Per the current ESR-2269, the minimum spacing is 4 inches (4.2.3). Have a field condition where the X-U's were used to attach M550 clip (3-fasteners at 2" spacing) to concrete podium deck to secure diagonal braces/kickers. Since we are attaching to podium the fasteners were 1.25" length to avoid the tendons.
I had referenced 2015 manual at the time which permits 2.25" or even 3/4" per 3.2.4.4 (page 38) based upon the illustration.
The clips were "over-designed" at 225#/fastener (down loaded) to address construction events (spauling or missed fasteners), but not certain if the 2" vs. 4" straight-line interpetation and our design will still be sufficient.
Please advise
Hi Paris,
Hilti does not recommend deviating from the minimum fastener spacing for the X-U. Based on information in ESR-2269 and on page 19 of the Direct Fastening Product Technical Guide, the minimum fastener spacing is 4 inches.
If you would like to discuss the application further, please reach out to hnatechnicalservices@hilti.com or give us a call at 877-749-6337.
Regards,
Ashley