How To Build A 45 Degree Angle Roof

Before miter saws and even since professional carpenters used speed squares as a quick saw guide for cutting 45 and 90 degree angles.

How to build a 45 degree angle roof. Screw the gauge in place. You can make the 20 degree cut following the set angle flip the tool over and make the complementary 70 degree cut to create a perfect 90 degrees. Install the corbels next. On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length.

The square also comes with three leveling vials which make it easy to measure the pitch of existing structures. Cut a 2 4 board at that length with 45 degree angles on each end. To measure pitch first position the hypotenuse of the square on the roof running. Place the angled pieces inside your l s and screw into place to finish assembling the corbels.

Accuracy is key here because miscalculations could lead to major overspending. Screw the square gauge on the tongue at the marker for the slope pitch of the roof or the unit rise. Set unit run place the other square gauge at the run unit measurement mark. The steepest pitch for a roof is 12 12 which creates a 45 degree angle and where the roof vertically rises 12 inches for every 12 inches it goes horizontally.

To determine material quantities you need to do some calculations. Set cut angle for rafter place the framing square so the blade is horizontal on the rafter and the tongue is on the rafter and draw lines.