Setting up an extension ladder safely comes down to five things: choosing the right ladder, placing it on stable ground, getting the angle right, extending it to the correct height, and securing it before you climb. Each step matters because extension ladders account for a large share of ladder-related injuries, and most of those injuries trace back to setup errors rather than equipment failure.
Pick the Right Ladder for the Job
Extension ladders come in different duty ratings that determine how much total weight they can handle, including you, your clothing, and any tools or materials you carry. The ratings break down like this:
- Type IAA (Special Duty): 375 pounds
- Type IA (Extra Heavy-Duty): 300 pounds
- Type I (Heavy-Duty): 250 pounds
- Type II (Medium-Duty): 225 pounds
- Type III (Light-Duty): 200 pounds
Add up your body weight plus everything you’ll carry, and pick a duty rating that comfortably exceeds that number. A 200-pound person carrying 30 pounds of tools needs at least a Type I ladder.
Material matters too. Aluminum ladders are lighter and easier to move around, but they conduct electricity. If you’re working anywhere near power lines, overhead wiring, or electrical fixtures, use a fiberglass ladder instead. Contact between a metal ladder and a live wire can complete a circuit through your body to the ground, causing a fatal shock or triggering a fall. When there’s no electrical hazard, aluminum is perfectly fine and easier on your back.
Inspect the Ladder Before You Start
Lay the ladder flat and look it over. Check the rungs for cracks, bends, or looseness. Extension ladders have rung locks (sometimes called “dogs”) on the fly section, which are the hooks that grab each rung and hold the upper section in place when extended. If those locks are bent, loose, or missing, the fly section can slide down while you’re on it. Also inspect the rope or cable (the halyard) used to raise the fly section, looking for fraying or damage. Check the feet at the base for intact rubber pads or swivel shoes. If anything looks compromised, don’t use the ladder.
Choose and Prepare Your Ground Surface
The base of the ladder needs to sit on firm, level ground. Soft soil, gravel, or sand can shift under load and cause the ladder to kick out. On soft ground, place a wide, sturdy board (like a piece of plywood) under the feet to spread the weight and prevent sinking. Ladder mats designed for this purpose also work well.
If the ground is uneven or sloped, you have a few options. Adjustable leg levelers attach to the ladder’s feet and let you compensate for height differences between the two sides. Some extension ladders come with built-in adjustable legs. For significantly uneven terrain, you may need to level a small section of ground or use a solid plank to create a flat platform. Never stack loose materials like bricks or boxes under one leg to make up the difference. They can shift or crumble under load.
Raise the Ladder Safely
An extension ladder is heavy and awkward, and raising it wrong can strain your back or send it toppling. The standard method is a “wall raise.” Lay the ladder flat on the ground with its feet butted against the base of the wall or structure. Walk to the other end, lift it overhead, and walk toward the wall hand-over-hand along the rungs, pushing it upright as you go. The wall stops the base from sliding away while you raise it. Once the ladder is vertical and leaning against the building, you can adjust its position.
With the ladder upright and resting against the wall, extend the fly section by pulling the halyard rope. You’ll hear the rung locks click into place as each rung passes. Stop when you reach the height you need, then tug the fly section gently downward to confirm the rung locks are fully engaged. Tie off the halyard to a rung on the base section so the rope doesn’t work loose.
How Much Overlap You Need
When you extend the fly section, the two sections must overlap by a minimum amount to stay structurally sound. For ladders up to 36 feet long, maintain at least 3 feet of overlap between sections. For ladders between 36 and 48 feet, you need at least 4 feet. Less overlap than this weakens the ladder at the joint and increases the risk of the sections separating under load.
Set the Correct Angle
This is the step most people get wrong, and it’s the one that causes the most falls. Too steep and the ladder can tip backward. Too shallow and the base can slide out from under you.
The standard is the 4-to-1 rule: for every 4 feet of height where the ladder contacts the wall, move the base 1 foot away from the wall. If the ladder touches the wall at 16 feet, the base should be 4 feet from the wall. This creates an angle of roughly 75 to 76 degrees, which balances your weight between the wall and the ground in the most stable position.
If you don’t want to measure, use the elbow test. Stand at the base of the ladder with your toes touching the feet. Extend both arms straight out in front of you at shoulder height. Your palms should just barely reach the nearest rung. If you have to lean forward or your arms fall short, adjust the base until it feels right. This works because average arm length and torso proportions approximate the correct ratio.
Extend Above the Landing Surface
If you’re using the ladder to access a roof, platform, or any upper surface, the ladder needs to extend at least 3 feet above the edge where it rests, but no more than 4 feet. Those 3 feet of ladder above the roofline give you something to hold onto as you step on and off the roof. Without that extension, the transition from ladder to roof becomes a balancing act with nothing to grip, which is when people fall.
Factor this into your height calculation before you extend the fly section. If the roof edge is 20 feet high, you need the ladder to reach at least 23 feet at the contact point, plus whatever extra length the angle consumes at the base.
Secure the Top and Bottom
Once the ladder is at the right angle and height, look at what it’s resting against. Gutters are not structural supports. Leaning a ladder directly on a gutter can crush it, and the curved surface gives the ladder a tendency to slide sideways. A ladder stabilizer (also called a standoff) mounts near the top of the ladder and extends contact points out to either side, resting against the wall or fascia instead of the gutter. This widens the ladder’s footprint, reduces side-to-side wobble, and keeps the ladder clear of windows and siding you don’t want to damage.
At the base, have someone hold the ladder while you climb if possible. On smooth surfaces like concrete or tile, make sure the rubber feet are clean and making full contact. Some people stake the base or tie it off to a ground anchor, which is a good idea for any job that takes more than a few minutes. The goal is to prevent both the base from kicking out and the top from sliding sideways.
Climb With Three Points of Contact
Once everything is set, face the ladder and keep three points of contact at all times as you go up and down: two hands and one foot, or two feet and one hand. OSHA requires at least one hand gripping the ladder during any climb. Grabbing the rungs is preferable to holding the side rails because rungs give you a more secure grip if your foot slips, but holding the rails is acceptable when you need to.
Keep your belt buckle (your center of gravity) between the side rails at all times. Reaching too far to one side shifts your weight past the ladder’s base of support, which is the most common way to tip a properly set ladder. If you can’t reach something comfortably, climb down and reposition the ladder. It takes two minutes and prevents the kind of fall that can change your life.
Wear shoes with non-slip soles, keep the rungs dry, and never carry tools in your hands while climbing. Use a tool belt or haul them up with a rope once you’re in position.