Roof Joist Construction Details

While the gabled roof is always pitched in two directions the mono pitch always slants in a single direction.

Roof joist construction details.

End bearing with rim board. Include roof pitch roof geometry slope length and climatic factors such as heavy snowfall or rainfall. End bearing in hanger on a top plate. Mono pitched roofs are also known by the names of skillion roofs shed roofs pent roof and lean to roof.

Joist is a term used in construction for load bearing planks that run horizontally or nearly to horizontally to ground. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. With single course applications nails are driven one inch above the butt line of the succeeding course. End bearing in hanger supported by i joist s 44kb.

End bearing with rim joist. For additional stability you can also use steel joists that are built into one or both of the walls. They differ considerably from the conventional gabled roofs in shape and construction. Lay all tiles within 1 foot of hips ridges and abutting vertical surfaces in roofer s cement.

End bearing in hanger supported by a beam. Two nails are used for widths up to 8 inches. They are ideal for long spans including continuous spans over intermediate supports. The construction of the flat roof is similar to that of the timber upper floor.

Lay 10 or 12 inch tiles with 1 inch head lap on the sides of dormers. I joists are used extensively in residential floor and roof framing. For wider shingles and shakes three nails are used. Intermediate bearing with blocking panels.

Good installation begins with specification of the correct joist for the application. Refer to the details. End bearing with blocking panels. I joist construction details.

In double coursing the under course is attached to wood sheathing with three nails or staples. So the only reason these planks are called roofing joists is because they run horizontally or nearly horizontally to the ground. Double the tiles at eaves and project them 1 inch over the rear edge of gutters. Because i joists are straight and true it s easier for builders to avoid crowning and maintain a level framing surface.

In addition to floor and roof framing details this guide includes recommendations for cantilevers and placement of web holes. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. I joists in floor and roof applications. Whenever possible begin trim installation at the downwind end of the roof farthest away from the source of prevailing winds to al low flashing laps to face away from wind driven rain.