Roof Framing Ridge Board
Essentially the spine of a conventional stick framed roof the ridge board is sandwiched between the meeting ends of the roof rafters.
Roof framing ridge board. If you know the slope x in 12 you want to use for your roof framing design you can use it along with the run r to determine the height of the ridge beam for example if the slope is 4 in 12 and the run is 12 feet the ridge beam height m will be 4 feet. Traditional examples of the ridge board system utilize wood tension ties a k a. We will go over raft. A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to.
The ridge is the peak where two sloped roof sections meet. The ridge board s length will be the outside measurement of the building plus the length of the overhang at both ends. You may splice two boards together to achieve this length if necessary using a 14 and 1 2 inch block of the same material. And the line length measurement from the roof peak to the building wall is the hypotenuse.
This video covers one of the most exciting parts of roof framing installing rafters. The run or half the building span is the base of the triangle. 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. Collar ties rafter ties tension beams structural ridge beams.
Ridge boards can only be used in roofs with slopes from 3 in 12 up to 12 in 12. The roof rafters provide integral structural support to the roof. The rise or height of the roof at its peak is the altitude of the triangle. Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter.
If you re framing a gable roof on a new house or building a shed or even a doghouse with a gable roof you ll need to cut a number of roof rafters. Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam. Part of a roof s frame a ridge board runs horizontally along the peak of a sloped roof. For 2 x 6 rafters use a 2 x 8 ridge board and so on.
A classic example is the los altos hills remodel below by klopf architecture which uses a double 2x tension tie to sandwich each roof joist. The finished ridge beam height z above the top of the wall will be m plus the y height. Determining the ridge beam height. In part 3 of our roof framing series we cover how to select a ridge board how to layout a ridge board how to mark it so you know where to fasten the raft.
Wondering how to build the structure of your roof. Some of these can support the roof and prevent ridge sagging and wall spreading.