Home Inspection Terms – Glossary – Lally Column to Lean-to-Roof

Lally Column:  

A lally column is a steel tube, sometimes filled with concrete, used to support girders and other floor beams.

Lamella Roof Structure: 

Lamella Roof Structure is an arched, roof-framing structure composed of planking arranged in diamond shapes.

Laminate:   To build up with layers of wood that are held together in a single unit; used to produce plywood and laminated beams. One layer is called a lamination or ply.

Laminated Floor:   A floor deck made by gluing or spiking two-by-fours or planks together.

Laminated Shingles:  Strip shingles containing more than one layer of tabs to create extra thickness. Also called three-dimensional shingles.

Laminated Wood:   Wood that is laminated with the fibers or grains of the plies running parallel; as distinguished from plywood in which the grains of the plies run crosswise and only the fibers of the exterior plies are parallel.

Lap:   To cover the surface of one shingle or roll with another.

Lap Cement:   An asphalt-based cement used to adhere overlapping piles of roll roofing.

Lap Joint:   The overlapping of two adjoining pieces of timber, wallpaper or other material. Also called butt joint.

Lap Siding:   Siding used to finish the exterior surface of a house or other structure. Also called ship lap siding.

Lateral:  Relating to the side. Of or pertaining to a side; anything situated at, proceeding from or directed to a side; any line that branches off or extends from a main line. e.g., the laterals of a septic system, an irrigation distribution ditch or pipe.

Lath:   A building material of wood, metal, gypsum or insulating board that is fastened to the frame of a building to act as a plaster base.

Lateral Brace:   A wall brace which stiffens a structure against loads acting on the side walls.

Lattice:   An openwork screen of crossed strips, rods or bars of wood or metal.

Lavatory:   A place where washing is done; a wash bowl. Also, a room fitted with a wash bowl and toilet facilities.

Leaching Trenches:

Leaching trenches are trenches that carry waste liquids from sewers, may be constructed in gravely or sandy soils that allow liquids to percolate into surrounding soils or dug into firm ground and filled with broken stones, tile, gravel and sand through which liquids leach.

Leach Line:   In sewage disposal, a loose tile or perforated pipeline used to distribute sewage effluent throughout the soil.

Lead Boot:   See Collar

Lean-To:   A small structure with a pitched roof, usually erected against the outside wall of a larger structure.


A lean-to-roof is a sloping roof that is supported on one side by the wall of an adjoining building.