Flat Roof Joist Construction

The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.

Flat roof joist construction.

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. Suitable for uk building regulation approval. 1 enter joist details 1 1 span and joist spacing. The starting point involves laying roofing joists across the two upright items which in most cases will be the walls of the structure.

Where a new flat roof abuts an existing external wall the joists can be hung on metal joist hangers which are fixed to a horizontal timber plate wall bolted to the wall. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. This demo version is fixed at 1m. There are key differences between constructing a flat roof compared to a pitched roof and it s important to understand the basic criteria.

Flat roof joist calculator. For additional stability you can also use steel joists that are built into one or both of the walls. The construction of the flat roof is similar to that of the timber upper floor. Rolled steel joists or rsj s are used to support joists in flat roofs.

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. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. 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. Strutting is fixed between the joists to.

Flat roof joists. Of course you don t need to live in a modern house to deal with a flat roof. Having a manual for warm flat roof construction with details and a summary of rules to follow helps. Joist is a term used in construction for load bearing planks that run horizontally or nearly to horizontally to ground.

Flat roofs aren t architecturally logical as rain and snow will shed much more quickly off a sloped roof. Ceilings and roofs excluding trussed rafter roofs for dwellings or ask your lbc surveyor for advice. 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. What is the process of building a flat roof.