How To Layout A Roof Rafter

Place the square as before aligning the 6 mark of the tongue and 12 mark of the body with the top edge of the rafter material.

How to layout a roof rafter.

Floor beam span tables of residential structural design we will now look at roof rafter and beam design. Measure as precisely as possible down to the 1 4 inch 0 64 cm 1 8 inch 0 32 cm or 1 16 inch 0 16 cm. Just share the link. Layout your sheet of plywood on sawhorses.

Let s consider a basic gable wood roof framing design. The easy way to lay out and build your rafters. Continuing on from part 3. Use a tape measure to measure the entire width of your building.

Use a circular saw or jigsaw to make the cut. Draw a line down the edge of the tongue as shown in illustration b of the roof layout. Position the square with both the 8 inch on the outside edge of the tongue and the 12 inch on the blade on the upper edge of the board. On a shed roof rafter run is the distance from a ledger on the main building to the outside of an addition wall or porch carrying beam.

For every foot of run. We need to adjust the total run 73 inches in our example by subtracting 1 1 2 inches the full thickness of the ledger adjusted run 71 1 2 inches. Run is the horizontal distance that the rafter covers. Rafter layout and cutting sequence.

Rafter layout with a framing square this example is for a roof with an 8 12 pitch position the square at the end of the rafter board with the tongue on your left and facing away from you. In the gable roof example shown here a rafter with 6 in 12 pitch rises 6 in. Before you start cutting you first need to determine how long your roof rafters need to be and the angles at which you ll cut the top and bottom of the rafter. Do not download and re upload this video.

Marking the birdsmouth and the ridge board setback. Facing the long side of your material measure down from the top edge 8. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. Then draw a line across the width of the plywood from that mark.