Site-Built Concrete Wall Caps for Masonry Walls
Sometimes a precast cap for your masonry wall is not the best choice. Often, custom column sizes and curved walls do not work well with the limited sizes and shapes available with precast caps.
A solution to this problem … build your own cap! Although the cost for labor and material is more than that for buying and setting precast units, it can be worth it. A monolithic look on a custom column or a curved wall will change the entire look of the project — well worth the additional cost.
Forming for the cap is basic carpentry with a few tricks to make the concrete work easier. Because of the small quantities of concrete involved and the need for attention-to-detail, it is best to hand-mix the concrete on site. By doing so, it is much easier to control concrete placement and set-times (two crucial factors when finishing concrete). Placing and finishing the concrete is best done by a skilled concrete finisher — mainly due to the skill and timing necessary when stripping the side forms and finishing the short sides of the cap.
These caps are a little more work, but the customers always like the finished project!
Straight caps are the easiest to form. The caps pictured are 3" thick at the edge and crowned 1-1/2" to shed water (and improve appearance) Photo by Author
First step in forming for a cap on a curved wall - the supports. Supports set 24" o.c. Photo by AuthorAuthor
Second step - set the lower cap form (which also serves as the support for the side forms). The lower form scribes to fit the wall. Third step - Set the side forms to establish the curve of the cap. Photo by Author
Placing and finishing the concrete - Side forms are stripped during the finishing process and the side faces are troweled to match the top (including a radius edge against the lower form) Photo by Author
Determine the cap's rough cantilever dimension by adding the thickness of the veneer (if there is one) and the desired final cantilever dimension. This stone averages 1-1/2" and the desired final cantilever is 1-1/2". The cap was built-out 3" past the concrete block substrate. Photo by Author