Metal beams or lvl?

[Rolls 912]

Hi

I have a few questions re. My new garage. Any help,would be appreciated.

I'm building a 4.8m wide and 9m long clear span garage with a deck ontop. It will have a full width roller door on the 4.8m opening.

The 1st floor deck will run off our living area. the garage is built alongside the brick wall of our house. The walls of the garage will be lightweight with timber cladding.

Keen to ensure the deck is solid and doesn't bounce around. Am I best to go for lvl's or I beams? What would offer the best value?

Can the beams be drilled into for hanging things etc?

Also, I was thinking about putting a steel roof over the garage and then building the deck ontop. From what I've heard, sealed flat roofs can be problematic.

Any help would be great.
Cheers

 

[Steevo]

For a span of only 4.8m (just under 16'), I don't think you need anything more than 2x10 lumber for joists on 16" centers to support the roof itself, then add your sheathing, paper and steel material, and hang the deck joists from a plate lagged into the house, just above the flat roof, with the outer end of the joists supported by a beam or doubled rim joist that sits on short posts that align with the outer garage wall to transfer the deck load to the wall below.