Plywood Roof Sheathing

The diagram shows a roof as is sometimes used over a door.To get the pointed end cut, the Square is held in position for the plumb cut of the flat roof. Then a line running from the pivot corner of the Square thru the number representing the rise of the Main Roof is the cut wanted.

When using plywood for a roof sheathing it is best to do the angle cutting on the horses as follows: from the far left hand corner of a 4 x 8 foot sheet, measure to the right the distance given for the pitch wanted (measurements given in following chart). From this point draw a line back to the near left hand corner. These measurements are for a perfectly square roof. Better check the first piece cut for any changes required.

For roofs of 6" pitch or steeper, the bevel can be cut with an electric saw that tilts to 45°. For a flatter pitched roof it is best to leave the saw set at 90° and use a valley strip made as follows: Scribe a line 1/4" from the right hand edge of a 2" piece. With the saw tilted, rip at this line. The strip should be the thickness of the roof boards at the thick edge.