We will go over raft.
Roof framing ridge board.
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.
Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam.
The finished ridge beam height z above the top of the wall will be m plus the y height.
And the line length measurement from the roof peak to the building wall is the hypotenuse.
The run or half the building span is the base of the triangle.
Traditional examples of the ridge board system utilize wood tension ties a k a.
Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter.
Part of a roof s frame a ridge board runs horizontally along the peak of a sloped roof.
Ridge boards can only be used in roofs with slopes from 3 in 12 up to 12 in 12.
The ridge is the peak where two sloped roof sections meet.
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.
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.
The framing of a basic gable roof is based on a right angle triangle and the various roof framing components fit the triangle.
Collar ties rafter ties tension beams structural ridge beams.
This video covers one of the most exciting parts of roof framing installing rafters.
For 2 x 4 rafters use a 2 x 6 ridge board.
Collar ties of a similar dimension and look as the roof joists.
Some of these can support the roof and prevent ridge sagging and wall spreading.
The roof rafters provide integral structural support to the roof.
Essentially the spine of a conventional stick framed roof the ridge board is sandwiched between the meeting ends of the roof rafters.
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.
The rise or height of the roof at its peak is the altitude of the triangle.
The ridge board s length will be the outside measurement of the building plus the length of the overhang at both ends.
A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to.
You may splice two boards together to achieve this length if necessary using a 14 and 1 2 inch block of the same material.
For 2 x 6 rafters use a 2 x 8 ridge board and so on.