Ladder Safety: Types, Sizing, and Safe Use
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Ladder falls send over 500,000 people to the emergency room every year in the US, and the vast majority of those injuries are preventable. The three causes, in order, are using the wrong ladder for the job, setting it up incorrectly, and overreaching. All three are easy to avoid once you know the rules.
Ladder Types and When to Use Each
Step ladders are self-supporting A-frame ladders that don't lean against anything. Use them indoors or outdoors for tasks up to about 12 feet off the ground (on a 10-foot step ladder — you stand on the third rung from the top, not the top). They're the right choice for painting, changing lights, shelf work, and anything where you need to work without a wall to lean against.
Extension ladders lean against a surface and are sized by their extended length. A 24-foot extension ladder reaches a two-story roofline. Use them for gutter work, painting exteriors, roof access, and tree trimming. Multi-position ladders convert between A-frame, extension, scaffolding, and stairway configurations. They're versatile for homeowners who don't want three separate ladders.
Weight Ratings
Every ladder has a duty rating that specifies the maximum weight it can safely carry — that's you plus your tools and materials combined. Type III (light duty) handles 200 pounds. Type II (medium duty) handles 225. Type I (heavy duty) handles 250. Type IA (extra heavy duty) handles 300. Type IAA (special duty) handles 375.
Most homeowners should buy at least Type I. If you weigh 200 pounds and carry a 5-gallon bucket of paint (about 60 pounds), you're already over the limit on a Type II ladder. People routinely underestimate the combined weight of themselves plus tools. Buy one rating above what you think you need. The price difference between ratings is small compared to the safety margin.
Extension Ladder Setup
The 4-to-1 rule: set the base one foot away from the wall for every four feet of ladder height. A 20-foot extension ladder should have its base 5 feet from the wall. Too steep and it can tip backward when you lean. Too shallow and the base can slide out. Most extension ladders have angle indicator stickers, but measuring is more reliable.
The ladder must extend at least 3 feet above the landing point (roof edge, for example) so you have something to hold onto when transitioning on and off. Both feet must be on firm, level ground. Uneven ground needs a ladder leveler or a leg extension — never stack boards or bricks under one leg. Lock the rung locks on both sides before climbing and give the ladder a firm shake to test stability.
Safe Climbing and Working
Three points of contact at all times: two hands and one foot, or two feet and one hand. Carry tools in a belt or bucket, not in your hands while climbing. Face the ladder when climbing and descending. Never step on the top two rungs of a step ladder or the top three rungs of an extension ladder.
Don't overreach. Your belt buckle should stay between the side rails at all times. If you need to reach further, climb down and move the ladder. This is the rule people violate most often, and it's the most common cause of ladder falls. Moving a ladder takes two minutes. A fall from a ladder can change your life permanently.
Inspection and Storage
Inspect ladders before each use. Check for bent or cracked rails, loose rungs, damaged feet, and worn rope on extension ladders. Aluminum ladders can develop stress cracks at welds. Fiberglass ladders can crack or delaminate from UV exposure. Wood ladders can crack or develop loose joints. If a ladder fails any inspection point, take it out of service. Don't try to repair structural ladder damage.
Store ladders horizontally on hooks or brackets to prevent warping. Keep fiberglass ladders out of direct sunlight when not in use — UV degrades the fiberglass over time. Store aluminum ladders away from chemicals that cause corrosion. Clean mud and debris from the feet after each use so the traction pads maintain their grip.
Frequently Asked Questions
What size ladder do I need for a two-story house?
A 24-foot extension ladder reaches about 21 feet of usable height (you lose about 3 feet for the angle and the 3-foot extension above the roof line). That's enough for most two-story houses with eaves at 18 to 20 feet. For gutter cleaning on a single-story house, a 16 to 20 foot extension ladder is sufficient. Measure the height you need to reach before buying.
Should I buy aluminum or fiberglass?
Fiberglass is the safer choice for any work near electrical lines or on the exterior of a house where overhead power lines might be present. Fiberglass doesn't conduct electricity; aluminum does. Aluminum is lighter and cheaper, which matters if you move the ladder frequently. For a homeowner buying one ladder, fiberglass is the recommendation because it handles every situation safely.
Can I use a ladder on stairs?
Not a standard step ladder or extension ladder — they require level ground on both sides or at the base. A multi-position ladder with adjustable legs can be configured for stairway use. Purpose-built stairway ladders also exist. Working on stairs with a non-adjustable ladder is one of the most dangerous common ladder misuses because the footing is inherently unstable.