Another “Abq Joinery trademark” adobe detail is the way we float the window bucks. We’ve done this on the last three builds now, and it’s all to fix the issue of differential settling. This was something we noticed on our earlier projects, but it took a while to really understand it and come up with a fix. The adobe mortar shrinks and settles ever so slightly as the wall gets taller (and heavier). In our experience, a 7-8′ adobe masonry wall will lose around 3/8″ in height. And as that adobe wall shrinks, your window buck is *not* going to shrink. Eventually, you’ll end up with a stress point at the bottom of the window buck, which often results in a crack moving downward from the corners of the window buck. We used to think this crack with a superficial cracking in the plaster, but after building our exposed adobe shop we could see that it went all the way through the wall. To be clear, we’re not at all worried about this being a structural problem, but it’s something that can be easily avoided, and the principle of the thing is we just don’t like cracks in our buildings!

The workaround we’ve developed is to “float” the window during the adobe laying. We’ve either put the window up on little bits of foam, or in the case of this build we fastened it to our adobe nailers, but left a gap at the bottom of the window buck. This allows the buck to move with the wall as it settles. Once the time comes to put the actual window in, the wall has probably lost the height its gonna lose, and we fill in this gap with adobe mud.

The issue of what to do with the door bucks has been trickier, since door bucks sit on the floor. On our last project, we “floated” the door bucks, too, which was easier to do, since we had a brick floor which we could use to hide the settlement space. We didn’t have that option here, since the slab will be our finished floor. Instead, we’re trying something new, and put the settling gap above the door buck, fastening the header to the bond beam from below. Here too, the door buck will the tightened up later after the wall has a chance to settle, and the gap filled with wood or mud, depending on the situation.

#adobebuilder #doorbucks #windowbucks #adobeconstuction #adobemasonry #adobemortar #adobes #adobehouse #tmi

Mar 14, 2025