This article is about the type of roof construction that consists of footings and an outer weatherproof skin, as found on most domestic architecture.
Such roofs may take a number of different shapes and be constructed of and covered with a variety of materials.

Construction of a ridged roof

A simple ridged roof consists of declined rafter

Rafter

A rafter is one of a series of sloped structural members , that extend from the ridge or hip to the downslope perimeter or eave, designed to support the roof deck and its associated loads.-Design:...

s that rest on vertical wall-plates on top of each wall. The top ends of the rafters meet at the horizontal ridge plate or ridge beam. Horizontal purlin

Purlin

In architecture or structural engineering or building, a purlin is a horizontal structural member in a roof. Purlins support the loads from the roof deck or sheathing and are supported by the principal rafters and/or the building walls, steel beams etc...

s are fixed to the rafters to support the roof covering. Heavier under purlin are used to support longer rafter spans. Tie beams or ceiling joists, are connected between the lower ends of opposite rafters to prevent them from spreading and forcing the walls apart. Collar beams or collar ties may be fixed higher up between opposite rafters for extra strength.

The rafters, tie beams and joists serve to transmit the weight of the roof to the walls of the building. There are a number of structural systems employed to facilitate this, including the use of wall-plates set at the top of the wall, hammer-beams, which spread the weight down the wall and create an equilibrium between outward and upward thrust, king post

King post

A king post is a central vertical supporting post used in architectural, bridge, or aircraft design applications.-Architecture:...

s which transfer the weight of the roof ridge, and various types of truss

Truss

In architecture and structural engineering, a truss is a structure comprising one or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. External forces and reactions to those forces are considered to act only at the nodes and result in...

es.

In cyclone

Cyclone

In meteorology, a cyclone is an area of closed, circular fluid motion rotating in the same direction as the Earth. This is usually characterized by inward spiraling winds that rotate anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth. Most large-scale...

 and hurricane prone areas the main engineering

Engineering

Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

 consideration is to hold the roof down during severe storms. Every component of the roof (as of course the rest of the structure) has to withstand the uplift forces of high wind speeds. This is not normally a problem in areas not prone to high wind.

Modern roofing technologies, apparent in the accompanying photo of a house under construction in a region of Northern Australia

Northern Australia

The term northern Australia is generally known to include two State and Territories, being Queensland and the Northern Territory . The part of Western Australia north of latitude 26° south—a definition widely used in law and State government policy—is also usually included...

, include the purpose-made steel hook bracket which is bolted to the truss with M16 bolt. The bracket is bolted to an M16 bolt cast in situ, embedded 300 mm into the reinforced concrete

Reinforced concrete

Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...

 block wall. This system is typically in place every 900 mm around perimeter

Perimeter

A perimeter is a path that surrounds an area. The word comes from the Greek peri and meter . The term may be used either for the path or its length - it can be thought of as the length of the outline of a shape. The perimeter of a circular area is called circumference.- Practical uses :Calculating...

See also

• List of commercially available roofing material
• List of roof shapes
• Interior protection
  Interior protection
  Interior protection is the general term for the installation of temporary dust and debris containment systems during re-roofing, remodeling, or other construction related projects. A temporary interior protection system can be installed in almost any environment, from manufacturing plants,...
  
  
• Roof garden
  Roof garden
  A roof garden is any garden on the roof of a building. Besides the decorative benefit, roof plantings may provide food, temperature control, hydrological benefits, architectural enhancement, habitats or corridors for wildlife, and recreational opportunities....
  
  
• Tented roof
  Tented roof
  A tented roof is a type of roof widely used in 16th and 17th century Russian architecture for churches. It is like a polygonal spire but differs in purpose in that it is typically used to roof the main internal space of a church, rather than an auxiliary structure...
  
  
• Cool Roof
  Cool roof
  Cool roofs are the roofs that can deliver high solar reflectance and high thermal emittance...
  
  
• Building construction
• Building envelope
  Building envelope
  The building envelope is the physical separator between the interior and the exterior environments of a building. Another emerging term is "Building Enclosure". It serves as the outer shell to help maintain the indoor environment and facilitate its climate control...
  
  
• Green roof
  Green roof
  A green roof is a roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage and irrigation systems...
  
  
• Metal roof
  Metal roof
  A metal roof, often referred to as a tin roof, is a roofing system made from metal pieces or tiles. It is a component of the building envelope.-History:...
  
  
• Metal Roofing Alliance
  Metal Roofing Alliance
  The Metal Roofing Alliance was formed in 1998 by a group of metal roofing manufacturers with the main goal of educating consumers about the benefits of metal roofing...
  
  
• Roofer
  Roofer
  A roofer specializes in roof construction, concentrating on the application of materials that water proof and / or weather proof buildings,designed material—as a substrate for the roofing materials to be installed on. The rafters, beams, and trusses are the frame or skeleton for the roof to be...
  
  
• Roofing felt
• Tensile architecture
• Thin-shell structure
  Thin-shell structure
  Thin-shell structures are light weight constructions using shell elements. These elements are typically curved and are assembled to large structures...
  
  
• Tile
  Tile
  A tile is a manufactured piece of hard-wearing material such as ceramic, stone, metal, or even glass. Tiles are generally used for covering roofs, floors, walls, showers, or other objects such as tabletops...
  
  

External links

• An Illustrated glossary of roofs and roofing terms.