A roof truss is a prefabricated framework of lumber used to assemble a roof.
Unlike rafters that are cut on site, roof trusses are engineered and built at a factory and then delivered.
There’s the bottom cord, the top cords, and then the interior webs that transfer the roof load to the walls below.
Once the walls are framed, trusses are set in place using a crane or forklift.
They’re usually spaced on two-foot centers.
I made this small section of a wall and a truss to show you how we toenail them to the top of the wall.
For a gable end truss, I like to attach an additional plate on top of the wall an inch and a half back from the edge.
This serves as a nailer on the inside for drywall and makes a great place to attach a truss- Now I can nail along the bottom cord.
Depending on what the code is where you live- you may be required to use a hurricane clip like this that attaches with nails.
Simpson also makes these truss screws- they come with a little guide, so you get the exact angle.
You just screw from the bottom of the double plate up into the truss-they’re super easy to use and don’t cause the drywall to bow.
On a big girder truss, you may need to use some heavy-duty tie-downs like these.
Let me know in the comments, do you prefer engineered trusses or cutting rafters? @hausplans
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