Glossary

Valley: The inward angle formed by two intersecting, sloping roof planes. Since it naturally becomes a water channel, additional attention to waterproofing it is desirable.

Valley Shield: A quality underlayment for added protection in the heavy water flow areas of your roof. This self adhering product has a waterproof asphalt coating which offers excellent elongation and recovery properties for accommodating roof expansion and contraction and structural movement.

Vapor Barrier: Moisture resistant materials used to stop or slow the movement of moisture through a surface. Often applied on the inside face of exterior walls to prevent condensation forming in interior living areas.  Examples are Tyvek and tar paper.

Vent: Any outlet for air that protrudes through the roof deck, such as a pipe or stack. Any device installed on the roof, gable or soffit for the purpose of ventilating the underside of the roof deck.

Voltage: A measure of electrical potential.

• Most homes are wired with '110' and '220' volt lines. The '110' volt power is used for lighting and most of the other circuits. The '220' volt power is usually used for the kitchen stove. water heater and dryer. (The terms '110' and '220' volts are a short hand, e.g. a '110' volt line is usually rated at 117 volts plus or minus 10%).