Dormer. A (n) framed protrusion over the roof plane. A rafter, also known as a _____________________, is a sloping structural element of a roof structure. Valley. The space between two adjacent rafters or ridge lines. Gable. The triangular-shaped section of a house roof that extends beyond the walls and between the front and back roofs. It provides an area for decoration and sometimes includes a window or door opening.
The framing around the opening serves to support the weight of any objects placed within it. If no frame is used, then this opening is called a "hole in the roof".
A dormer can be single- or double-gabled, but it usually has three sides: one facing the valley, one facing the gable, and one facing into the attic space. Dormers are commonly used on houses with high-pitched roofs to provide additional room below without increasing the overall height of the building. They also allow for the installation of windows across a greater surface area of the roof than would otherwise be possible.
Gables can be flat or peaked. The upper portion of a wall or roof that projects beyond the lower portion, which is generally considered part of the floor or ground level. This upper section may be flat, rounded, or pointed.
A rafter is one of a sequence of sloping structural parts, such as wooden beams, that reach from the ridge or hip to the wall plate, downslope perimeter, or eave and are meant to support the roof shingles, roof deck, and the loads they support. A "couple" is a pair of rafters. A "stringer" is a long beam running parallel to the roofline; it may be made of wood or steel. The word "rafter" comes from the French for 'dry stick', because when dried out, a log will split into two pieces at right angles to each other, creating four feet (1.2 m) each with two free-floating ends called "rafters".
Inc. Encyclopaedia Britannica Sloping roofs come in a variety of shapes and sizes. The lean-to, or shed, is the most basic, with simply one slope. A gable, or pitched, roof is one with two slopes that create a "A" or triangle. The third angle is created by the end wall or house itself. Tiled roofs are also considered to be gables because they have both long and steep slopes. Flat roofs are completely horizontal surfaces without any rise or fall. They can be made of asphalt or concrete, but they must be kept dry to prevent damage.
The word "gable" comes from the Old English gabben, which means "to bend." This describes the shape of the roofline when viewed from above: It has the appearance of a downward-bending "G."
In English churches, a gable is the triangular part of the roof covering the body of the church. It usually extends past the side walls at each end, forming a shelter for the altar. Gables may be simple or complex, depending on their design and material choice. Simple gables have flat or vented panels attached directly to the wood frame of the church. Complex gables often include decorative elements such as finials, pendents, and dormers. Bell towers often have complex gables to cover the bells housed inside them.
Each truss is made up of two opposing rafters as well as a ceiling joist. The rafters are compressed and pushing outward on the eaves walls, while the ceiling joists are tensioned and drawing inward on the eaves walls. This creates a counteracting force that keeps the roof from collapsing.
Trusses were first used by French architects in the late 18th century as a more efficient way to build large roofs than using single timber beams. Before trusses were invented, builders often used heavy cranes to lift huge timbers into place or they would have to use smaller trees instead which would be expensive and difficult to find on site. Trusses allow builders to use much thinner timber than would otherwise be possible because it doesn't have to support so much weight. Also, since there are no longer any major supports under the middle of the roof, it can be made out of very thin material which reduces the amount of material needed for its construction.
Today, trusses are still used in many large-scale building projects such as stadiums, but they also appear in small buildings such as churches when roofing material needs to be replaced or repaired without having to replace the entire roof.
The type of truss used in a structure depends on how much load it has to carry as well as what kind of material it's made out of.