The building process for these steps is very similar to the process to build ramps,
described on pages 29 through 34 of this manual.
The same considerations for
landings at the door and starting construction at the top and progressing down
in a progressive fashion apply. Note that neither 3/8" bolts nor 1/2" bolts are
called for in the engineering documents for the long-tread low-riser steps.
TO HANG STAIR MODULES
Build the level landing at door.
Attach two 4x4s 39 1/2" apart to the top landing to create the opening for the
first step module.
Place the first module at the height needed to achieve your chosen riser height.
Remember that you will be adding decking to the module, so allow for the 1 1/4"
thickness of the decking.
Attach the module to the 2 4x4's with one 3" deck screw on each side.
The positioning of the module onto the 4x4s is shown.
Note that the front 4x4 is 1 1/2" from the front of the module. Also note the 1 1/2"
gap between the rear cross piece and the rear 4x4. This gap allows for
the 3 1/2" minimum riser height.
After making sure the module is level from side to side, raise or lower the
front of the module to a level position.
Place the next pair of 4x4's in position and attach module to them with
two 3" screws on each side.
add another 3" screw to each of the back 4x4s.
Install 2x6 cross supports using 2 3" screws to attach them to 4x4s.
Do not add trimmers,bracing and gussets until all modules are in place and you
are sure all risers will be equal and level.
Module is now being held in place by the cross supports. Measure down for
the next riser height and install the next module in the same manner.
After all modules have been installed and you have determined that all riser
heights are equal and modules are level, add the trimmers,braces if needed and gussets.
Diagonal bracing requires 2 3" screws at each attachment point.
Trimmers fit between the bottom of the 2x6 cross support and the 1 square foot
plywood plate and have to fit snugly, because they are weight bearing.
Trimmers require 3" screws to be 6" apart vertically. Gussets require seven 2 1/2" screws.
Place decking on modules and attach with 2 1/2" screws
Install guard rail and handrail using same techniques as described for ramps on