Hi I'm a graduate student at the University of Oregon doing some research on H-blocks (double-open-ended, speed block). While its pretty scarce around here I have heard that its relatively prolific in California (due to rebar spacing based on seismic issues). I'm coming at this from an ergonomics perspective though I am an architecture student. Does anyone have any experience designing/ working with H-block? Any info would be greatly appreciated. Thanks, Morgan

The testing agency reported that one batch of their mortar samples from my job site did not meet the specified compressive strength. Do I have to take down this area of masonry and rebuild it?

How big should the air gap be in a cavity wall?