Activity Industry Sector
Building & Construction Trades

Activity Originally Created By: Marty Mangan

Lay-out, cut and install the valley rafters

Part of Lesson Plan: Installing Hip and Valley Rafters - Lesson # 8

Activity Overview / Details

Activity #3:

1.     The instructor will show the students how to  lay-out, cut and install the valley rafters for the model framed house.

1 ST-  Hold the speed square, at the pivot, against the top edge of the material stock.

2 ND -  Pivot the speed square up, at the pivot, until you reach 7 on the HIP/ VAL scale.

3 RD–  At that point draw a line across the face of the board, at the top of the square.

4 TH–  On the top edge of the board, at the line drawn on the face, draw a 45 degree line down across the edge of the board to form a point at the bottom of the valley rafter.

5 TH–  Clamp the board in vice and cut the compound angle.


1.      The valley rafter is nailed to the opposite side of the inside corner of the rectangle trusses,  at the roof ridge.

2.      Then nail the other end of the rafter, at the connection of wall #2 & 6, with a 1’’ brad into the top plates.


Note: See a photo of the valley rafter location in the resources/materials.


3.      Let the valley rafter run long until you install the fascia, then cut it.

4.      The valley-jack  rafters have the same compound angle as the valley rafter, but have a 26 degree angle at the ridge.

5.       Nail the valley-jack rafters to the rectangle trusses, measured 2’’ OC from the last half truss.

5.      Nail the other end of the valley-jack rafters, to the valley rafter, parallel to the half trusses.

Note: Use a brad pusher to drive ½’’ brads through  the compound angle of all the valley rafters. At the other end of the valley rafter use a little glue and  1/2’’brads to install the valley-jacks to the rectangle trusses.







Materials / Resource