In article , Lobster
writes

If anyone's got any thoughts on these or any others, then opinions most
welcomed...


The other possible option is those ladders made up of 4 x 4 rung
sections. You can either put them up as an inverted 'w' with the board
across the two (like a scaffold board) - which would give you more
height to start with. Or, they can be set like an an inverted 'v'where
one of the legs of the inverted 'v' carries on over the top of the
other. These are designed to allow access almost from above - and often
used for cleaning roofs of vans, etc.

Trouble is, its more expense (but useful for a number of other things).

Rather than imagine inverted 'v's, have a look at:
http://www.laddersandscaffoldtowers....urpose_ladders
..html

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regards andyw