Safe and Cost-Effective Tree Felling
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The how and why of wedge cuts. February 26, 2005
Question
I have been running a chainsaw for close to 20 years now, and I have felled trees by cutting a wedge out and by just making a cut on the leaning side and one on the back side. I can't really tell any difference either way. Why is it recommended to cut a wedge out? I watched a Stihl chainsaw show on TV the other night and they were cutting a very shallow wedge that was way taller and wider than it was long and deep.
Forum Responses
From contributor R:
I knew a guy who would take the nose of the bar and plunge cut the heart of the tree out until there were only 2 or 3 ears left holding the tree. Then he would cut the ears off. He's the only person I have ever seen cut trees down that way. The last time I saw him he was keeping two skidders busy and he was 58.
From contributor J:
If the tree is well-balanced, a deep wedge is needed to offset the center of gravity, to get the tree to go the way you want it. If it is already leaning, there is probably no reason unless you just want to make sure it goes where you want it.
On low grade wood such as pulp or firewood, a notch is fine. On high dollar wood or a tree that is leaning, cut straight down the face of the tree - very shallow, maybe 2" - then cut to that downward cut horizontally. That is your wedge. Move the tip of your bar 1" back from the wedge and plunge cut through the tree horizontally and cut away from the wedge, leaving the 1" of wood as a hinge to control the tree's fall and keep the weight of the tree from pinching your bar on the way out. Cut through the back, leaving some wood just off center. Place a plastic wedge at the back of the cut and finish cutting all the wood except the hinge. On some trees that are leaning, you will not need the plastic wedge. Cutting this way gives a good deal more control of the fall and will stop end grain pull and barber chairs that can be a costly mistake for a professional logger. Also, drive by a log yard and try and find where a professional logger cut a deep wedge. You probably won't be able to because most don't.
From contributor I:
What contributor C describes is one correct felling technique. But whatever method you use, you should have a notch of some sort. The depth and angles may be varied in different situations. The purpose of the notch is to let the hinge (the area of wood just behind the notch that is left uncut) remain intact as the tree starts to fall. This controls the direction of the fall and keeps the butt connected to the stump (instead of chasing you). When the notch closes, it should snap the hinge, so you don't want this to happen until the tree is well and truly committed to its fall. A wider angle notch will let the hinge remain intact longer into the fall. Other factors are fibers pulling out of the log as the hinge breaks, or the tree hanging up or splitting if the notch closes too soon. As a general rule, always cut a notch and always leave a hinge to control the tree as it falls. The size and angle of the notch and hinge may be varied for different reasons, but it should always be there.
From contributor W:
If you have a tree of any size, it will require a fair amount of holding wood (wide hinge) to control the direction of the tree. If you only have a saw kerf on the falling side of the tree, it will not allow the tree to move very far before it closes the kerf. This is not enough force to break the hinge and the tree has not traveled far enough to ensure that it will go the way you wanted it, so you have a tree standing there stuck sorta… very dangerous. If it did break the hinge, the tree would still be fairly vertical and may not go where you planned it to go. Take a pie out and the tree is allowed to fall further before it breaks the hinge, thus giving it the momentum to keep going in the desired direction. It's a lot easier to show you than tell you.
From contributor B:
Deep cut wedges on high grade logs will get you a value deduction and you may end up losing jobs. If you are too lazy to use a wedge and hammer, you have no business in the woods! When cutting the wedge, make the vertical cut first. Then make your horizontal cut. Only cut to the vertical cut. If you cut too far on the horizontal cut, the hinge will close before the tree is down, causing the tree to split. Normally the wedge doesn't need to be more than one third the tree diameter. As far as why you need a wedge cut, it keeps the tree from splitting and, more importantly, it helps control and direct the tree as it falls.
From contributor D:
The splitting that contributor B is talking about is called a barber chair because it often leaves a vertical slab on the stump that resembles one. I have seen a 4' hemlock split up 30 feet high and have heard of trees going up 60 feet. Kind of gets your heart rate up. If you take the wedge out of the stump, it will leave a square butt. It's called a Humboldt undercut, and the mills nowadays insist on it. The undercut or wedge should be 1/4 to 1/3 of the diameter of the tree. I fall up here in British Columbia and we've all just had to be recertified by the WCB. Leave the shortcuts to the pros. Think twice, cut once.
From contributor O:
When you notch the bottom side of a beam, the cut is sloped away from the notch to reduce shear stress at the notch corner. That would be the same as the profile of an open face notch. A Humboldt notch has a flat top. My short experience with trying it in hardwood was it tended to cause splitting easier. I decided to leave it to the pros.
From contributor P:
The Humboldt and the overhand notch are both good if done right. As far as no notch… I cut timber with a guy who bragged that he had cut for thirty years without a notch. He didn't make it to thirty one. His saw didn't cut fast enough to outrun the stress on a five foot white fir. It barber chaired, and it took us over an hour to find what was left of him.
From contributor T:
I've also been cutting for over 20 years but spent the first five doing it professionally. A lot depends on the size/height of the tree, wind conditions, slope of the land, species of tree, value of tree, forest canopy, etc. Plunge cutting of any kind can be dangerous, hard on equipment and really should be left to the pros or seasoned saw operators. For most standing trees with no significant lean, I do the following up to 3 feet across. All tree felling operations should start with cutting a notch 70 degrees vertical in the direction you want the tree to go, with a horizontal cut coming next to remove the wedge. Do not overcut into the stem of the tree! Wedge cut should not be over one third into tree. Next, make your best attempt at a horizontal cut from back to front no more than one inch above the front notch. Do not under cut the notch better to go above it slightly. If needed, insert wedge behind bar of saw once you're well into the cut. Stop cut parallel to hinge, approximately 1 inch back for sound wood and further back for disease decayed wood. Pound wedge in and retreat to your safe zone of approximately 45 degrees away from stump. Don't forget saw! And always watch for dead tops witch can break off and kill!
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor A:
Hinge cutting timber is the safest way to cut standing timber. It eliminates twisting on the stump as it falls. It also stops kick-backs on the stump and also can be used to guide the tree to fall either left or right from the direction it naturally wants to fall if needed to avoid something. Others have commented on the correct amount to cut a wedge, no more than 1/3, usually about 1/4 depth of the diameter and about 70 deg.
The thickness of the hinge should be approximately 10% of the log diameter. The cut behind the hinge should be above the hinge at least 1-2 inches. This will pull splinters from the stump and not the log. Then cut away from the hinge and leave the last 4-5 inches and then cut down from the back at an angle. Hinge cutting also eliminates the possibility of pinching the saw.
The comment on plunge cutting, or as I call it drilling is the way many loggers cut walnut. The entire center is cut out leaving four spurs left on the outer edges to be cut last. This was done to avoid busting a valuable log.
