In case of attaching a roof deck to steel joist, mostly the thickness of steel joist top chord is unknown because the joists are designed by the joist manufacturer and angle sizes are unknown. In the past, I have made an assumption on thickness unless is verified in field. What's Hilti's approach on this?
Hello Tom,
In terms of installation into bar joists as the support steel for PAF decking frame fasteners, engineers typically consider the X-HSN 24. Per page 158 of Hilti’s Direct Fastening Technical Guide, this fastener is applicable for thicknesses of 1/8“ through 3/8“. While support steel thickness should still be verified to ensure the appropriate fastener is being used as determined by the Engineer of Record on the project, the X-HSN 24 thickness range is intended to cover the typical ranges of thicknesses observed for bar joists.
Page 158 of the Direct Fastening Technical Guide also gives an overview of the other Hilti frame fasteners and their corresponding support steel thicknesses, including the PAF X-ENP 19 for supports 1/4" and thicker, as well as some screw options such as the S-RT5+ and the S-RT5.
Best,
Sinan