How to Extend an Extension Ladder Correctly: Overlap, Latches and Raising It Safely

An extension ladder should be laid flat or stood upright against the wall at a shallow angle, extended in controlled stages until the rung locks engage with an audible click, then walked into its final 75 degree working angle. The bit most people get wrong is not the lifting, it is the overlap: the sections have to stay joined by a minimum number of rungs, and cheating that to gain reach is where ladders bend and slide.

Check the ladder before you extend anything

Thirty seconds of looking beats a mid job surprise. Run your eye over the rung locks on both stiles, because a bent or seized latch is the single most common fault on an older ladder. Check the rope and pulley if yours has one, look for fraying at the point where the rope passes over the sheave, and make sure the sheave still spins rather than sitting glazed and stuck.

Then check the feet. Extension ladders live on rubber or plastic shoes that pivot, and once those are worn smooth or split, the ladder is relying on friction it no longer has. Sight down the stiles for any twist too. A section that has taken a knock will not slide cleanly and it will not sit flat against a wall either.

Two ways to extend it, and when each works

Extending it flat on the ground

For shorter double section ladders, this is the simplest method. Lay the ladder flat with the fly section facing up, push the fly section out to roughly the length you want, and confirm both rung locks have dropped onto a rung. Then raise the whole thing as one piece. This works well when you have space behind you and the ladder is light enough to walk up on your own.

Extending it upright against the wall

This is the normal method for anything long or rope operated. Stand the ladder against the wall at a shallow angle, closer to vertical than the final working position, with the base a bit tighter to the wall than you actually want it. Hold the ladder steady with one hand on a rung, pull the rope down with the other, and let the fly section run up in steady pulls rather than one heave. Keep your body out from under the moving section.

When you reach roughly the height you want, ease the rope so the latches settle onto the nearest rung. Do not stop at a half rung and assume it will drop in later. Listen for the click on both sides, then look. Two latches, two rungs, both confirmed by eye.

Get the overlap right

Overlap is the number of rungs where the two sections remain joined. It is what stops the ladder flexing into a banana under load, and it is not optional. As a general working rule used across UK guidance and most manufacturer instructions, ladders up to around 5 metres want at least three rungs of overlap, ladders from roughly 5 to 6 metres want four, and anything longer wants five or more.

The important bit: this is why an extension ladder never gives you its two sections added together. A 3 metre plus 3 metre ladder is not 6 metres extended. Subtract the overlap and you land nearer 5.4 metres, which then sits at an angle, shortening vertical reach again. If you find yourself needing every last rung, the ladder is too short for the job. Most decent ladders mark a maximum extension line on the stile, and that line is a hard stop rather than a suggestion.

Setting the final angle and footing

With the ladder extended and latched, walk the base out until you hit roughly one unit out for every four units of height, which is about 75 degrees. Stand at the base, toes to the feet of the ladder, and reach straight forward at shoulder height. If your palms meet a rung comfortably, the angle is close.

Check the base is on firm, level, non slippery ground. Both feet should be in full contact, pivoted flat. If one shoe is bridging a paving joint or perched on a stone, fix that before you climb, because a ladder that rocks at the bottom is already moving at the top.

The top should rest against something solid, with both stiles touching. Guttering, window frames and cladding are not solid. If the surface is fragile or narrow, use a stand off or stabiliser bar so the load spreads and the ladder cannot pivot sideways.

Common mistakes worth avoiding

• Extending the ladder while it is leaning at the full working angle, so the fly section drags and the latches jam.
• Standing directly underneath the moving section while pulling the rope.
• Trusting the click without looking. Latches can bounce off a rung and sit on the edge.
• Extending it while someone is on the ladder. Never do this.
• Ignoring wind. A long extended ladder catches air like a sail, both when raising and when parked.
• Retracting it by knocking the latches loose and letting the section drop. Take the weight on the rope and lower it under control.

Retracting it at the end

Reverse the process. Bring the base back in towards the wall so the ladder is steeper, take the weight of the fly section on the rope, disengage the latches, then lower in stages. Keep fingers clear of the rungs where the sections pass each other, which is where most pinch injuries on ladders happen. Once closed, lower the whole ladder to the ground before you carry it.