Garage Roof Rafter Design

Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.

Garage roof rafter design. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. Then you can ensure adequate bearing points or add framing and install beams to carry the loads through the walls down to the foundation. Many of the plans use manufactured roof trusses and others use conventional rafter and joist framing. Just as there are many types of roofs with many roof parts there are many different types of roof trusses this extensive article explains through a series of custom truss diagrams the different truss configurations you can use for various roofs.

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. All behm design garage plans include foundation plans and details using industry standard materials and assemblies. Use a framing square to help lay out the notch based on the slope of the roof. Metal rafter ties make the installation of trusses easier and more secure.

As a general rule roofs that have a high human occupancy rate should be framed with rafters every 16 structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. Let s consider a basic gable wood roof framing design. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. As you can see in the image you need to cut them at the right size and secure them to the top plates with galvanized screws after drilling pilot holes.

A 2 4 wall with a 2 6 rafter can be notched for a 4 seat. Place the rafters every 24 on center if you want to get a professional result. Offset rafter framing can be done on garage roof framing if you are building a garage from plans that are sealed by a professional architect or structural engineer licensed within the jurisdiction you are building a garage in if those designs specify rafter offset. If in your plans you have an overhang rake rafter on either end of the garage you will need to adjust the measurement to insure a sheet of plywood beginning at the edge of the overhang rake will end in the center of an interior truss.

Whenever adding any type of dormer it s essential to determine the roof load and design the load path transfer to the existing floor joists or roof rafters. There are certain situations where offset is more practical than opposed rafters which usually occurs on very complicated roof framing schemes. The first step of the project is to install the bottom rafters to the frame of the garage. For our 4 x8 lean to example using a 2 4 rafter the depth of the birdsmouth is limited by the 1 3 depth of the rafter rule.

If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Our plans can be built in most us locations. Continuing on from part 3. Here we have a wood framed gable roof.