Water damage is often costly to repair yet hard to initially detect. If allowed to persist, either knowingly or not, excessive amounts of moisture as a result of water infiltration can eventually lead to mold growth, and can compromise the structural integrity of a building, leading to eventual failure. Therefore, it is of the utmost importance that the exterior building envelope, which includes the roof system and exterior walls, be provided with proper water control and management details in order to prevent water infiltration and accumulation.
The proper design, construction, and maintenance of water management details pertaining to building envelope assemblies requires careful consideration and a conscious awareness of the interaction between water or moisture and building components and an adequate plan of action to ensure the long-term durability of the framing system.
Based on experience, in few cases (unless severely damaged or degraded) does water infiltrate through actual roofing material. Water entry is most prevalent at wall interfaces, transitions, penetrations, and along roof edges. The proper integration of the roofing material with underlayments, flashings, and to some degree sealants at these critical locations is essential for the suitable diversion of water into its proper drainage pathways, where it is then directed away from the building.
Similarly, exterior walls, along with their key exterior envelope components, must be designed, constructed, and maintained properly to ensure prevention of unwanted water infiltration and prolonged moisture. Again, there must be an emphasis on the proper integration of the exterior cladding with weather-resistive barriers, flashings, and sealants to direct leaking water down and away from the wall framing, where it could potentially cause serious issues.
Water intrusion associated with exterior walls is somewhat different when compared with roof systems due to their vertically-oriented nature and the law of gravity. In the case of a roof leak, water infiltrates and eventually falls down onto the interior ceiling and presents itself in the form of stains and discoloration. Leaks through the exterior wall envelope, however, may go unnoticed for extended periods of time due to the fact that as water enters, it is pulled by gravity toward the bottom of the wall and rarely presents itself on the interior finished surfaces. Based on experience, water management issues with deficient wall systems require rather extensive repairs as walls need to be shored and re-framed with newer wood structural members.