I need to cut down a tree in my backyard that's half dead but first need to figure out how tall the tree is so I can rent appropriate height manlift. The 60' manlift is 400+ bucks cheaper than the 80' manlift. I don't mind spending the extra money for the 80' manlift but if I can save 400 bucks I'd rather get the 60'. Looking for a reliable way to estimate the height of the tree to help me decide which manlift to rent.

Trigonometry.

Google it; there are several methods.

You can use this calculator if you have a long tape measure and a simple protractor.

https://www.calculator.net/rig...ngle-calculator.html

Find a convenient spot to stand where you can see the top of the tree, or the point that you want to measure the height to. Measure the distance from that spot to the base of the tree. That is your value b for the calculator input.

From the same spot, determine the angle you’re looking up at to the same spot on the tree. That is your angle α for the angle input.

When you calculate, value a is the height.

Note that measuring the angle will normally be from your head height, and therefore you would add that to whatever the calculated a value was. And also note that when using that calculator, clear out the values from the other fields.

If you can find someone with one, some laser rangefinders such as the type used in various construction fields or forestry will automatically calculate the height of an object by measuring the lasing distance and look angle.

The stick and shadow method

Apparently you can do it from the diameter of the trunk!

Allometry relation for tree trunk diameter and height.

Well first you need to buy a monkey...

What's the cost of having a professional tree service take it out?

If there is any chance the tree could drop on someone else's property, hiring a company that has insurance might make a lot of sense.

Given the current economic challenges, you might get a real deal if you call someone now

quote:

Originally posted by SR:
What's the cost of having a professional tree service take it out?

If there is any chance the tree could drop on someone else's property, hiring a company that has insurance might make a lot of sense.

Given the current economic challenges, you might get a real deal if you call someone now

It will cost double the price of the manlift to pay a professional to cut down the tree. Plus theres a second slightly smaller tree I also intend to cut down as well as cut some branches on several other trees so my grass receives more sunlight. I have some painting I want to finish on my house that I can't reach with a ladder. The tree does not extend over anyone's property so fortunately that is not an issue.

1. Climb halfway up tree.
2. Cut off top half of tree and allow it to fall to the ground.
3. Climb down and measure cut off half.
4. Multiply by 2 to get original height of tree.

We have the technology:
1) Drone
2) Laser based 'tape' measure. Contractors, realtors use it to measure room size and other distances.

Rig up a drone w/ the laser measure. Fly drone to top of tree. Measure distance to ground.

Easy peasey and cool.

Or you should just fly a drone up to the top of the tree and use the laser measure from the ground to find distance to the drone. Easy but not as McGyver-ish.

BTW - just kidding. No idea how trees are measured. Following the thread with curiosity.

If you have the space you can't beat the old Boy Scout pencil method

quote:

Originally posted by Sig2340:
1. Climb halfway up tree.
2. Cut off top half of tree and allow it to fall to the ground.
3. Climb down and measure cut off half.
4. Multiply by 2 to get original height of tree.

You went to A&M, didn’t you?

quote:

Originally posted by konata88:
We have the technology:
1) Drone
2) Laser based 'tape' measure. Contractors, realtors use it to measure room size and other distances.

Rig up a drone w/ the laser measure. Fly drone to top of tree. Measure distance to ground.

Easy peasey and cool.

Or you should just fly a drone up to the top of the tree and use the laser measure from the ground to find distance to the drone. Easy but not as McGyver-ish.

BTW - just kidding. No idea how trees are measured. Following the thread with curiosity.

Hobby/commercial level Drones automatically report their altitude to the controller.

quote:

Originally posted by straightshooter01:

Hobby/commercial level Drones automatically report their altitude to the controller.

Can't afford an drone. Did not know that. That's actually pretty cool. There are times I wish I had a drone and high res camera.

quote:

It will cost double the price of the manlift to pay a professional to cut down the tree. Plus theres a second slightly smaller tree I also intend to cut down as well as cut some branches on several other trees so my grass receives more sunlight. I have some painting I want to finish on my house that I can't reach with a ladder. The tree does not extend over anyone's property so fortunately that is not an issue.

It sounds like you have a plan.
Just curious why you have to start at the top?
Can you tell which way it wants to fall (usually to the downhill side)? Will it hit anything if you just fell it from the bottom?

quote:

Originally posted by 2000Z-71:
Trigonometry.

Or gee I'm a tree.

With a protractor, string, and a weight: put one end of the string trough the hole in the protractor, tie a knot so the string doesn't pull back through the hole, and tie the weight. Hold the protractor such that the string hangs freely next to the degree markings on the protractor. Walk back away from the until the string hots 45 degrees when you sight down the length of the protractor to the top of the tree. Walk back towards the tree counting your paces. Multiply your paces times three, add 5, and that's the height, in feet, of your tree within about 5 feet.

The geometry explanation is the tree forms a right angle with the ground. When you measure a 45 degree between the top of the tree and the ground the adjacent nonright angle must be 45 degrees because the sum of the angles of a triangle is 180 degrees. A right triangle whose other angles are congruent is an isocolese triangle, so the two nonhypotenuse sides are also congruent. Congruent sides have the same measurement, so when you pace back to the tree, you get the height of the tree, but you have to asd 5 feet because you were standing up when you got the 45 degree measurement on thr protractor.

quote:

Originally posted by chellim1:
Just curious why you have to start at the top?

If he knows what he's doing: He won't.

You start at the bottom, limbing the tree as you work your way up. Then you work your way down, cutting off sections of the trunk until you have something manageable.

But doing this, particularly the trunk parts on the way down, requires a degree of skill. And ropes. Long, heavy ropes. And people to haul on them with enough sense and ability to get and stay the hell out of the way.

quote:

Originally posted by chellim1:
Can you tell which way it wants to fall (usually to the downhill side)?

Not really. Trees tend to grow straight(-ish) up, not square to the slope. It's more a question of the balance of the tree, wind direction and strength, and internal stresses (which you can't really tell).

Felling entire trees in one go is something best left to pros, IMO. None of our tree crews have ever done it that way.

Even when I take down smaller trees myself I limb them as far up as I can before felling them.

Live wood is unpredictable.

Hit up YouTube and enter "tree cutting fails" or the like.

Hire that Sigmonkey guy, he’ll work for a 6-pack of bananas.