Floor beam span tables of residential structural design we will now look at roof rafter and beam design.
Garage roof rafter design.
Continuing on from part 3.
Many of the plans use manufactured roof trusses and others use conventional rafter and joist framing.
The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.
In order to build a garage roof you need to use the following.
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.
All behm design garage plans include foundation plans and details using industry standard materials and assemblies.
Let s consider a basic gable wood roof framing design.
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.
There are certain situations where offset is more practical than opposed rafters which usually occurs on very.
Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.
Here we have a wood framed gable roof.
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.
Just enter the dimensions of the roof rise and run to get started.
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.
While this article focuses on configurations we also have a very cool set of illustrations showcasing the different parts anatomy of roof trusses.
It is always better to have a large rafter rather than be concerned with a sagging roof.
Your garage plans should include the following information to aid you when ordering the roof trusses.
C 30 pieces of 2 4 lumber 97 1 4 14 pieces 6 1 2 rafters d 14 pieces of 3 4 tongue and groove plywood sheets 4 8 decking.
A 13 pieces of 2 4 lumber 144 long bottom rafters.
If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.
If you re building rafters and aren t sure where to start when determining the length of your lumber you re in the right place our rafter stock size calculator shows you how long your rafters should be so you ll know what you need in terms of framing lumber dimensional lumber studs and more.
Our plans can be built in most us locations.
B 2 pieces of 2 4 lumber 36 1 4 1 piece of 2 6 lumber 260 top ridge.
Slope size of rafters spacing length of overhang location and size of ceiling joists size of ridge beam and any other bearing beams and load weight.