The ladder angle rule is an easy way to stay safe while climbing on a ladder. Any leaning ladder such as an extension or portable straight ladder that doesn’t support itself needs the right angle to set up to keep it both sturdy and safe.
Ladder is a part of our everyday life at both home and work. It’s a convenient tool for quick and easy access to hard to reach places. But before using, you need to understand how to use it safely. Proper and safe use of ladder will help you continue working comfortably and safely without accidents.
The inclined angle of ladder is a critical factor in ladder safety. Using a ladder can be risky if you fail to angle it correctly for the distance you need to climb. It may lead to slip, which is one of the major causes of falls from heights.
This article will explain to you two methods of angle rule for ladder.
Ladder Angle Rule In-depth
Several methods have been proposed for setting up a ladder at the proper angle. Two popular ways to determine the correct ladder angle are:
- 4 to 1 Rule
- The Stand and Reach method
#1. 4 to 1 Rule
According to the 4 to 1 ratio ladder rule, your ladder should be at a 75-degree angle. The 75-degree is the 4 to 1 ratio of the pitch.
A four to one ratio for positioning a single ladder or extension ladder means that for every four feet of wall height, the bottom of the ladder must position one ft. away. In other words, for every four units of height that you’ll climb (or the working length of the ladder), you need to move the bottom (legs) of the ladder one unit away from the supporting wall.
Not clear?
Well, let’s see an example.
Suppose,
The height you need to climb= 16 feet
Following 4-to-1 rule, (16 ft. x ¼) = 4 ft.
That means you need to place the base or bottom of your ladder 4 feet away from the wall.
What will happen if you set your ladder at a wider angle and a steeper angle?
If the bottom of the ladder is very close to the wall, it’ll create a wider angle (the angle between the horizontal and ladder rail). This may cause tipping over your ladder backward.
If the base of the ladder is too far away from the wall, the inclined angle (the angle between the ladder rail and the horizontal), will be too small and the bottom can slide out.
An extremely tight angle will put too much pressure on the ladder’s sides, and it may break.
That’s not all…..
There is another quick method to set the ladder at the right angle. This method is known as “the stand and reach method”.
#2. The Stand and Reach Method
To follow this method, you’re instructed-
- To stand to face the ladder
- At the base of the ladder, place your toes against the front of the side rails
- Extend your one arm straight out.
If you can touch the rung closest to your shoulder level with the palm of your hand, your ladder is in the correct angle position.
The recommended safe angle for a straight or extension ladder is 75.5- degrees. But the average ladder inclined angle is 67.3-degree with a standard deviation of 3.22-degree.
By following the adequate precautions and ladder angle rule for safe placement of the ladder, you can minimize the risk of slipping and falling from ladder.
Follow the correct ladder angle ratio and stay safe!
Thanks for reading!
HIi Fredrick hope you are well.
I think I have a strange one for you here, in the say 10th century or later it is said that many walled cities such a Rome for example the walls were only about 30 to 35FT high. Now I’m a scaffolder and even modern ladders some of which are even banned now but they were tops 30ft to 36ft long and even that length is a pretty scary thing I tell you especially when your the first one to go up it to lash it down with rope or the 10c equivalent whatever that was. now with the angle taken into account that would be too short at a 4-1 say ratio, I’m sure you can work out the height better than me.
also, you see pictures of 7-8-9 maybe even 10 people on these things, I just can’t see how this would be done even with a modern ladder that surely would have been impossible
Ran out of space, anyway what Edward wood would lol you have to use back then I’m sure you wouldn’t get ten men on one with shields and armor swords and the rest just think about that it doesn’t make sense to me would you be kind enough to work out the angles and stuff for me? and give me your opinion on this matter.
Thanks
Stuart.
I have just one question.
If we are considering 4 ratio 1 rule with respect to the wall which is 90 degrees then according to the same rule it’s going to be 67.5 and not 75 degrees.
In my opinion
If the angle is 75 degrees then the ratio should be 3.5 ratio 1
Arctangent of 4 is 76 degrees. 4 to 1 ratio results in a 76 degree angle.
Arctangent of 3.5 is 74 degrees. 3.5 to 1 ratio results in a 74 degree angle.
For perfectionists, a ratio of 3.73 to 1 results in a 75.0 degree angle.
Tangent of 67.3 is 2.4. 2.4:1 ratio results in 67.3 degrees.
I was researching on the net for some information since yesterday night and I, at last, found what I was looking for! This is an impressive website, by the way, however, it appears a little difficult to read on my version phone.
In this example, is the ladder distance from the wall – 4 feet PLUS the distance from the roof overhang to the wall???
(or is this insignificant?)