Forensic Investigation of Concrete Masonry Wall Cracking

Given that concrete masonry walls are subject to shrinkage and thermal expansion and contraction throughout their life, cracking is to be expected. However, after concrete masonry walls have been placed into service, originally anticipated cracking is often perceived as damage. By its nature, this type of cracking does not constitute damage in that it does not typically compromise structural integrity. However, in some cases originally anticipated cracking is perceived as a structural concern resulting in unnecessary structural remediation. Therefore, properly diagnosing cracking in concrete masonry walls and not confusing originally anticipated cracking with structural damage can serve to prevent unwarranted concern and unnecessary remedial efforts. This paper begins by introducing the most common causes of cracking within concrete masonry walls; shrinkage and thermal expansion and contraction along with means of calculating the amounts of cracking to be anticipated. It then focuses on the types, locations, and configurations of cracking to be anticipated. This paper concludes with a discussion on the process of evaluating cracking through the use of crack mapping so as to establish relationships to originally anticipated cracking and avoid the misdiagnosis of cracking.