Q. What are the pros and cons of using redwood stay-in-place divider strips and bulkheads for flatwork?
A. Stay-in-place wood bulkheads and divider strips produce neat joints that can be used to create a pattern of varying sizes of rectangles and squares, or to separate areas with different surface finishes. The strips also serve as contraction joints. This is especially useful with some exposed aggregate finishes for which hand-tooled joints aren't practical. For do-it-yourselfers who make small batches of concrete at the jobsite, stay-in-place forms break flatwork into smaller areas for better control of concrete placing and finishing. In many climates, a durable species of wood that's properly sealed will last many years in this application. In warm, humid areas, however, even decay-resistant wood that's been sealed may rot. Even when the concrete is in excellent condition, it's hard to make an acceptable-looking repair. Also, load transfer between adjacent panels separated by wood strips is reduced because there's no aggregate interlock. Thus, the method may not be suitable for driveways or other surfaces that will be heavily loaded.