Proper Roof Framing
Common types of roofs and basic framing terms.
Proper roof framing. Start with a layout of a rectangular shape building. Choose the design of the roofing trusses. Choose the roofing material. So much information has been devoted to the subject of roof venting that it s easy to become confused and to lose focus.
A vented attic where insulation is placed on an air sealed attic floor is one of the most underappreciated building assemblies that we have in the history of building science. In high wind areas sheathing along the eaves rakes and ridges is nailed every 6 in. Gable a gable roof has a ridge at the center and slopes in two directions. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.
For building trusses use 2 4 lumber and make the gussets from plywood. Along the edges and every 12 in. It is the form most commonly used by the navy. Position the square at the end of the rafter board with the tongue on your left and facing away from you.
The american plywood association says there s no reduction in strength for nails overdriven by 1 16in. Depending on the roof design and the roof rafter spacing. It is simple in design economical to construct. As a general rule roofs that have a high human occupancy rate should be framed with rafters every 16 structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.
Locate a centerline at the middle section. Construction accidents occur in the thousands every year. Shed roof framing process explained step by step instructions safety first. So i ll start by saying something that might sound controversial but really isn t.
Measure form the top of this line down the board to determine the line length or length of the rafter less the ridge. Now draw a 45 degree line from each corner toward the centerline that can help to establish location specifications for. An example of each is shown in figure 2 1. If you want to frame a roof you ve got two important choices to make in terms of design.
Types of roofs the most commonly used types of pitched roof construction are the gable the hip the intersecting and the shed or lean to. Designing the roof 1. Draw a ridge line between the intersection points of the hip rafters. Install baffles providing a minimum of 1 inch of clear space between framing and or under roof decking at eaves to ensure that ceiling or roof insulation does not block ventilation paths.
Understand the different measurements. Add the length of the overhang beyond this mark and. Choose a style of roof. Building codes such as the icc s 2012 international building code section 2308 10 roof and ceiling framing typically specify that where rafter ties are used they are required at intervals ranging from 12 to 24 o c.
The framing style of the roof refers to the actual components of each.