When addressing moisture management it is important to recognize and accept one simple and indisputable reality: water gets into buildings. No matter how tightly a building is constructed or how well it is insulated, and no matter what type of cladding is chosen and how expertly it is installed, moisture will inevitably find a way into the building.
Weeps should create an opportunity for the liquid water that has drained down to the top surface of a flashing to exit the core or cavity of the masonry wall on the top surface of the flashing. Unfortunately, numerous unfortunate conditions have occurred because of incorrect uses of materials and devices, or detailing errors. This article examines what design professionals need to know about allowing moisture to escape their masonry.
One of the first commonly employed weep details was the sash cord or ‘rope’ weep. In some cases, this detail was expanded with sections of the sash cord laid in the cavity and then extended through the wall, usually at a head joint. In other cases, the sash cord was fastened vertically up the backside of the cavity. In yet other instances, it would be pulled out of the wall, leaving a hole through the head joint or bed joint of mortar.
In early iterations of exterior insulation and finish systems (EIFS), issues occurred when board stock rigid insulation was layered against other rigid insulation or exterior sheathing, or when decking traps moisture between the layers of material. That industry has taken steps to eliminate such problems, but what broader lessons can be learned of the importance of preventing your insulation from getting wet?
An accelerated schedule for Little Big Horn College’s Health & Wellness Center in Crow Agency, Montana, required the project team to start construction before design completion. Adding to the challenge, much of the 3250-m2 (35,000-sf) gymnasium and community facility needed to be built during one of the state’s coldest winters in 20 years.
Under an integrated project delivery (IPD) approach, the team decided to use structural insulated panels (SIPs) for the exterior walls and roof.