Shop roof?

[SecondMonkey]

I currently lease an industrial shop building, and I'm talking to the landlord about buying it when my lease expires. The shop is concrete block construction about 13' high. The roof on top is cheap 2x4 engineered trusses (no useful attic) and little slope that just makes it look bad from the outside. Ceiling is just bad, flat drywall.

If I buy it, I would really, really, really like to burn that roof off, and build the blocks up to 20' before adding a new roof. The question is what type of roof?

We're talking 30x50 here. No internal supports, needs to span the full 30'. I've got four ideas:
1. Replace with a similar, although better looking roof, no attic.
2. Replace with a more expensively constructed roof and steeper pitch so that I can use the attic space.
3. Leave the attic completely open with a "vaulted" ceiling, maybe I won't have to build the blocks up so high.
4. Flat roof - this is my favorite idea - I'd end up with a 30x50 "deck" space for god knows what.

Any thoughts on this? Right now the insulation is very, very little and I would like to fix that too. Seems like the standard, useless attic would be the easiest to insulate. Also a flat roof would eliminate the attic air space entirely, hopefully making it cooler in the summer, and possibly easier to heat in the winter. Maybe?

 

[labman]

I used to hate flat roofs, but the newer singly ply plastic and rubber seem to have solved the problem. If you go with a sloped roof, look at the standing seam metal roofs.

 

[XCELERATIONRULES]

Steeper pitch with attic.
Steel roofing panels.

 

[SecondMonkey]

Originally Posted By: XCELERATIONRULES
Steel roofing panels.

Yeah, anything except flat roof that's what I'd use.

Would it be outrageously expensive to try to make and support a flat roof out of concrete?

My issue is that my shop is the size of my lot plus a 1 car carport and 1 outdoor parking space. An extra 30x50 space on the roof would be very useful. Then again so would all that attic space...

 

[SecondMonkey]

Originally Posted By: labman
I used to hate flat roofs, but the newer singly ply plastic and rubber seem to have solved the problem. If you go with a sloped roof, look at the standing seam metal roofs.

Why did you hate them? Leaks or looks? I'm not particularly a fan of the flat roof look, but, it is an industrial shop...
(it's worth mentioning the snow load requirements around here are near zero)

 

[labman]

The old ones were sieves. When I worked for Ashland chemical in Dublin Ohio, their research center was only a couple of year old. I was on the top floor, and they had buckets setting around here and there. When they threw me out 4 years later, they still had the buckets. When it would rain, it was 3 days until water started dripping in. Then it dripped for 3 days after it quit.

 

[SecondMonkey]

I've kinda been looking at these buildings and thinking maybe it's better off to start fresh, although I like the concrete block construction.
http://www.homedepot.com/Special-Values-...catalogId=10053
Does anyone sell just pre engineered roofs that just bolt together like that?

 

[labman]

One thing to think about with truss or stick built, is getting the trusses up there. Do you have a crane/price rentals? Plenty of help? Most of my projects are one man ones. Even with a mob it is a wonder nobody got killed manually putting up the trusses on the Habitat for Humanity houses. I did a lot for them for a while, but decided life is too short to spend finishing up houses that weren't framed up square.