A mansard or mansard roof (also called a French roof) is a four-sided gambrel-style hip roof characterized by two slopes on each of its sides with the lower slope at a steeper angle than the upper. The roof creates the maximum interior space clear of supports. This is why many hay barns use this type of roof. I liked this view (although soft) because it shows the unusual rafters configured to provide support for the double slope on each side. Visit Barn Charm for pictures of many other barns.