Roof Joist Construction Details

They are ideal for long spans including continuous spans over intermediate supports.

Roof joist construction details.

Intermediate bearing with blocking panels. I joists in floor and roof applications. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. Double the tiles at eaves and project them 1 inch over the rear edge of gutters.

So the only reason these planks are called roofing joists is because they run horizontally or nearly horizontally to the ground. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. End bearing in hanger on a top plate. While the gabled roof is always pitched in two directions the mono pitch always slants in a single direction.

I joist construction details. With single course applications nails are driven one inch above the butt line of the succeeding course. 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.

End bearing with rim board. The construction of the flat roof is similar to that of the timber upper floor. Refer to the details. In addition to floor and roof framing details this guide includes recommendations for cantilevers and placement of web holes.

Good installation begins with specification of the correct joist for the application. End bearing with rim joist. Mono pitched roofs are also known by the names of skillion roofs shed roofs pent roof and lean to roof. End bearing in hanger supported by a beam.

Lay all tiles within 1 foot of hips ridges and abutting vertical surfaces in roofer s cement. End bearing in hanger supported by i joist s 44kb. Secure each tile with two large head roofing nails. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.

Two nails are used for widths up to 8 inches. End bearing with blocking panels. Lay 10 or 12 inch tiles with 1 inch head lap on the sides of dormers. For wider shingles and shakes three nails are used.

In double coursing the under course is attached to wood sheathing with three nails or staples. Because i joists are straight and true it s easier for builders to avoid crowning and maintain a level framing surface. This will give additional stability to the roof structure. Joist is a term used in construction for load bearing planks that run horizontally or nearly to horizontally to ground.