When Grace Church finished the most recent phase of work on the Saving Grace project, a decision was made to leave more than 20 electronic monitors embedded in the walls to measure and record any movement. Our engineers felt that, barring a seismic event, the building would be stable and safe to occupy until the next phase of work could begin to address the structural issues in the clerestory walls ”“ the walls supported by the columns that run down both sides of the nave. Unfortunately, a seismic event in Virginia on August 23 appears to have affected the building.
On Friday, September 2, one of the electronic monitors showed significant movement. Monitor No. 19 is positioned to measure the thickness of the clerestory wall. Over a period of about 7 hours, the wall became measurably thicker. What this indicates is that the bricks that make up the wall are separating from each other, or “delaminating.” Should that process continue or speed up, it could cause the wall to fail.