Residential Flat Roof Framing Detail

Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls.

Residential flat roof framing detail. Such methods use a 4 foot design module which governs a 16 inch spacing of joists studs rafters. Some roofs actually slope in several directions ensuring optimal water runoff. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. You can do this with a foam layer that exactly fits your roof.

The rise or height of the roof at its peak is the altitude of the triangle. The run or half the building span is the base of the triangle. Framing must transfer all gravity uplift and lateral loads to the foundation. The focus of this project was on connections used with conventional light frame wood roof construction.

Wood construction data 1. To keep water from pooling at these inside corners tom rips 2x4s lengthwise on a 45 degree bevel with a table saw. In buildings including residential structures framing systems typically consist of the roof structure that supports the roof deck exterior and interior load bearing walls beams girders posts and floor framing. From there the flat roof system you choose will determine the materials you apply.

This will help you create a flat roof framing plan. Typical prescriptive roof framing introduction to prescriptive roof framing 3 prescriptive roof construction the international residential code irc and the international building code ibc set out specific guidelines within which conventional light frame wood structures may be built without the need for engineering analysis of each component. And the line length measurement from the roof peak to the building wall is the hypotenuse. Cad details document name pdf dwg download all cad construction details 37 1 mb 3 4 mb mc01 identification of roof areas 694 kb 167 kb mc01a single layer underlayment 678 kb 302 kb mc01b double layer underlayment 711 kb 322 kb mc02 vent pipe flashing 626 kb 349 kb mc03 valley.

Details for conventional wood frame construction. Flat roofs are always built at a slight incline at least 1 8 inch per foot. 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. The framing of a basic gable roof is based on a right angle triangle and the various roof framing components fit the triangle.

On two sides the roof abuts a parapet a short wall common around flat roofs as well as a wall for the third floor. The construction of the flat roof is similar to that of the timber upper floor. The first approach to achieving a strong durable struc ture involving economical use of materials is to follow a basic modular plan for layout and attachment of framing members.