Flat Roof Joist Construction Details

I joists in floor and roof applications.

Flat roof joist construction details.

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. Of course you don t need to live in a modern house to deal with a flat roof. 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.

Sizes of joists needed for flat roof construction. As you may imagine there is a fair amount of weight involved here in terms of boards felt etc. In the warm flat roof construction there is insulation packed into every possible space where air can flow. Flat roof joist calculator.

What is the process of building a flat roof. Flat roof with asphalt finish with felt boarding insulation. I joist construction details. There are key differences between constructing a flat roof compared to a pitched roof and it s important to understand the basic criteria.

Using timber wall plates. 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. This demo version is fixed at 1m clear span. Others would treat even steeper pitches as flat roofs.

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. So any timber joists that are used need to be strong enough to support this weight. Old asbestos roofs are often replaced with flat roofs.

The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal however some in the industry would consider up to 15 o as their definition of a flat roof. Flat roof detail masonry cavity wall flat roof insulation above and between. The construction of the flat roof is similar to that of the timber upper floor. The full version allows any size.

1 enter joist details 1 1 span and joist spacing. Good installation begins with specification of the correct joist for the application. Flat roofs aren t architecturally logical as rain and snow will shed much more quickly off a sloped roof. 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.