Structural Timber Flat Roof Construction Details

The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure.

Structural timber flat roof construction details.

Pre manufactured roof trusses come in a wide variety of styles. On a basic level flat roof construction comes in the form of roofing timbers or joists as they are more commonly known or steels that are laid across two uprights walls in most cases. Flat roofs of this type are usually finished in steel roof sheet and fall towards a special type of gutter called a box gutter. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading.

For additional stability you can also use steel joists that are built into one or both of the walls. Of course you don t need to live in a modern house to deal with a flat roof. 2306 4 3 particleboard shear walls. Timber trusses also are built in a variety of styles using wood or metal joints.

Part b structure investigates the structural aspects of flat roofs. This could mean flat roofs may not raise the same red flags they used to. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. Besides the various loads acting on the flat roof the chapters of this section discuss potential primary structures and.

Heavy timber rafters typically spaced 240 cm 8 ft to 370 cm 12 ft apart are called principal rafters. The design shear ca pacity of particleboard shear walls shall be in accordance 2003 international building code 467 wood table 2306 3 1 continued recommended shear pounds per foot for wood structural. This article describes and illustrates the different types of support that prevents roof sagging and wall bulging at buildings including definitions of collar ties rafter ties and structural ridge beams. Some observers suggest it s harder to replace a flat roof than a traditional pitched shingle roof because of the labor required to remove its layers especially on older flat roofs.

Yet for historic modern style buildings like this old house s cambridge tv project flat roofs are at the core of the architecture meant to reflect the broad horizontal lines of the natural landscape. They are designed by the manufacturer for each specific building. But now flat roofs often are constructed with fewer layers because of improved waterproofing technology. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.

The construction of the flat roof is similar to that of the timber upper floor. This will give additional stability to the roof structure. The construction and allowable load provisions of sections 2306 3 4 and 2306 3 5. Flat roofs aren t architecturally logical as rain and snow will shed much more quickly off a sloped roof.