Flat Roof Insulation Slope Layout

Tapered expanded polystyrene eps roof insulation was developed more than 30 years ago with a dual purpose in mind.

Flat roof insulation slope layout. Cricket length points a to b generally the longer of the 2 cross sections. Cricket width points c to d generally the shorter of the 2 cross sections. Layers of rigid insulation have staggered joints to facilitate airtightness. Cricket panel slope the slope of the cricket panel.

Today s variety of flat or low slope commercial roofing options roof pitches ranging from 12 to 3 12 is no longer simple and has grown considerably in the last 50 years. If the insulation reaches 3 or thicker an 8 by 8 creates a more gradual slope while still providing the necessary momentum. The framing system for shed roofs is straightforward and similar to that of flat roofs. R 46 unvented roof assembly two layers of r 6 5 inch rigid insulation yielding a total combined thickness of 2 5 inches.

Manufactured from lightweight foam control eps tapered expanded polystyrene eps roof insulation is a value engineered system that has been proven in new and reroof applications all over the country. There are many different types and installation methods out there along with a lot misinformation about which products offer the greatest energy savings. Roof surface slope the slope that is in the structural deck the slope created by tapered insulation or a combination of the two. Because the roof slope is steeper than for flat roofs it makes much more sense to slope the roof framing in this case to follow the roof pitch.

If insulation is installed below the flat roof deck this is called a cold roof. A typical interior roof drain assembly occupies about a 4 by 4 square area with a per foot tapered slope. A note to consider before construction. From there the flat roof system you choose will determine the materials you apply.

Built up roofs shall have a design slope of not less than one fourth unit vertical in 12 units horizontal 2 percent slope for drainage except for coal tar built up roofs that shall have a design slope of not less than one eighth unit vertical in 12 units horizontal 1 percent slope. Tapered backwashes can also help reduce the insulation height at the roof edge. There is no potential for condensation until interior moisture levels exceed 45 rh at 70 f during the coldest month. Re roofing usually entails different slope requirements.

Here we share the most common mistakes people make when installing flat roofing insulation. Two layers are preferable to one layer due to increase in air flow resistance. As a general rule if the insulation is 2 thick or less a 4 by 4 is sufficient. Roof framing members can be any number of materials depending on the span.

Consider geography budget and use for the roof to determine the best option. The goal of this article is to help building owners architects and contractors decide which commercial roofing options are right for each unique project.