Pythagorean Theorem Roof Framing

I haven t used the pythagorean theorem since the 1970 s as a apprentice carpenter to calculate rafter lengths.

Pythagorean theorem roof framing.

Specialized terms help to explain the triangle relationships in roof construction. Starting hint use the pythagorean theorem to fi gure the length of the rafter from the ridge board to the top plate. Example of length by calculation determine the total length of a common rafter for a building with a span of 12 ft. Pythagorean formula c 2 a 2 b 2 where a b are the legs of a right triangle and c is the hypotenuse.

Roof framing is all about right triangles but the pythagorean theorem is not widely used in calculating the lengths of the roof framing members and calculators use trigonometric ratios to calculate the lengths of the right triangles not the pythagorean theorem. Gable roofs for example are made by placing two right triangles together. Use the pythagorean theorem to calculate the rafter length. Stick built rafter steps.

Then add the length of the rafter tail. Geometry section 17 1 planning a roof 467. Pitch whether using roof trusses or stick building the roof the pitch of the roof must be selected. The pythagorean theorem is used extensively in designing and building structures especially roofs.

Apr 9 2015 the pythagorean theorem makes carpentry work so much easier when it is used for squaring walls foundations and roof framing. Align your framing square so the 10 mark and 12 mark meet the edge of your rafter stock.