Are brick rowlock sills or copings ever appropriate?
Brick rowlock sills or copings can be aesthetically pleasing and are appropriate in many applications. However, there are several things to consider before using them. Because brick rowlock sills and copings have many joints, considerable moisture can enter the wall. Water penetration along the top of masonry walls can contribute to efflorescence in warmer climates and both efflorescence and freeze-thaw damage in colder climates. Therefore, when using these elements in a wall system, flashing should be placed underneath the rowlock masonry. Note that the flashing in these cases will create a bond break that will separate the coping or sill from the remainder of the wall. For this reason, dowels or anchors must be used to attach a rowlock coping to the masonry below. At sills, an alternative approach is to tie the masonry to the backup wall. The dowels or anchors must be adequately sealed around the flashing to prevent leakage. In freeze-thaw environments, rowlock copings and sills often are not durable. Snow and ice can collect at the top surface of these elements. During the day, this snow and ice will melt when exposed to direct sunlight, even in below-freezing temperatures. At night, this water will freeze within the masonry. Over time, freeze-thaw cycling will break up brick copings and sills by causing deterioration of the mortar and brick. Avoiding brick sills and copings in freeze-thaw environments is typically recommended. In these climates, rowlock sills and copings will require more maintenance than the remainder of the wall. When brick sills or copings are used, they should be sloped with a 3:12 slope or greater to drain water or snow as quickly as possible.