Hilti currently has published technical data for the installation of HIT-HY270 into older, solid clay bricks, with a minimum 45-psi mortar shear strength with three-wythe (layers) wall construction




In some cases, similar solid clay brick walls are constructed with two wythes in lieu of three wythes. While Hilti has not specifically tested HIT-HY 270 with older, two-wythe solid clay brick construction for 6-in embedment depth, based on our experience and some limited testing of similar conditions it is estimated that the ultimate tension and shear capacities would be similar. Thus, the three-wythe wall published technical data could be used as a guideline for the two-wythe wall condition, although we recommend an on-site tension test to verify that the capacity of the anchor in the two-wythe wall condition meets the jobsite requirements for load capacity.



Note that Hilti does have testing for two-wythe and three-wythe walls for newer construction with bricks per ASTM C652 and Type N mortar with a 3,000-psi minimum prism strength and published data.