Over the past few years, a single division within one of the country’s top production homebuilders has handled claims that are a result of water intrusion in more than 700 homes in four communities. The cost to date has averaged $53,000 per home and is expected to top out at more than $37 million by the time all repairs are complete.

The two factors that minimize water intrusion are proper integration of all opening details (windows, doors, etc.) with a continuous drainage layer, and proper termination of dissimilar materials in the exterior finish (roofing, trim, siding, wood, stucco, brick, etc.). In working with the division, IBACOS Builder Services found three main causes, which were all related to the drainage plane:

• No window flashing integration
• Improper layering of the drainage plane
• Lack of a drainage plane entirely

While root causes varied from home to home, IBACOS Builder Services developed a list of eight Best Practices® that the builder could use to avoid this issue in the future:

• Fully sheath the home with a rigid sheathing, as this will allow a proper base for housewrap during install.
• Always install a housewrap material as a drainage plane.
• Install a sill pan with an end dam in window and door rough openings before the windows and doors are installed.
• Use self-stick flashing around windows and doors, and ensure it is compatible with your housewrap and windows.
• Install all drainage plane materials like housewrap and flashing in a shingle-style fashion, starting from the bottom and working your way up the wall.
• Use siding that does not inhibit adequate drainage on the surface of the housewrap and that allows drying when wetting occurs.
• Isolate water-storing brick and stucco finishes from direct contact with wood elements.
• Simplify elevations to eliminate drainage into the side of sensitive construction elements such as windows and doors.

For more Best Practices®, review our related article, “Wrapping Your Homes in Water Protection,” or sign your team up for BuildIQ's new regionalized Water Management Suite of training courses.