertical seams and all of the overhead area.
Many fireplaces have an ash dump door in them that ashes can be shoveled into.
The ashes end up in an empty cavity below the door. Open the door and shine your flashlight down it to see how full it is. Let the customer know how full it is. Before you leave the customer’s house, check for a cleanout door for the ash dump itself. This is the door where you remove the ash you have dumped. It will either be outside at the bottom of the chimney or it will be in the basement of the house. Make sure that the door is in good condition and is sealing tight. A missing door can cause a fire if hot coals are pushed into the ash dump and then spill out into the room below. If no clean-out door is present, hot coals can spill out into the room and make contact with combustibles, potentially starting a fire.
Clean-out door in good condition.
Check to see that a fireplace grate is in place and in good condition. This will help to protect the firebox floor. Woodstoves do not have fire grates, nor should they.
Fireplace and wood stove dampers
Make sure the damper in the fireplace opens and closes completely. It should move easily through its entire range-of-motion. A stiff damper can often be worked back and forth several times to loosen it up. Spraying its hinge pins and lever linkage with WD-40 often helps to free-up a damper. In the case where a damper has been replaced with a top-closing damper (a damper placed on top of a chimney,) make sure that it opens all of the way. Adjust the handle, if needed. Make sure the customer knows how to operate the damper correctly. In the case of a top-closing damper, if freezing temperatures are present, make sure that ice has not formed on top of the damper and is not preventing the damper from opening. Open fireplace dampers and top-closing dampers are designed to be either all of the way open or all of the way closed. They are not designed for adjustable settings.
Fireplace damper (open all the way)
Top-closing damper on top of chimney.
Dampers on woodstoves and woodstove fireplace inserts are adjustable and control the amount of combustion air that is fed to the fire. Increasing the amount of air intake will make the fire burn hotter and faster. Decreasing air intake does the opposite. Make sure the damper adjustment is moving its full range. If it seems that it is not, look for ash and debris to be blocking the outlet in the firebox. It may or may not be accessible. Always check for clogs in the air intake port. Vacuum out any ash or debris you may find.
Dampers on the doors that screw open and closed. This is an insert from the 1970s.
Make sure that the customer knows how to operate their dampers correctly; this is good customer service and professionalism. There are a couple different styles of top-closing dampers. The idea is that when the customer closes them they need to be closed all of the way. This prevents heat loss up the chimney when the fireplace is not in use. This is not a concern in the case of woodstoves.
Spark Screen and Doors
The screen needs to be in good condition and adequately cover the opening of the fireplace. If screens are beat up, do not close all the way, etc. then the customer needs to be told about it. It also needs to be written on the inspection form. Same goes for glass doors. Some glass doors are not designed to be used in the closed position while a fire is burning. The only way of truly knowing is by the manufacturer’s usage statement. We sell, install and recommend Pleasant Hearth glass fireplace doors. The are well-constructed, well-priced and look great. Customers can order them and put them in themselves if they wish. We get them off of Amazon.
Tools and Gloves
If a fireplace tool set is not seen, recommend to the customer that they purchase one. Amazon is a great place to get these items.
This line item in the inspection form refers to the bricks and the mortar joints between the bricks. The bricks should be securely bonded to each other. If the mortar has weakened or failed, there could be loose bricks that need to be re-laid. There may be the situation where the mortar joints have worn, cracked, are beginning to extend out of position, or are completely missing. Any unsatisfactory brickwork needs to be noted.
There are 3 degrees of creosote that can develop in a chimney:
First Degree Creosote Buildup
First degree creosote has a high percentage of soot and can be removed from a chimney effectively with a chimney brush. First degree creosote develops when there is a relatively good combustion of the wood and/or relatively high flue gas temperatures.
This describes an open fireplace. The burning wood had lots of air for the combustion process and the heat flies up the chimney. These are best conditions for a chimney.
Second Degree Creosote Buildup
Second degree creosote is a bit trickier. This creosote buildup is generally in shiny black flakes. Imagine dry, hard tar corn flakes, and in greater volume than first degree creosote. It’s not as easy to brush away, but still fairly removable. It would be difficult to describe all the situations where 2nd degree creosote develops, but suffice to say it will occur where the incoming air is restricted. This describes woodstoves and fireplaces with glass doors.
Third Degree Creosote Buildup
Third degree creosote buildup is the worst of them all. This occurs when the flue temperatures are low and/or combustion is incomplete. This is common when any of, or a combination of, these conditions exist:
- On woodstoves with the air controls turned way down
- Un-insulated chimneys (or any other reason the chimney is cold)
- When using unseasoned wood
- If the flue is oversized for the appliance
- When the house is tight and can’t draw sufficient combustion air
Third degree creosote looks like tar coating or running down the inside of the chimney. It is extremely concentrated fuel. It can get very thick as it hardens and is recoated over and over. An inch thick would be unusual, but it’s not unheard of.
And worse yet is third degree creosote that fills up “chimney fire fluff.” If creosote buildup catches fire in a chimney, maybe it burns away completely but more often it does not. More frequently the creosote partly boils, partly burns and leaves a dried out light-weight “sponge,” often more than 2” thick which is actually very easy to remove. But if it is not removed, new third degree creosote fills that sponge you can have well in excess of 100 pounds of creosote in a chimney.
The first chimney fire may not have damaged the house, but that next chimney fire will be fiercer than the first and exceptionally dangerous. The really tough part is that third degree creosote, in any form, is very hard to remove.
Third degree build-up in a chimney flue.
Clean chimney flue. Notice the brush marks.
Page left blank. Scroll down to next page.
|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.
As you relax in front of your fireplace or bask in the warmth of your wood stove, 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.
Dirty chimneys can cause chimney fires, which damage structures, destroy homes and injure or kill people.
Indications of a chimney fire have been described as creating:
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.
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 a black or brown residue that can be crusty and flaky…tar-like, drippy and sticky…or shiny and hardened. All forms are highly combustible. If it builds up in sufficient quantities – and the internal flue temperature is high enough – the result could be a chimney fire.
Conditions that encourage the buildup of creosote:
- restricted air supply
- unseasoned wood
- cooler than normal chimney temperatures
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.
The Effect of a Chimney Fire on Your Chimney
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.
Prefabricated, 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 prefabricated 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 prefabricated, 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
We are currently testing a product and procedure to remove third degree creosote. If successful, this hat will be updated with the procedure.
Here is a photo looking down the flue tiles inside of a chimney.
The flue tiles are made of terracotta material. Flue tiles are stacked one upon another inside of the chimney cavity as the chimney is being built up. They act as an extra layer of protection, kind of a chimney within a chimney. Prior to the code change that required installation of chimney flue tiles, the chimney was simply built up, and the inside of the flue parged with mortar. You will come across chimneys with and without flue tile linings.
Often times the chimney will not have a terracotta lining, but will have a terracotta flue tile cemented to the top of the chimney.
This is done so that chimney caps mass-produced in a factory can be purchased and used to keep rain and animals out. Notice that the smallest sized tile is on the left. The smaller tile usually indicates that that flue is for the furnace of the house. The larger tile in the center usually leads to the fireplace on the main floor. The larger tile on the right usually leads to a fireplace on a lower floor or in the basement of the house. The chimney in the photo above is a multi-flue chimney. There are 2 divider walls within the chimney. Each appliance has its own separate flue for exhaust to travel up.
Looking down a multi-flue chimney (no terracotta flue tile lining.) Notice the stainless steel liner inserted into the right side flue. This liner is running down to the furnace. The furnace flue is being “lined” with a liner system.
Flue tiles can be damaged by chimney fires, falling trees and freezing weather. Beware if you see a multi-flue chimney with a flue tile missing from the top of the oil flue, yet there are still flue tiles over the other flues. This could mean that the flue tile over the furnace flue was damaged and fell down into the flue. Furnace flues are usually of smaller dimensions , and a collapsed flue tile can clog them easily. Always investigate if this is the case. In the case of an oil fuel furnace, go to the furnace and check for chimney draw. Also, open the clean-out door at the bottom of the flue and look for broken pieces of flue tile. You can check for draw by opening the barometric damper flap of the exhaust pipe. Light a match and see if the flame is pulled into the pipe. This indicates chimney draw.