Foundation settlement gauge

[Mike Lamb]

Is anyone familiar with this type of foundation movement gauge? The foundation to the left of the crack was underpinned.

Edited December 2, 2018 by Mike Lamb

[Jim Katen]

That's a standard Humbolt crack gauge. I used to get them in bulk when I first started. They also had a different kind that wrapped around a corner. Haven't used them in years. 

I used a crayon to mark the date next to them. That way you could chart movement over time. If that one was installed correctly, it's showing 2mm of rotation. Without a date, that information isn't particularly helpful, though. Try to find out when it was installed, and how often it's been checked since then. Sometimes they show cyclical movement with changes in the seasons. 

 

 

[Les]

Pretty much the same as Jim K's experience.  Have not used them for several years.  I also used medical glass slides epoxied across crack - broken = movement.  What that means is what ever you want it to mean.