allen p tanner's Page

Hi Allen,
we took the bulletin board off (which showed evidence of wetting/rot on its backside) and the church reps were more than eager to do a destructive core given the many decades of trouble with this wall. So they did! We learned we have 4" block with at most a 1/2" air gap to the brick that is most likely impeded in many places by mortar. No vapor or air barrier present. There's been a lot of confusion by the church reps on when the wetness appears, which has made our theories more numerous. But at this point we have a concentrated drainage area of a large portion of roof, potential irrigation spray onto the brick, less than adequate drainage away from the brick wall, a weak drainage plane, no weeps in the wall, and some contact between the brick and concrete. Controlling water sources is primary in our minds as we think the wall is wicking bulk moisture via the wall surface and from the ground. When the morning sun hits the SE facing wall, it drives the moisture in which condenses underneath the interior wall paint. The church is replacing the bulletin board with standoffs and we are leaving our core hole open for now. So, we aim to control moisture first, and when the event happens again, take more details of the internal and external conditions when it does.

BTW when you talk about IR scanning masonry and needing to thermally load the wall, am I right you are saying to actively warm the wall? Or would the sun work if given the right conditions? I understand we want 18 degree differential ideally for all building envelope scanning, but with masonry has your experience shown you can get good thermograms with 18 degrees, or do you need active thermo loading. And if so, how do you typically load the wall?
Thanks!
TJ