Portable garages come in several shapes, some of which may accommodate your needs better than others. One common type of portable storage building is a rounded roof shelter, which has a tall, curved frame and is usually used for longer vehicles like RVs. Smaller versions are available but, generally, portable garages with rounded roofs are used for longer vehicles. The frame for this shelter, which can be seen in the Shelters of America YouTube video below, is essentially composed of curved pieces of galvanized steel – all of the same size – connected together by straight pieces of steel.
Rounded roof portable garages have the same composition as other types of portable shelters, with a galvanized steel frame and a polyethylene canopy. Rounded roof portable buildings are better suited to certain climates, however. In general, a portable garage frame and canopy should withstand faster winds and large amounts of snow or rain, but rounded roof portable garages are better suited for people needing storage in areas experiencing large rain and snow falls. The rounded design allows snow or rain to simply roll off the roof and not accumulate on top.
In terms of assembly, as you can see by the video above, the polyethylene canopy stretches from one side to the other, once the frame as been assembled. As a shelter, this fully-enclosed design, as soon as you add back and front polyethylene zipper doors, is ideal for protecting vehicles or other investments that will be in storage for several months. This includes RVs, boats, motorcycles, and farm equipment. For all-around coverage, the polyethylene canopy keeps out UV rays and is waterproof and, being somewhat breathable, allows air to circulate and prevent mildew and dry rot from forming on the vehicle.