Flat Roof Joist Construction

If you have a low sloped roof or flat roof of less than 2 in 12 these evenly spaced planks will be called roofing joists.

Flat roof joist construction.

Having a manual for warm flat roof construction with details and a summary of rules to follow helps. 1 enter joist details 1 1 span and joist spacing. It is the responsibility of the designer of record to address items like ponding snow drift loads lateral loads wind loads bracing ventilation and insulation when adding a slope to roofs. Rolled steel joists or rsj s are used to support joists in flat roofs.

Flat roofs with a slight slope can be achieved using trus joist tji joists and solid section products. This demo version is fixed at 1m. Of course you don t need to live in a modern house to deal with a flat roof. A cavity closer should be provided to the top of the walls to prevent fire spread and to stop damp air entering the roof space.

What is the process of building a flat roof. The construction of the flat roof is similar to that of the timber upper floor. Suitable for uk building regulation approval. Maximum clear span of flat roof joists in metres for sc3 timber spacing between joists size of roof joist 400mm 450mm 600mm 47 x 97 1 84 1 81 1 74 47 x 120 2 43 2 39 2 27 47 x 145 3 08 3 02 2 87 47 x 170 3 75 3 67 3 42.

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. Flat roofs aren t architecturally logical as rain and snow will shed much more quickly off a sloped roof. The starting point involves laying roofing joists across the two upright items which in most cases will be the walls of the structure.

Ceilings and roofs excluding trussed rafter roofs for dwellings or ask your lbc surveyor for advice. Flat roof joists. 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. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.

Flat roof joist calculator. There are key differences between constructing a flat roof compared to a pitched roof and it s important to understand the basic criteria. 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. Strutting is fixed between the joists to.