Roof framing must be designed to hold up a structural load including what is called dead load its own weight and the weight of the roof covering and additional loading called the environmental load such as snow and wind.
Attic framing details.
The framing square fig.
The face of the square is the side one sees when the square is held with the blade in the left hand the tongue in the right hand and the heel pointed away from the body.
Other roof shapes particularly those with dormers or on houses with cathedral ceilings attic rooms or attic storage areas are stick built.
Some of these can support the roof and prevent ridge sagging and wall spreading.
I learned roof framing the hardest and most maddening way possible from h h.
A collar beam adds strength to the triangle at the middle.
Collar ties rafter ties tension beams structural ridge beams.
2 5 view a consists of a wide long member called the blade and a narrow short member called the tongue.
Stick framing creates a triangle between the rafters and ceiling joists.
Actually these were compilations of articles he wrote about 100 years ago in the union magazine.
Partially these will depend on the style of roof you ve selected but you ll also have some wiggle room depending on the design elements of the house.
A composite decking made of solid materials it resembles real wood and particularly strong and stable for bearing heavy load.
This article describes and illustrates the different types of support that prevents roof sagging and wall bulging at buildings including definitions of collar ties rafter ties and structural ridge beams.
The blade and tongue form a right angle.
A horizontal timber or metal resting at the peak of the roof the rafters and trusses are connected to the ridge board for a cohesive framework.
Such methods use a 4 foot design module which governs a 16 inch spacing of joists studs rafters and panel sheathing products.
Position the square with both the 8 inch on the outside edge of the tongue and the 12 inch on the blade on the upper edge of the board.
The first approach to achieving a strong durable struc ture involving economical use of materials is to follow a basic modular plan for layout and attachment of framing members.
Gable and hip roofs may be built primarily of trusses.
Flat roofs may also need to be designed for live loads if people can walk on them.
Rafter layout with a framing square this example is for a roof with an 8 12 pitch position the square at the end of the rafter board with the tongue on your left and facing away from you.