| This project consisted of re-surfacing an 8 story building, most serious wall problems are related to water in one way or another. Water and moisture intrusion can enter wall systems in several different ways. Rainwater can enter wall systems and cladding in several different ways. It could be driven by wind, or it may enter by gravity, by capillary action, by surface tension, or by differential pressure movement.
- Gravity - Kinetic Energy - is the movement of rainwater down the face of the envelope or cladding surface, as well as over other sloped areas, into openings (such as cracks, holes, and flashing) encountered on the way down.
- Capillary Action (suction) - is the property where water will draw itself into permeable materials through small openings (such as cracks, joints, and small holes). For instance water getting sucked into a small crack similar to sucking on a straw due to various forces of air movement.
- Surface tension is the property that causes water to cling and run on to the underside of horizontal or nearly horizontal surfaces.
- Differential Pressure Movement is when water or water vapor is driven in the direction of lower air pressure from high pressure. For example, if a building has negative air (more air being exhausted than is being forced into it, it is considered to have negative pressure). Solar heating can take rain, heat it to vapor and drive it toward the interior space of a building.