Label Service (UL)
Program allowing a manufacturer to place Underwriters Laboratories Inc. labels on his products that have met UL requirements. A UL representative visits the manufacturing location to obtain samples of the products for testing by UL. In some cases, samples are also purchased on the open market for testing. The public is thereby assured that products bearing the UL label continually meet UL specifications.
Lacquer
A fast-drying clear or pigmented coating that dries by solvent evaporation.
Laminate
A material made by bonding several layers of material.
Laminate Wood
A product made by bonding layers of wood or other material to a wood substrate.
Laminated Veneer Lumber
A structural lumber manufactured from wood veneers so that the grain of all veneers runs parallel to the axis of the member.
Laminated Glass
Glass panels that have outer layers of glass laminated to an inner layer of transparent plastic.
Laminated shingles
Shingles that have added dimensionality because of extra layers or tabs, giving a shake-like appearance. May also be called "architectural shingles" or "three-dimensional shingles."
Laminating
- Bonding together two or more layers of materials.
Lap
To cover the surface of one shingle or roll with another.
Lamp
A general term used to describe the source of artificial light. Often called a bulb or tube.
Latch
- A beveled metal tongue operated by a spring-loaded knob or lever. The tongue's bevel lets you close the door and engage the locking mechanism, if any, without using a key. Contrasts with dead bolt.
Landing
A platform between flights of stairs or at the termination of a flight of stairs. Often used when stairs change direction. Normally no less than 3 ft. X 3 ft. square.
Latent Heat
Heat involved with the action of changing the state of a substance, such as changing water to steam.
Landing Zone, Elevator
The area 18 inches (5490 mm) above or below the landing floor.
Ledger (for a Structural Floor)
The wooden perimeter frame lumber member that bolts onto the face of a foundation wall and supports the wood structural floor.
Ledger Strip
A strip of lumber nailed along the bottom of the side of a girder on which joists rest. Strip fastened to the bottom edge of a flush girder to help support the floor joists.
Latex
A water-based coating, such as styrene, butadiene, acrylic, and polyvinyl acetate.
Lateral Loads
Loads moving in a horizontal direction, such as the wind.
Leaks (Sound)
Small openings at electrical boxes and plumbing, cracks around doors, loose-fitting trim and closures all create leaks that allow sound to pass through, reducing the acoustical isolation of a wall, floor or ceiling system.
Lattice
An open framework of criss-crossed wood or metal strips that form regular, patterned spaces.