The trim around windows, doors, columns or piers.

Straight working line made by snapping a chalked cord stretched between two points, transferring chalk to work surface.

Total amount of heat that passes through an assembly of materials, including air spaces and surface air films. Expressed in Btu per hr., per sq. ft., per °F temperature difference between inside and outside air (beyond the surface air films). "U" values are often used to represent wall and ceiling assemblies, floors and windows. Note: "k" and "C" values cannot simply be added to obtain "U" values. "U" can only be obtained by adding the thermal resistance (reciprocal of "C") of individual items and dividing the total into 1.

Amount of heat (in Btu) that passes through a specific thickness of a material (either homogeneous or heterogeneous) per hr., per sq. ft., per °F. Measured as temperature difference between surfaces. The "C" value of a homogeneous material equals the "k" value divided by the material thickness: C = k/t (where t = thickness of material in inches)

It is impractical to determine a "k" value for some materials such as building paper or those only used or formed as a thin membrane, so only "C" values are given for them.

See Thermal Expansion.

Force that presses particles of a body closer together.

Generally, the wide, lower part of a foundation wall that spreads the weight of the building over a larger area. Its width and thickness vary according to weight of building and type of soil on which building is erected.