How to measure for roof ladders

18 Nov 2019
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United Kingdom
Hi. Thanks for holding these forums.

Does anybody know, please, how to measure for a roof ladder or what the length dimension of for example a roof ladder Lyte 155 21 rung 5.46m ladder refers to so that I can judge the length against my roof?

Should the ladder over hang at all or end just on the tiles?

Any help will be much appreciated. I've looked for how to's, images of ladders in situ and buying guides and can't find the detail anywhere. You'll be helping me to buy right first time for a rarely to be used relatively expensive tool for the house.

Thanks a bunch,

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does your house have multi roof slopes or just two slopes - one at the back and one at the front?
you measure a roof from ridge to eaves - use a tape measure.
r/l's overhang the eaves by about three rungs when we make them on the job but bought in ladders could overhang any amount alongside the access ladder projection.

roof ladders can be a death wish in inexperienced hands.
are you youthful and fit - do you have any experience of roofing work?
Last edited:
Thanks for this bobasd,

I'm a climber and harnessed up with a tied back access ladder and a two lanyard via ferrata type set up. It's airy but quite invigorating. I have a good understanding of shifting centres of balance from being (self conferred) the Master of Lifts on a crane at work. Thanks for the concern. It's appreciated.

It's a single slope and an easy measure from an adjacent flat roof (not used for aerial access).

I think you've covered my query brilliantly and am borrowing a 5m tape from work today to make sure I've measured properly. Up to now I've just measure one tile's drop and multiplied it.

Thanks ever so much. I was amazed at how hard it was to find the detail myself.

Respect and regards

I should have said, I've done it once on a borrowed set but don't want to bother the chap again.
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You'll be helping me to buy right first time for a rarely to be used relatively expensive tool for the house.

Don't know how many sets of ladders you have, but you can buy the roof hook on it's own to attach to an existing ladder.

Obviously you will still need a ladder to get up to the roof ladder
Thanks sbck. I've only got one pair of wooden extension ladders to get me up so I have to buy a ladder at least. I have negotiated with my wife to spend a little more and get an extendable roof ladder. It'll be easier storage and I was very pleased with the rung locking mech when I borrowed a set.

I've now measured properly so thanks to diynot I'll be buying the right size first time.

Best regards


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