Tips for Working with Garage Roof Trusses

Garage roof trusses support the roof in the building. They need to be carefully designed, not only to give support to the weight of the roof, but also to allow for the wind on the roof, known as dead load and wind load respectively. It’s worth knowing how to work with roof trusses, especially the things you should and should not do.


Each of the roof trusses is very carefully designed to offer the maximum strength. It has integrity. For that reason it’s vital that you should never cut into a roof truss without first talking to a structural engineer. Cutting into the wrong spot will weaken the roof and can even cause it to fall down. Each piece of the truss is there for a reason and all the angles of the timbers carefully calculated. The very simply advice is don’t mess with them.

Truss Ties

Truss ties, which are also called rafter ties, should be used in some circumstances. They’re pieces of wood that connect the oppose arms of the truss. Doing this prevents them from spreading under the weight and taking the wall beneath out of alignment. They’re only necessary where the trusses in the garage run perpendicular to the roof trusses. They need to be installed toward the bottom of the trusses, generally in the lowest third.


Roof trusses are large, heavy, and very dangerous. When installing roof trusses it’s vital to use a truss bracing system to keep them upright until they’re joined together, and also to ensure the trusses are properly spaced. The bracing will keep the trusses properly vertical, which is vital for correct measurements to be taken. Once in place and secured, the braces should be strong enough to hold the trusses firmly until everything is in place and connected. They should also have the flexibility to allow for small adjustments to the spacing.


Having the roof trusses properly connected is vital. The proper system for connection contributes greatly to the stability of the trusses, which in turn means the roof will be stable. They might be connected with glue, bolts, or in other fashions. Don’t change these, and certainly don’t cut into them, unless you obtain qualified professional advice first.

Making Your Own

It’s possible to make your own garage roof trusses. However, unless you’re a highly skilled carpenter working with an engineer, it’s not advisable. The measurements need to be precise and repeated on each truss, and all the angles for the supports have to be exact. For the vast majority of people it’s much easier and often cheaper to buy roof trusses. Forgetting one strut or having it positioned wrong can be disastrous.

How Many People?

Don’t try to work with roof trusses on your own. Putting them up requires at least two people, with more to actually help haul them up. Trying to get by with too little labor in this case can prove to be an easy road to accidents.