trusses or rafters

Hi All,

I'm all excited at the thought of fitting out my dream garage (funny how I'm doing this at the END of my house renovation) and I can't stop day dreaming about all the nifty shelves and cabinets I'm going to make to finally house all my precious tools and bits and pieces properly. Trouble is I have to build the garage first.

The front half will be single storey for the cars and and I'm considering making the back half of it a 1.5 storey so I can get a workshop of about 7 x7m under and an attic room for the kids to muck arouond in (and some storage for dad) above.

I'm thinking of getting all the walls made up as pre fab by a truss suppplier as this will be built on weekends and I reckon it will be easier. The lower walls will be about 2.5 high, and the upper storey will have walls about 1.8 high.

For the roof, I wonder if it is cheaper to get some special trusses made up for the attic or support the roof with rafters? The span will be 7 metres.

I reckon the trusses will cost about $5K, but may take up too much room. On the other side, I'm scared at the price of large dimension rafters and beams.

Has anybody had the same dilemma, or am I just being a tight wad and get a builder to do it?

Haydn

oregon rafters would do for the roof.
depending on your pitch and roofing type 150x50 or 200x50 should do at 1200cts

This might help size the timber
http://www.woodbin.com/calcs/sagulator.htm

If you do the work yourself the materials are a fairly small part of the cost for the main structure IMO. Depending on the roof (tile / tin) it could be the ridge beam down the centre that may cost a bit.

You can get special trusses but if you want to keep a standard pitched roof shape that will most likely take more of your internal space than rafter would.