Depending on the product selected required headroom for a standard installation is typically between 12 and 18 inches. So, if you are using a door that is seven feet high the typical minimum ceiling height would be eight feet, leaving twelve inches of headroom.

Yes, an 8-foot garage door is wide enough for a single-car garage. Standard, single-car garage door widths start at 8′ for single-car garages and increase in 2″ increments to 20′ wide. Double car garage doors typically start at 12′ wide and increase in 24″ increments to 18′ wide.

Single Garage Doors Less Common Garage Door Sizes: Garage doors with heights ranging from 9 to 12 feet are less common but are available.

Normal Thickness: Typically, garage doors are between half an inch to 1 inch thick. This is thick enough to provide some separation between you and the external environment. However, in the end, it's only a small sheet of material. Thus, it tends to be susceptible to dents.