As per Anchor Fastening Technical Guide, Edition 22, Page 177, footnote 2, anchors may be installed in any location in the face of the grouted masonry wall including mortar joints.
However, as per Masonry Anchor Design Guide 2023, Page 33, footnote 4, the minimum distance from the center of an anchor to the centerline of a head joint is 2".
Both of these tables apply to HIT-HY 270 installation with threaded rods into solid grouted CMU walls. Please clarify these conflicting requirements. Thank you.
Hi Dilendra,
That is correct. The acceptance criteria for testing is different depending on whether it is LRFD or ASD. Under ASD testing, it was tested and deemed acceptable anchoring into the mortar joints for grout-filled CMU applications.
Regards,
Dani
Hi Dilendra,
These two tables are under two different design methods. Traditionally, all masonry anchors fell under allowable stress design (ASD). The code is now transitioning into strength design (LRFD) for masonry, similar to what concrete anchors are tested and designed to now. The Anchor Fastening Technical Guide is based on ASD, where the tables in the new 2023 Masonry Anchor Design Guide pertain to LRFD. There will be some variances between the two and it just depends on what the code requirements are for your specific situation.
Regards,
Dani
Hi Dilenadra,
ASD is still an acceptable design method for masonry anchors. Hilti is unable to recommend what design method to use. Typically, the code year used for design and local requirements will dictate what is required. Since buildings are normally a few years behind the code, it will take awhile for masonry ASD to become obsolete.
Regards,
Dani