Flat Roof Joist Construction Details

What is the process of building a flat roof.

Flat roof joist construction details.

Flat roof joist calculator. The construction of the flat roof is similar to that of the timber upper floor. The major difference between the warm flat roof and the cold flat roof has to do with the air flow between the roofing timbers known as joists that help to hold up the roof. Flat roof with asphalt finish with felt boarding insulation.

In addition to floor and roof framing details this guide includes recommendations for cantilevers and placement of web holes. 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 clear span. Old asbestos roofs are often replaced with flat roofs.

Flat roof detail masonry cavity wall flat roof insulation above and between. In the warm flat roof construction there is insulation packed into every possible space where air can flow. Masonry cavity wall flat roof insulation above and between joists. The starting point involves laying roofing joists across the two upright items which in most cases will be the walls of the structure.

The full version allows any size. I joist construction details. By way of metal flat roof joist hangers. When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off.

So any timber joists that are used need to be strong enough to support this weight. Important note for cold roof construction a 50mm airspace is required for ventilation purposes over the insulation the minimum depth of joist required is usually taken as 175mm even if a lesser depth would be acceptable from a purely structural point of view ventilation details for flat roofs. I joists in floor and roof applications. Of course you don t need to live in a modern house to deal with a flat roof.

1 enter joist details 1 1 span and joist spacing. Flat roofs aren t architecturally logical as rain and snow will shed much more quickly off a sloped roof. Good installation begins with specification of the correct joist for the application. As you may imagine there is a fair amount of weight involved here in terms of boards felt etc.

Sizes of joists needed for flat roof construction. Others would treat even steeper pitches as flat roofs. Using timber wall plates. There are key differences between constructing a flat roof compared to a pitched roof and it s important to understand the basic criteria.