Framing Angled Attic

The framing of a basic gable roof is based on a right angle triangle and the various roof framing components fit the triangle.

Framing angled attic.

The plywood will create a smooth strong ceiling without having to apply drywall tape and mud to the ceiling. And the line length measurement from the roof peak to the building wall is the hypotenuse. The central angle for an octagon roof is 45. The rise or height of the roof at its peak is the altitude of the triangle.

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. Begin with a baseline and snap a center line perpendicular to it. Eliminate guesswork make a full size drawing of the gable wall on the floor of your garage or attic. The polygon roof miter angle is the tangent of the polygon central angle divided by two.

Then add the 2 4 side walls and the roof slope using a square. Use the 3 4 5 triangle method to make the 90 degree angle. Collar ties are horizontal members that like rafter ties extend from rafter to rafter but. 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.

If you want your attic space to have a flat ceiling you ll need to add collar ties to the framing. One half of 45 is 22 5. However the wall must be built 1 4 inch shorter than.