Pythagorean Theorem Roof Framing

Gable roofs for example are made by placing two right triangles together.

Pythagorean theorem roof framing.

Then add the length of the rafter tail. Use the pythagorean theorem to calculate the rafter length. Pythagorean formula c 2 a 2 b 2 where a b are the legs of a right triangle and c is the hypotenuse. Apr 9 2015 the pythagorean theorem makes carpentry work so much easier when it is used for squaring walls foundations and roof framing.

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. Starting hint use the pythagorean theorem to fi gure the length of the rafter from the ridge board to the top plate. Roof framing is the last major framing activity in the construction of a house. The pythagorean theorem is used extensively in designing and building structures especially roofs.

Align your framing square so the 10 mark and 12 mark meet the edge of your rafter stock. Pitch whether using roof trusses or stick building the roof the pitch of the roof must be selected. I haven t used the pythagorean theorem since the 1970 s as a apprentice carpenter to calculate rafter lengths. A2 x b2 c2 your rafter length 14400 20736 35136 the square root of which 187 446 your rafter length in inches step 2 lay out your rafter.

Specialized terms help to explain the triangle relationships in roof construction. Geometry section 17 1 planning a roof 467.