[CoolJoe1941]

How can I do a "simple" an inexpensive change to the pitch on my flat roof? I am thinking I can raise the roof in the front (but I don't know how high it should be) and gradually slope it down in the back. Then put a metal roof on top of it so snow will slide off in the winter BUT I don't know what materials to use other than 2x4's. Any suggestions?

 

[jlhaslip]

Buy some trusses and install them.

 

[CoolJoe1941]

Got it . Do I have to remove the old roof first? I have never attempted anything like this before.

 

[jlhaslip]

Best way is to peel back some of the roofing material so you can support the trusses on some solid framing. The stuff in the middle can be left where it lays.

 

[carpdad]

First find out how your roof is framed. If the original flat roof joists are sitting on wall plates and the walls are on proper footing, you can start thinking of the roof as a floor. I think you have to open the ceiling all along where the load bearing walls are and find out what size wall plate, how many layers wall plate, roof joist bearing on the plate, roof joist spans, if the joists sit over the windows/doors/openings, what kind of header. How the header or supporting frame posts are supported to the foundation. Existing roof joists may need to have a rim joist or blocking. Your wall underlayment (boards or ply) may need to be cut down so that you can tie the rim to the wall.
On a floor, you can put down plate or plates and sit your trusses on the plates. If the roof deck humps, you may have to trim it. Truss spans will depend on bearing on existing structure as well as new roof. You can do the initial explorations yourself but new structure probably will need engineering. Truss maker/seller can do some of the engineering but you may need more of the above points to justify the change.