Flat Roof Deck Construction Details

Rooftop decks walk on roofs.

Flat roof deck construction details.

Photo by dave holbrook. This article discusses rooftop deck construction details to avoid building leaks or rooftop deck safety hazards. We include walk on roof surfaces roofing membrane to use below a rooftop deck and construction of rooftop deck railings and posts. Flat roofs aren t architecturally logical as rain and snow will shed much more quickly off a sloped roof.

Insulation for the warm flat roof only the basic construction process. That will help you remember certain factors and details to build the best possible flat roof. First you must make sure the roof is strong enough to support 55 lbs per square foot. Of course you don t need to live in a modern house to deal with a flat roof.

To build a flat roof you ll want to have a thorough understanding of how the process of constructing the flat roof works and the different methods available. A note to consider before construction. If insulation is installed below the flat roof deck this is called a cold roof. Some key details for a leakproof rooftop deck are.

The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal however some in the industry would consider up to 15 o as their definition of a flat roof. 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. Flat roof u value 0 18 w m2k 2 warm deck flat roof the type of insulation for this is usually of a rigid type and the thickness will vary depending on the manufacturer s specifications. They are merely placed on top of another structure.

When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off. Flat roof construction for residential. Others would treat even steeper pitches as flat roofs. These decks are often referred to as floating as they are not secured in place as a stand alone structure.

Careful detailing of membrane roofs at corners doorways and penetrations is critical for long term performance. Although flat roofs are cheaper to build than pitched roofs they have a shorter life span. Depending on the type of roof you are considering here s some technical details you may find useful. Generally roofers discourage this method for cold climates because it can promote condensation and requires ventilating the roof which may be difficult to do in small or tight spaces.

A roof is considered to be flat when it is of a slope of 1 5 o to the horizontal. The roof deck surface should sloped away from the house a minimum 1 8 inch per foot so the water will. Building a deck over a flat roof is very similar to building a deck over a concrete patio.