Head Joint

Head joints work alongside bed joints to lock a course together and transfer lateral loads between neighboring units, and like bed joints they need to be filled completely solid rather than just buttered on the visible face and left hollow behind it. A common shortcut on lower-quality work is a head joint that's packed tight at the front but empty for most of its depth, which looks perfectly fine on day one and fails early because there's no real bond holding those units to each other. Head joint spacing also has to stay consistent with the bond pattern the wall is built in, whether that's running bond or something more decorative. On a well-built wall, head joints line up in a predictable pattern from course to course, which is part of what makes a wall look plumb and intentional rather than sloppy. In running bond, the most common pattern in brick and block work, each head joint centers over the head joint two courses below it, and any drift from that pattern is usually a sign the wall wasn't laid carefully.

Hollow or thin head joints are one of the most common failure points we find when we're called out to look at older brick and block walls in this area, since water finds that gap, freezes hard over a Blue Ridge winter, and pries the joint open a little further with every freeze-thaw cycle. Solid head joints, packed full on every unit, are non-negotiable on anything we build or repoint. On a repointing job, a poorly packed head joint from the original build is often exactly where we see the worst deterioration when we open the wall up, and it's usually worse than what shows on the surface.