[Greenbuilding] Insulation fasteners

[Chris Koehn]

George, Tim et al,

For long screws that are meant for attaching insulation to buildings, look for SIP screws. They are most frequently case hardened, epoxy coated, and while they don't rise to the level of an RSS (structural) screw, they are completely appropriate for what you're trying to do, and when bought in bulk should be well under $1 / ea. A quick google turned up this: <http://www.trufast.com/products/sip_nail/index.html>  
Along with screws we use large did. galv. tin washers, which keep the screw heads from pulling in too far. 
While these screws are not meant to be struck with a hammer, most are safely driven with an impact driver.

Best,

Chris Koehn
TimberGuides Design & Build
Vancouver Island, BC