Wood Frame Flat Roof Assembly

Some roofs actually slope in several directions ensuring optimal water runoff.

Wood frame flat roof assembly.

Hi i m an architect looking for advice as to how to detail a wood frame flat roof parapet wall assembly. To frame a roof start by choosing a roof style like a frame or gabled. Closed cell spray polyurethane foam ccspf at bottom of roof sheathing. You can do this with a foam layer that exactly fits your roof.

At the highest point of the sloped roof the parapet is about 10 tall at the lowest point the parapet is about 14 tall. When framing a flat roof you will need to create a slight incline. Wood framed sloped roofs have been a common means to provide shelter and protection from the weather for centuries but high performance building enclosures often focus on wall designs rather than roof designs. For the past 10 years energy code cycles have focused on wall assemblies.

The parapet itself is standard wood framing with an applied siding in this case t g 1 4 cedar. Acceptable if above is not feasible. R value of ccspf to be 40 of total assembly. Other flat roof components 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.

6 4 flat roof assemblies before constructing a flat roof assembly please refer to the unvented roof assembly comments under 6 2 vented and unvented roof assemblies and if applicable 6 3 parapet walls. I looked for one on this website and there isn t one. Chapter 7 ceiling and roof framing 40 ceiling joists 40 flush ceiling framing 42 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. This is located in a mixed climate northern california.

Ci to be installed in multiple layers to limit insulation by pass from gapping of insulation. The assembly is straight forward but what complicates matters is that the roof needs to be vented. Flat roofs are always built at a slight incline at least 1 8 inch per foot. This will help you create a flat roof framing plan.

By flat i mean one one that is sloped to drain and either is topped with a built up roof membrane or a single ply membrane. From there the flat roof system you choose will determine the materials you apply.