Roofing Assembly Layers

Here are the layers of a roof in order of application bottom to top.

Roofing assembly layers.

The covering applied to the. Base layer attached with 1 7 8 48 mm 6d cement coated nails 6 152 mm o c. Framing includes the roof trusses that sit at the top of your house and support the weight of all the materials used to build your roof. Bur is preferred for low slope or flat roofs because it creates a continuous sealed surface.

And nails for base layer spaced 6 152 mm o c. Built up roofing also called bur is the most common roofing material used on low slope roofs. Built up roofing bur systems popular in north america for more than 100 years built up roofing bur systems are composed of alternating layers of bitumen asphalt and fabrics called roofing felts. Roofing layers from the framing to the shingles so we ll start at the bottom of the deck and work our way up through all the roofing layers until we reach the shingles and sunshine above your roof.

A roof assembly includestheroofdeck vaporretarder substrateorthermalbar rier insulation vapor retarder and roof covering. The system consists of aroof covering and roof deck or asingle component serving as both the roof covering and the roof deck. The roof decking acts as a unifying structure by tying the trusses joists together. Stagger joints between layers and on base layer of both sides.

A system designed to provide weather protection and resistance to design loads. Sound tested with studs 16 406 mm o c. Face layer attached with 2 3 8 60 mm 6d cement coated nails 8 203 mm o c. Roofing requirements for the design materials construction and quality of roof assemblies for residences are listed in the california residential code chapter 9.

You can usually see the underside of plywood decking from the attic. Decking most often made out of plywood this roof layer is installed over the framing in a typical roof install. The sy stem consists of a roof cover ing and roof deck or a single component serving as both the roof cov ering and the roof deck. All materials used in a roof assembly must be both weather and fire safe as well as compatible with each other.

We ll lay out these important pieces of the roofing puzzle and break down each one so you can fully understand the importance of each layer. The felts are reinforced with either glass fiber mats or organic mats ply sheets and when joined with the bitumen form a durable roofing membrane. It is composed of alternating layers of reinforcing fabric and bitumen asphalt and is finished with a top layer of aggregate such as stone or gravel. The roof deck is the roof layer also called sheathing that is installed between the trusses joists and underlayment layer in a typical roof install.