Cohesive Soil
A soil that when unconfined has considerable cohesion when submerged and considerable strength when air dried.
Cold-Rolled Steel
Steel rolled to the final desired shape at a temperature at which it is no longer plastic.
Cohesionless Soil
A soil that when unconfined has little or no cohesion when submerged and no significant strength when air dried.
Collar beam
Nominal 1- or 2-inch-thick members connecting opposite roof rafters. They serve to stiffen the roof structure.
Cogeneration Systems
Systems using fossil fuel, geothermal energy, wind, or solar energy to produce electricity and heat.
Cold air return
The ductwork (and related grills) that carries room air back to the furnace for re-heating.
Collar
Preformed flange placed over a vent pipe to seal the roofing above the vent pipe opening. Also called a vent sleeve.
Cohesion
The molecular forces between particles within a body which acts to unite them.
Cofferdam
A temporary watertight enclosure around an area of water-bearing soil or an area of water from which water is pumped allowing construction to take place in the water-free area.
Collector Street
A street into which minor streets empty and which leads to a major arterial.
Combustion chamber
The part of a boiler, furnace or woodstove where the burn occurs; normally lined with firebrick or molded or sprayed insulation.
Combustion air
The duct work installed to bring fresh, outside air to the furnace and/or hot water heater. Normally 2 separate supplies of air are brought in: One high and One low.
Comfort Zone
Any combination of temperature and himidity in which the average person feels comfortable.
Combined Sewer
Sewer that carries both storm water and sanitary or industrial wastes.
Compaction
Compressing soil to increase its density.
Composite Panels
Panels having a reconstituted wood core bonded between layers of solid veneer.
Composite Materials
Materials made by combining several layers of different materials.
Compression
The conditions of being shortened (compressed) by force.
Column
A vertical structural compression member which supports loads. Vertical loadbearing member.
Compartment
A small area within a larger area enclosed by partitions.