Definition of the term Roof Sheathing
The boards or sheet material fastened to the roof rafters on which the shingle or other roof covering is laid.
Definition of the term Valley Rafter
A rafter that forms the intersection of an internal roof angle. The valley rafter is normally made of double 2-inch-thick members.
Definition of the term Allowable Span
The distance between two supporting points for load bearing lumber such as joists, rafters or a girder.
Definition of the term Compression Set
The permanent deformation of a material after removal of the compressive stress.
Definition of the term Flake
A scale-like particle. To lose bond from a surface in small thin pieces. Sometimes a paint film "flakes."
Definition of the term Microlam
A manufactured structural wood beam. It is constructed of pressure and adhesive bonded wood strands of wood. They have a higher strength rating than solid saw lumber. Normally comes in…
Definition of the term Roof System
General term referring to the waterproof covering, roof insulation, vapor barrier, if used and roof deck as an entity.
Definition of the term Valley Shield
A quality underlayment for added protection in the heavy water flow areas of a roof. This self adhering product has a waterproof asphalt coating which offers excellent elongation and recovery…
Definition of the term Allowance(s)
A sum of money set aside in the construction contract for items which have not been selected and specified in the construction contract. Best kept to a minimum number and…
Definition of the term Compression Valve
A type of valve that works by raising or lowering a stem. Water passes through the valve by turning the faucet handle, which causes the stem to drop or rise.