Separation firewalls are designed to extend past the roof level and protect against spreading flames in the unlikely event of a fire. Many times these walls are simply stuccoed and painted. Over time the paint deteriorates, often at rates faster than walls due to the direct sunlight they receive, and allow moisture to seep into the wall’s core. Under a maintenance program these wall caps can be coated using an elastomeric paint sealant. Other times it is best to use some type of wall cap to permately protect the wall top area. When moisture enters the wall it causes moisture bleed out and swelling. The additional moisture content is trapped and cannot evaporate causing further damages to fasteners, flashings and framing. The swelling can rust out concrete rebar and steel straps, both structural components of the wall. The correct way to fix this is to teat the wall top as a roof and install a roof system on it. This can be achieved by installing a metal coupling or a flat roof membrane with flashing on all four sides of the wall’s top. The flat roof membrane is a better detail as it provides one continuous piece and protection without added maintenance.