Roof Rafter Terminology

When repairing or replacing a roof it pays to be familiar with these terms.

Roof rafter terminology.

Rafters which rest on the outside walls at the bottom and connect to the ridge at the top are called common rafters highlighted here in yellow. Definition of valley rafter or cripple jack rafter. Here is a closer look at common roofing terms. Roof dead load the approximate weight of roofing materials.

Ridge the horizontal line at the top of a pitched roof applies whether there is a sloping roof on both sides a duo ridge or if there is just one a mono ridge. These are short spars that run from a hip to the eves or from a ridge to a valley. A bearing timber forming part of a suspended timber floor to which the floor boards are nailed to the top and a ceiling may be attached beneath or. Length in plan of the overhang portion of the rafter.

They vary in size depending on their length and spacing. Common rafter terminology. Auxiliary cushon compound. Includes illustrations that show roofs have hip rafters ridge boards jack rafters and more.

A rafter extending from the roof ridge down to the top plate of a wall at the intersection of a gable extension roof that itself abuts or intersects with the main roof. Roof live load see snow or non snow. Hip rafter horizontal run 16 97 valley rafter ridge intersect. Rafters on opposite sides of the ridge should be installed directly opposite each other in pairs although if you see a few that don t align it s really not a defect.

Lor length of rafter this is the mathematical length from the center of the ridge to the outside of the wall. Rafter the members making up the main body of the framework of all roofs are called rafters. Application of calculations rafter lengths calculated mathematically. Principal rafter major rafter rarely a chief rafter.

They do for the roof what the joists do for the floor and what the studs do for the wall. A principal common rafter roof or double roof. Ll line length also called lor. The tops of the.

Roof framing involves a lexicon all its own. In most cases in this manual tails are added later. In the sketch above the valley rafter is drawn in yellow. Rafters are inclined members spaced from 16 to 48 inches apart.

Usually land directly on a tie beam. Bct 122 roof framing 1 rafter terminology calculations. Eave span length the horizontal length i e. Rafter a vertical sloping timber used to form the shape of the roof the side of a truss.

A term used to describe a pitched roof the ends of which are also sloped. Being smaller than a principal rafter. Definitions of rafter span run roof span slope collar ties. Tlor total length of rafter this is the total length from center of ridge to the facial cut.