From: muratlanne@gmail.com   
      
   "Richard Smith"  wrote in message news:m1347jampf.fsf@void.com...   
      
   You are folk of many and diverse talents.   
      
   In my outbuilding, to get up to the space above the horizontal roof   
   beams, I need a ladder exactly 3366mm length.   
      
   That's   
      
   (/ 3366 25.4 12) ;; 11.043307086614172 ;; ft   
   (- (/ 3366 25.4) (* 11 12)) ;; 0.5196850393700743 ;; inches   
      
   11ft length   
      
   In explanation   
      
   * 3120mm floor to roof-beam base vertically   
   * 1-to-4 rule - 1 length "out" for 4 lengths of height   
   * which means length of ladder is sqrt(17/16) of vertical height   
     (comes from "Pythagoras")   
      
   So   
      
   (+   
   (*   
     (sqrt (/ 17.0 16)) ;; 1.0307764064044151   
     3120) ;; 3216.0223879817754   
   100 ;; mm ;; the height of the roof beams   
   50 ;; just a bit more   
   ) ;; 3366.0223879817754   
      
   The idea is, that allows me to carry that ladder into the outbuilding   
   readily, then tip it upright and "catch" whichever roof-beam I want it   
   to lean against.   
      
   Then I can leave that ladder propped up vertically against the far   
   wall without being long enough to hit the roof.   
      
   How would one arrive at a ladder of exactly that length?   
   Any advice?   
      
   Rich S   
      
   ----------------------------   
      
   Shorten a longer one?   
      
   In the US ladder steps are one foot apart, 30 Cm, and about 40 - 45 Cm wide.   
      
   I made one to fit an exact space, with top end eyes that fit over fixed   
   hooks, from 2x4 (4 Cm x 9 Cm) pine wall studs with notches for the steps cut   
   on a table saw. I've made them with the steps level when upright and with   
   them nearly level when leaning, and don't notice much difference. I think   
   identical step heights is more important than the precise leaning angle.   
      
   If you don't have a power saw available a hand saw can cut tight-fitting   
   notches if you clamp vertical wood guide blocks snugly on either side of the   
   step and use them to guide the saw blade; the kerf will be within the step   
   space. For timber framing I use a pruning bow saw with a freshly sharpened   
   blade when working away from electricity or on a ladder.   
      
   A discarded and damaged aluminum ladder that I repaired and modified to work   
   on wood shed roofs has bolts through the top end (the I-beam flange) that   
   catch on rafters to stabilize it, since the lower end is on somewhat uneven   
   ground or snow/ice.   
      
   This light and stable ladder is my favorite for jobs within its reach. It   
   stores upright between the peaked roof shed's (horizontal) ceiling joists in   
   the open space between the eaves and the central catwalk.   
   https://www.homedepot.com/pep/Werner-8-ft-Aluminum-Step-Ladder-1   
   -ft-Reach-Height-with-250-lb-Load-Capacity-Type-I-Duty-Rating-368/100659876?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)