[AT] Screwing roofing

[Tom Armstrong]

When i built my shop building it came with complete instructions. It shows
exactly how to space the screws. They are all in the flats except for the
ones that stitch the panels together. The screw locations were laid out on
the sheets while they are stacked together and pre drilled with 1/4" holes
to allow for some movement with expansion. The holes in the steel purlins
are drilled with 1/8" drill and then the self drilling tapping screws
driven. The instructions said i would need about 60 drills, they were
about right. I tried expensive drills and cheap drills. They would all
break easily and often. Finally I started using a 1/2" drill to drive the
screws and let the screws do their own drilling, this worked OK if I was
in a spot where I could put a lot of weight on the drill.

Tom Armstrong  toma at sangregorio.org  San Gregorio, CA  s. 1892
Barnyard Technology--- Ideas for tomorrow -> from yesterday's scrap.
     4th, 5th, 6th generation on family farm. Can Ag Sustain?
                http://www.sangregorio.org/