Residential Wood Frame Flat Roof Details

The focus of this project was on connections used with conventional light frame wood roof construction.

Residential wood frame flat roof details. 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 literature review was conducted and supplemented with new research on the performance of conventional roof systems and components including ceiling joist to rafter connections and roof framing to wall connections. Post and beam framing 42 roof slopes 44 flat roofs 45 pitched roofs 45 valleys 48 dormers 48 overhangs 48 ridge beam roof details 49 lightweight wood roof trusses 49 chapter 8 wall sheathing 53 types of sheathing 53 corner bracing 54 installation of sheathing 54 chapter 9 roof sheathing 58 lumber sheathing 58. This will help you create a flat roof framing plan.

Such methods use a 4 foot design module which governs a 16 inch spacing of joists studs rafters. Traditional homes often have sections of flat roof over shed dormers above porches and garages and on balconies. 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. And their horizontal lines abound in the west and in urban areas.

You can do this with a foam layer that exactly fits your roof. When framing a flat roof you will need to create a slight incline. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. The construction of the flat roof is similar to that of the timber upper floor.

But flat roofs take a pounding from harsh weather which is why they rarely last as long as a good sloped roof. Normally we use 7 16 osb roof sheathing and bituminous roof membrane torch applied vents in the parapet walls and netted blown insulation. From there the flat roof system you choose will determine the materials you apply. This is known as prescriptive framing.

Wood construction data 1. They are designed with open web trusses with slope. Some roofs actually slope in several directions ensuring optimal water runoff. Details for conventional wood frame construction.

Roof snow drift surcharge a n g l e note a 15 increase in the allowable capacity of wood for loads that include snow which is a short term load snow loads 7 12 cs 0 99 slope 8 12 0 91 9 12 0 83 10 12 0 75 11 12 0 69 12 12 0 63 note that roofs exceeding an angle of 30 degrees may reduce the ground snow load. Flat roofs are always built at a slight incline at least 1 8 inch per foot. The provisions for prescriptive roof construction are found in chapter 8 of the irc and in section 2308 of the ibc. A big percentage of homes we build in the southwest nm az have flat roofs.