What to do with a flat roof over an attached double garage?
Answers:
Put deck railing around the flat roof to give the appearance of a deck. (shouldn't probably really walk on the roof, so it really is just for look).
Other answers:
you could put soil up there and have a garden.
you could put soil up there and have a garden.
It sounds like you're interested in showing the house to sell???
What is the roof style on the house itself? Was the garage an after thought when the house was built? What is its construction? Is it ACTUALLY "GLUED" to the side of the house???
I would suggest trusses and adding a pitched roof, in the same style as the rest of the house, but you mention DIY, and CHEAP in the same sentence. I often wonder why people believe that CHEAP is appealing.
In any case, is the garage sided the same as the house? If not make it so. The last thing I'll suggest is first secure the knowledge that the roof doesn't leak. Potential purchasers will care about that as much as looks. Then as a DIY you can construct a sham section, above the garage roof line, using 2 x 4's and plywood, in the shape of the existing roof line of the house. That is of course, if the house has a roofline itself.
It would be like a false wall, beginning at the house, and joined to it, construct it, as wide or wider than the garage, in the shape of a triangle, side it and treat it. The effect, from the "curb" will be what appears to be part of the garage, built on in the same style as the house and with what simulates a roof line.
What I'm talking about is essentially like a Hollywood move set piece.
Rev. Steven
Put a nice railing around it that should help
Is there access to it from the house (window or door)? If so, you might consider a roof deck. It might be worth it to install a window or door to access the deck if there isn't already one and it is accessible from the second story. A nice balustrade and some planters will make it look a lot nicer even if you don't end up turning it into a roof deck.