Electrical & Electric

How to Frame Gable Roofs

Framing a Gable Roof Made Easy

Introduction:

There are many different styles of homes that are built with gable roofs. It is the easiest roof to frame, certainly a lot easier than framing hip roofs. The gable roof construction is the most common roof design in home construction.

All the roof rafters for framing a gable roof are cut to the same size. The birdsmouth, which is the cutout that sits on the top plate, is located in the same place on all rafters. The overhang, if there is one, is also the same. Most roof designs do have some amount of overhang.

The roof ridge board, which is usually a 2 x 6, 8, 10, or 12 depends on the design weight load the roof, will have to support. The roof ridge runs the full length of the house and all the roof rafters are attached to the roof ridge. The roof ridge can be cut ahead of time and have the rafter layout marked on it.  The roof rafters permit the roof loads to transfers down the walls to the foundation.

Before any roof framing begins plywood sheathing is laid down on top of the ceiling joists along the whole length of the building. This provides a platform to stand and walk on during the construction of the roof. It's also a good idea to pass all the roof plywood up to the ceiling joists. This will make it easier to pass them onto the roof after the framing is complete.

Installing the ridge board and roof rafters:   

1.    At this point you should have all the roof rafters cut and ready to install. Install the ridge board(s) making sure the layout is going in the right direction and matches the wall stud layout. The ridge board will require some bracing to keep it in place while you attach the roof rafters.

2.    Install the roof rafters by placing them on the layout marks of the ridge board and nail them in place. If the house is a single story house the roof rafters can be leaned against the outside wall between the ceiling joists to keep them from sliding off the wall. Start by installing the first roof rafter at the end of the ridge board. Some bracing will be necessary to hold them in place. Make sure you pull the rafter in tight so the birdsmouth sits tight against the wall and the plumb cut sets flush against the ridge board. The ridge board may have to be either lowered or raised to obtain a flush fit. Install the rafter alternately on each side to keep the ridge board straight.

3.    Nail each rafter into the ridge board, at the birdsmouth, and where it passes along the ceiling joist.

4.    Install the roof sheathing.    

5.    Install the collar ties, and fascia boards.

6.    The last step is to frame in the gable ends.

That is how to frame gable roofs. Now you are ready to install the shingles.

See related articles:

Framing Walls - Wall Framing Layout

Metal Roofing

Roof Trusses

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