Useful Tip:

DRILLING a PILOT hole into the treads for dense timber types. All stringers in the kits come pre-drilled ready to assemble (the stringers are the side timbers that hold the treads).  For dense timber types such as Merbau or Spotted gum, when the tread is located in the stringer you can use the pre-drilled hole in the stringer as a guide to drill a pilot hole into the tread.  While not required, it does make assembly easier.