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."
Lap    To cover the surface of one shingle or roll with another.
Lap cement    An asphalt-based cement used to adhere overlapping plies of roll roofing.
Lath and plaster    The most common wall finish prior to the introduction of drywall. Thin wood strips (lath) were nailed onto the framing as a base for the sand/lime plaster.
Lintel    A horizontal structural member that supports the load over an opening such as a door or window.
Load bearing wall    A wall which is supporting its own weight and some other structural elements of the house such as the joists.
Look out    A short wood member used to support the overhanging portion of a roof.
Louver     - An opening with a series of horizontal slats so arranged as to permit ventilation but to exclude rain, sunlight or vision.
Low-slope application    Method of installing asphalt shingles on roof slopes between 2 and 4 inches per foot.