Case 3

Introduction

Cracking Due To A Change In Backing Wall Materials

Type of Building: Commercial

Age of Building: Retrofitted 4 years ago

In this case, the cracks correspond to the backing wall (substrate) by its outline of the interface between the concrete beam/column frames and the brickwall. In extreme cases, staining and efflorescence from these crack lines may highlight the defect clearly which reduce the wall aesthetic appearance.

Concrete and brick behave differently under the influence of temperature and moisture due to their difference in coefficients of thermal and moisture expansion. Concrete shrinks with time while dry brick swell with time, due to the way they are manufactured.

This case is more related to differential movements due to different material properties of concrete and dry brick, rather than differential movements related to loading or settlement.

See “Concrete Cracking” for more details.