Framing Angled Attic

The polygon roof miter angle is the tangent of the polygon central angle divided by two.

Framing angled attic.

One half of 45 is 22 5. The rise or height of the roof at its peak is the altitude of the triangle. However the wall must be built 1 4 inch shorter than. The central angle for an octagon roof is 45.

Use the 3 4 5 triangle method to make the 90 degree angle. Use screws to attach sheets of birch plywood to the angled ceiling over the insulation making sure to drive the screws into the ceiling joists. The easiest method of framing a wall is to build it on the floor and erect it ensuring it s plumb straight up and down before securing. Run the plywood down to the top of the knee wall.

Then add the 2 4 side walls and the roof slope using a square. If you want your attic space to have a flat ceiling you ll need to add collar ties to the framing. Eliminate guesswork make a full size drawing of the gable wall on the floor of your garage or attic. Begin with a baseline and snap a center line perpendicular to it.

The plywood will create a smooth strong ceiling without having to apply drywall tape and mud to the ceiling. The tangent of 22 5 41421 laying out an octagon using a framing square we would take 12 on the blade and the number to be taken on the tongue is 12 41421 which is 4 97. And the line length measurement from the roof peak to the building wall is the hypotenuse.