Detail Flat Roof Joist Construction

Flat roof joist calculator.

Detail flat roof joist construction. The starting point involves laying roofing joists across the two upright items which in most cases will be the walls of the structure. 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. Underneath the basics flat roofs are usually constructed with a ceiling nailed to joists which support a deck usually wood in residential construction a vapor barrier insulation and a roof board. A waterproof exterior layer is essential and there are a number of options including bitumen based felt or asphalt epdm rubber and pvc based systems as well as cold applied liquid systems bitumen coverings.

It is for that reason that the flat roof construction manual focuses on the subject of designing energy saving flat roofs free from damage. 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 construction for residential a roof is considered to be flat when it is of a slope of 1 5o to the horizontal. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.

Other flat roof construction details often refer to the types of flat roof coverings. A flat roof usually consists of the following. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure. The full version allows any size.

This demo version is fixed at 1m clear span. 1 enter joist details 1 1 span and joist spacing. I joist construction details. This will give additional stability to the roof structure.

From there the flat roof system you choose will determine the materials you apply. It dealt in detail with flat roof constructions and. Although flat roofs are cheaper to build than pitched roofs they have a shorter life span. I joists in floor and roof applications.

For additional stability you can also use steel joists that are built into one or both of the walls. Flat roof with asphalt finish with felt boarding insulation. 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.