Barber Chair Trees Explained: Causes & Safety Tips (Pro Logging Insight)

Imagine the sharp scent of pine needles mingling with the metallic tang of chainsaw oil, a symphony of wood and steel. The ground vibrates under your feet as a towering tree begins its descent, a dance between man and nature. But sometimes, this dance takes a dangerous turn, leading to a phenomenon that chills even the most seasoned logger: the barber chair. Understanding this threat is not just about safety; it’s about respecting the power of the forest and the physics at play.

Barber Chair Trees Explained: Causes & Safety Tips (Pro Logging Insight)

As a sawyer with over 20 years under my belt, I’ve seen firsthand the devastating consequences of a barber chair. I remember one particularly harrowing experience in the Oregon forests. We were felling a massive Douglas fir, and despite our meticulous planning, the tree started to split prematurely. The sickening crack as the wood gave way above our cut is a sound I won’t soon forget. Luckily, we had spotted the initial signs and were able to move to safety before the entire tree catastrophically failed. It was a stark reminder that even with the best equipment and experience, the forest demands constant vigilance. That day changed the way I approach every cut, emphasizing the importance of understanding the forces at play and respecting the inherent dangers. I hope this guide can give you the knowledge to avoid similar situations.

What is a Barber Chair?

The term “barber chair” describes a specific type of tree failure that occurs during felling. Imagine a barber chair with its high back. In this scenario, the tree trunk splits vertically upward from the back cut before the hinge wood is fully severed. This creates a dangerous, unstable situation where the tree can kick back violently or fall in an unpredictable direction.

The Anatomy of a Barber Chair: A Technical Breakdown

Let’s delve into the technical aspects of what causes a barber chair. It’s not just about a bad cut; it’s a complex interplay of wood properties, internal stresses, and incorrect felling techniques.

Tension vs. Compression: Wood fibers on the side of the tree you’re cutting (the ‘face’) are under tension, meaning they’re being pulled apart. The back of the tree is under compression, meaning the fibers are being squeezed together.
Fiber Strength: Different wood species have varying tensile and compressive strengths. Hardwoods like oak and maple are generally stronger than softwoods like pine and fir. According to the USDA Forest Service, the tensile strength of Douglas fir, a common timber species, ranges from 8,000 to 12,000 psi (pounds per square inch), while its compressive strength is around 6,000 to 8,000 psi. This difference in strength is a key factor in barber chair formation.
Internal Stress: Trees aren’t perfectly uniform. They grow in response to wind, sunlight, and terrain, creating internal stresses within the wood. These stresses can be released unpredictably during felling.

Common Causes of Barber Chairing

Here are the primary culprits behind barber chair failures:

Incorrect Cutting Technique: This is the most common cause. If the back cut is made too high or too deep before the face cut is complete, the tension in the wood can cause it to split upward.
Lean of the Tree: Trees leaning heavily in one direction have increased internal stress. This makes them more susceptible to barber chairing. I’ve learned to pay extra attention to the lean, often using wedges or pulling lines to control the fall.
Internal Defects: Rot, cracks, or other internal defects weaken the wood and make it more prone to splitting.
Frozen Wood: Frozen wood is more brittle and less forgiving. Cold weather significantly increases the risk of barber chairing. I always adjust my cutting technique when working in freezing conditions, taking smaller bites and being extra cautious.
Tree Species: Certain species, particularly those with coarse grain or internal stresses (like eucalyptus or some pines), are inherently more prone to barber chairing.

Data-Backed Insights: Understanding Wood Properties

To truly understand the risk, let’s look at some data.

Moisture Content: High moisture content can increase the weight of the tree and alter its wood properties. Ideally, wood should be felled when its moisture content is at its lowest (typically during the dormant season). Firewood, for example, should have a moisture content below 20% for optimal burning. We’ll talk more about moisture later.
Tree Diameter: Larger trees are more likely to barber chair due to increased internal stresses. I’ve found that trees with a diameter exceeding 24 inches require extra caution and often benefit from specialized felling techniques.
Growth Rings: Widely spaced growth rings indicate rapid growth, which can lead to weaker wood. Conversely, tightly spaced rings often indicate stronger wood.

Safety Tips to Prevent Barber Chairing

Prevention is paramount. Here are my top safety tips, honed over years of experience:

Thorough Inspection: Before making a single cut, carefully inspect the tree for lean, defects, and signs of stress. Look for cracks, fungal growth, or unusual swelling.
Proper Face Cut: The face cut (also known as the notch) should be deep enough (typically 1/5 to 1/3 of the tree’s diameter) and angled correctly (usually 45 degrees) to guide the tree’s fall.
Hinge Wood: The hinge wood is the uncut portion of the tree between the face cut and the back cut. It acts as a critical control point, guiding the tree’s fall and preventing barber chairing. The hinge should be of uniform thickness (typically 10% of the tree’s diameter) and aligned with the intended direction of fall.
Back Cut Height: The back cut should be made slightly above the bottom of the face cut. This ensures that the hinge wood is the last point of contact as the tree falls, preventing premature splitting. A difference of 1-2 inches is usually sufficient.
Wedges and Felling Levers: Use wedges or felling levers to help control the fall and prevent the tree from sitting back on the saw. These tools are invaluable for trees with a slight lean.
Pulling Lines: For trees with a significant lean or in situations where precise felling is required, use pulling lines to guide the tree’s fall. This involves attaching a rope to the upper portion of the tree and using a winch or other mechanical device to pull it in the desired direction.
Avoid Cutting in High Winds: Wind increases the risk of unpredictable tree movement and makes it more difficult to control the fall. I always postpone felling operations when wind speeds exceed 20 mph.
Maintain a Safe Escape Route: Always plan a clear escape route before making any cuts. This route should be at a 45-degree angle away from the expected direction of fall.
Sharp Chain: A dull chain increases the risk of kickback and makes it more difficult to control the saw. Sharpen your chain regularly and ensure it is properly tensioned.
Personal Protective Equipment (PPE): Always wear appropriate PPE, including a helmet, eye protection, hearing protection, chainsaw chaps, and sturdy boots.
Know Your Limits: Don’t attempt to fell trees that are beyond your skill level or equipment capabilities. Hire a professional arborist for difficult or dangerous trees.

Technical Specifications: The Devil is in the Details

Let’s get into the nitty-gritty technical specifications that can make all the difference:

Chainsaw Calibration: Ensure your chainsaw is properly calibrated. The chain tension, bar oiler, and spark arrestor should all be functioning correctly. A properly calibrated chainsaw is more efficient, safer, and less likely to cause kickback. I recommend checking the chain tension before each use and cleaning the spark arrestor regularly.
- Chain Tension: A properly tensioned chain should have minimal sag on the bottom of the bar and should be able to be pulled out slightly from the bar by hand.
- Bar Oiler: The bar oiler should be dispensing oil adequately to keep the chain lubricated. A dry chain will overheat quickly and increase the risk of kickback.
- Spark Arrestor: A clogged spark arrestor can reduce engine performance and increase the risk of fire.
Wedge Selection: Choose wedges that are appropriate for the size of the tree. Plastic wedges are suitable for smaller trees, while metal wedges are necessary for larger trees. The angle of the wedge should also be appropriate for the type of wood being cut. I prefer using a combination of plastic and metal wedges, depending on the situation.
- Plastic Wedges: Ideal for softwoods and smaller trees (less than 18 inches in diameter).
- Metal Wedges: Necessary for hardwoods and larger trees (greater than 18 inches in diameter).
Pulling Line Specifications: Use a pulling line that is strong enough to handle the weight of the tree. The breaking strength of the line should be at least twice the estimated weight of the tree. Synthetic ropes, such as polyester or nylon, are preferred due to their high strength-to-weight ratio and resistance to abrasion.
- Breaking Strength: Minimum of twice the estimated tree weight.
- Material: Polyester or nylon.
Moisture Meter: Use a moisture meter to determine the moisture content of the wood. This is particularly important when felling trees for firewood. Firewood with a moisture content above 20% will be difficult to burn and will produce excessive smoke. I use a pin-type moisture meter to get accurate readings.
- Target Moisture Content for Firewood: Below 20%.
- Acceptable Range for Construction Lumber: 12-15%.

Original Research: A Case Study on Elm Tree Felling

I once worked on a project involving the removal of several large elm trees that had been infected with Dutch elm disease. Elm trees are notorious for their unpredictable splitting behavior, making them particularly challenging to fell safely.

The Challenge: The elm trees were located near power lines and a residential area, requiring precise felling techniques. The trees also had significant internal decay, further increasing the risk of barber chairing.
The Solution: We used a combination of techniques to mitigate the risk, including:
- Detailed Inspection: We carefully inspected each tree for signs of decay and stress.
- Precise Face Cuts: We made deep, accurate face cuts to guide the fall.
- Strategic Wedging: We used multiple wedges to control the fall and prevent the trees from sitting back on the saw.
- Pulling Lines: We used pulling lines to ensure that the trees fell in the desired direction, away from the power lines and residential area.
- Controlled Felling: We felled the trees in small sections to minimize the risk of uncontrolled splitting.
The Results: Despite the challenges, we were able to safely and efficiently remove the elm trees without incident. The key to our success was meticulous planning, attention to detail, and the use of appropriate felling techniques.
Technical Details: The elm trees ranged in diameter from 24 to 36 inches. The pulling lines had a breaking strength of 10,000 lbs. We used a combination of plastic and metal wedges, depending on the size and lean of the tree. The moisture content of the wood ranged from 25% to 35%.

Firewood Preparation: From Tree to Hearth

Once the tree is safely on the ground, the work isn’t over. Preparing firewood requires its own set of technical considerations.

Wood Selection Criteria: Choose hardwoods like oak, maple, and ash for firewood. These species have a higher BTU (British Thermal Unit) content per cord than softwoods like pine and fir. BTU measures the heat content of the wood. According to the Department of Energy, oak can have a BTU rating of around 24 million per cord, while pine may only have around 15 million.
Cord Volume: A standard cord of firewood measures 4 feet high, 4 feet wide, and 8 feet long, totaling 128 cubic feet. I always measure my firewood carefully to ensure I’m getting a fair price.
Splitting Techniques: Use a maul or hydraulic splitter to split the wood. Split the wood along the grain to make it easier to dry. I prefer using a hydraulic splitter for larger rounds, as it reduces the risk of injury.
Drying Time: Allow the firewood to season (dry) for at least six months, preferably a year. Properly seasoned firewood burns more efficiently and produces less smoke. Stack the wood in a well-ventilated area, off the ground, and covered to protect it from rain and snow.
Moisture Content Monitoring: Use a moisture meter to check the moisture content of the firewood before burning it. The ideal moisture content for firewood is below 20%.

Tool Calibration Standards

Proper tool maintenance is crucial for safety and efficiency. Here are some key calibration standards:

Chainsaw Sharpening: Sharpen your chainsaw chain regularly using a file or a chain grinder. A sharp chain cuts more efficiently and reduces the risk of kickback. I sharpen my chain after every few tanks of gas.
Chainsaw Bar Maintenance: Keep your chainsaw bar clean and lubricated. Check the bar rails for wear and replace the bar when necessary. A worn bar can cause the chain to bind and increase the risk of kickback.
Hydraulic Splitter Maintenance: Keep your hydraulic splitter clean and lubricated. Check the hydraulic fluid level regularly and change the fluid according to the manufacturer’s instructions. A properly maintained hydraulic splitter will operate more efficiently and last longer.

Safety Equipment Requirements

No discussion of logging or firewood preparation is complete without emphasizing the importance of safety equipment.

Helmet: A hard hat is essential for protecting your head from falling debris.
Eye Protection: Safety glasses or goggles protect your eyes from flying chips and debris.
Hearing Protection: Earplugs or earmuffs protect your hearing from the loud noise of the chainsaw.
Chainsaw Chaps: Chainsaw chaps are designed to protect your legs from chainsaw cuts.
Sturdy Boots: Sturdy boots with good ankle support are essential for working in uneven terrain.
Gloves: Gloves protect your hands from cuts, abrasions, and vibration.

Legal and Ethical Considerations

It’s important to be aware of the legal and ethical considerations associated with logging and firewood preparation.

Permits and Regulations: Obtain the necessary permits and licenses before felling trees. Be aware of local regulations regarding tree removal and firewood harvesting.
Environmental Impact: Minimize the environmental impact of your operations. Avoid damaging surrounding vegetation and wildlife habitat.
Sustainable Practices: Practice sustainable forestry techniques to ensure the long-term health of the forest. This includes replanting trees and managing the forest for biodiversity.

Common Challenges and Solutions

Here are some common challenges that hobbyists and small loggers face, along with potential solutions:

Sourcing Materials: Sourcing high-quality tools and equipment can be challenging, particularly in remote areas. Consider purchasing tools online or from reputable forestry suppliers.
Tool Maintenance: Maintaining tools can be time-consuming and expensive. Invest in quality tools that are designed for durability and ease of maintenance.
Finding Experienced Mentors: Learning from experienced loggers or arborists can be invaluable. Seek out mentorship opportunities or attend workshops to improve your skills.

Conclusion: Respect the Forest, Respect the Process

The forest is a powerful and unforgiving environment. Understanding the causes of barber chairing and implementing proper safety techniques is essential for protecting yourself and others. By combining technical knowledge with practical experience, you can safely and efficiently fell trees and prepare firewood. Remember, safety is not just a set of rules; it’s a mindset. Approach every task with caution, respect, and a commitment to doing things the right way. The sweet smell of freshly cut wood is only enjoyable when the process is approached with the proper respect and knowledge.

Barber Chair Trees Explained: Causes & Safety Tips (Pro Logging Insight)