Extension ladder ratings

mkirsch · Oct 1, 2014

An extension ladder has to be able to safely support its rated weight limit at full extension. Any section by itself also has to safely support its rated weight limit.

Wouldn't it stand to reason that a 250lb rated two-section extension ladder, completely retracted, would be good for 500lbs?

Zachary Hoyt · Oct 1, 2014

Only if the weight was distributed equally across both rungs where
the person was standing. My opinion is that if you weigh 500 lbs
probably a ladder is not a great place to be, even if it is strong
enough to hold you.
Zach

bjb in TX from Ne · Oct 1, 2014

Depends on the limiting factor. If the steps are only rated at 250# each, then you can stack multiple ladders and still have the 250# limit. Secondly with it fully retracted, both section do NOT set on the ground, which means at some point you are still putting 500# on a single section. This sort of situation is similar to what happened in the Kansas City Hyatt hotel walkway collapse in the 80's.

Dick2 · Oct 1, 2014

You are correct; the ladder is rated for the weakest link. The pounds may be by calculations instead of actual failure testing.

Supposedly the ladders are designed with a 25% safety factor, again probably by calculation. Depends on how much you want to press your luck by going above the rating. Personally, I would go over 10% - but the risk is with the user. Just have good insurance, in case you end up in a heap on the ground.

NNP · Oct 1, 2014

probably if you actually took it apart and just used half sections, you could up the weight.
I look at my ladders pretty close (treestands too)
because I am just about at the limit of cheap ones at 240.(with gear, far over)
ladders and rungs look ok, but the hook mechanisms and their pins look weak. And the actual seam where they slide together looks the weakest of all. I could imagine that flexing apart at high extensions. So I always use extreme vertical and tie it off after the first scary climb.

(where exactly do they make these things where 250 is the high max, and not the normal person. Most people I know are bigger than I am......)

dr sportster · Oct 2, 2014

The Hyatt Hotel was caused when rods were shortened and nutted instead of running as one long rod all the way through. The rods as long form would have been very hard to handle on a construction site. The design was marginal as first drawn . Then when the rods were shortened and nuts used : disataster . 114 killed. Another uncontrollable engineering factor was the amount of load ]people on the platforms at any one time . Total load was not really known.

mkirsch · Oct 2, 2014

I don't weigh 500, but suffice it to say I require Class 1A ladders, which are only available as fiberglass, and tend to be very heavy and unweildy compared to aluminum.

Recent building projects have shown me to be deficient in the ladder department, so I've been shopping. I currently only have one ladder, a "Little Giant" knockoff that is built like a brick ---house and has never given me a reason to worry. It's just a pain to keep switching from straight ladder mode to step ladder mode when installing joists on a lean-to.

big fred · Oct 2, 2014

I maxed out at 277 lb (I've lost weight since then) and I had no problems using a ladder rated at 225. It got pretty "dancey" at midpoint when it was fully extended, but held me. That ladder was a 24 ft Werner fiberglass extension ladder at least 20 years old at the time.

Extension ladder ratings

mkirsch

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Zachary Hoyt

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bjb in TX from Ne

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Dick2

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NNP

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dr sportster

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mkirsch

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big fred

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