I am going to build a garage and would like to use pre-manufactured trusses with storage space. They will need to span 28 ft.
Is that easily do-able? (I'm just looking to make sure that a 26 or 27 ft truss isn't a ton cheaper than a 28 ft truss...I still have time to modify the plans)

Also, what is the maximum recommended overhang for the eaves?

Thanks,

If you are talking about conventional wood trusses for the garage roof, you won't have any storage space to speak of.

If you are talking about trusses as floor joists for the storage space above, they will be quite deep, but there will not be an appreciable difference between cost for one or two feet more span. Just be certain that the trusses are designed to handle storage loads, which are greater than normal floor loads.

And depending on which way the trusses run, be very careful with the garage door header design, because you'll have some pretty big loads on them.

Maximum overhang is a question of design...it could be almost any practical amount.

quote:

Originally posted by Keyse:
I am going to build a garage and would like to use pre-manufactured trusses with storage space. They will need to span 28 ft.
Is that easily do-able? (I'm just looking to make sure that a 26 or 27 ft truss isn't a ton cheaper than a 28 ft truss...I still have time to modify the plans)

Also, what is the maximum recommended overhang for the eaves?

Thanks,

Without knowing the type of roof cover to be used, roof pitch, any need for snow load, and wind catagory, cant really give you a difinitive answer aside from 1 or 2 foot longer in truss length not going to cost much more.

28 foot is not a great span for trusses and carrying floor dead loads will be helped by the steepness of the pitch.

As Richard has said, manufactured trusses will give you no storage space at all which means that you will have to look at hand pitched rafters or leaving a space in the middle of the trusses and using a girder at each end that are designed to carry floor joists and loads (dead 100kg/m2 and live 2-3 kpa).

With the hand pitched rafters, you will have to break the span of the bottom cord/floor truss or joist, in th middle and run another beam up in floor plane. On and on and on it goes....

Running the length of the garage, once you get over around the 5.8metre mark you will need to look into steel...

Again without the correct loads the answer is going to be vague at best.

Good luck with the project.

cheers
Paul V

Forgot to mention the overhang - usually 1/4 of the RLW (roof load width) which is half the span divided by cos the pitch divided by 4 to find out a general Max. overhang. It will depend on what type of timber you use etc etc but the general rule of thumb is 1/4 of the RLW.