Standard pitch of roof in degrees, ratio & fraction for house | standard roof pitch | standard roof pitch for shed, house, metal building, pole barn, warehouse, snow load, metal roof, ranch house, concrete tiles, gazebo, asphalt shingles | what is standard roof pitch.
Pitch of roof is the measurement of roof’s slope expressed in ratio, fraction, percentage and in degrees, there is no one single standard for pitch of the roof used on all sloped roofs, determining factors such as roofing material and local climate condition help to determining the appropriate range of the pitch for a given building or structure.
In earlier time from the beginning of civilization peoples are always looking for house which built by timber covered with roof to prevent from heavy rainfall and snowfall conditions. Design and construction of roof is depending on many factors but one of the most common important factor is climatic and weather condition of your surrounding areas, in your cities and countries.
The area which has heavy rainfall and snowfall require good drainage for roof, roof drainage depending on slope of the roof provided, based on slope of roof it is categorised into two types flat roof and pitched roof or sloping roof. These are two types of roof structure based on slop.
Flat roof is type of roof in which slope is generally less than 10°, which only enable to ensure adequate drainage of rainwater in low to moderate rainfall regions. Pitched roof is type of roof comprising sloping surface or surface with an angle of usually over 20°, generally it slopes downward in one two or more parts depending on design and construction.
Standard pitch of roof in degrees, ratio & fraction for house
Pitch of roof lower than 4/12 have a slight angle called as low slope roof, pitches of less than 2/12 considered as flat roofs, pitches higher than 9/12 are called as steep slope roofs, pitches ranging between 4/12 to 9/12 is considered as conventional roofs pitch suitable for most of residential house.
Standard roof pitch:- most commonly standard pitch of roof falls in range between fraction of 4/12 and 9/12, in ratio of 4:12 to 9:12, in degrees of 20° to 40° angle, or in percentage of 25% to 75% used for house, shed, warehouse, workshop, godowns, garage or metal building as per roofing material and climatic condition in snowfall & heavy rainfall areas or countries such as Canada, Northern Europe, United kingdom, Australia, New Zealand, United State etc. This is normal, average & standard size of pitch of roof suitable for conventional structure.
Roofing material deciding the pitch of roof, roof with extreme pitch either low or steep are inappropriate for certain roofing material. Flat roof or low slope roofs should not be roofed with Asphalt shingles or concrete tiles, these roofing materials are appropriate for roofs with conventional pitches between 4/12 to 9/12. Roofing material that work well on flat or low slope roof such as tar and gravel or rubber membrane should not be used for conventional or steep slope roofs because their installation create a problem and unattractive materials are very visible on highly angle steep roof.
Environmental and climatic condition also rules the roof pitch. In area such as Canada Northern Europe as snow accumulation is heavy, low slope roof can make problem because excessive build up snow can become so heavy that roof fails. Higher steeped roof also create problem as snow is likely to slide down to eaves, it can damage to roof and danger for people below from falling ice & snow.
In cyclone prone area roof problem can be worse, if the roof frames do not have a required bracing and support structure are not properly safe, they can collapse, or either peel away by wind and much of overhang pitch roof can be uplifted by wind causes roof to detach from the external walls.
Standard roof pitch UK
In United Kingdom and in Northern Europe, with its often wet & windy climatic condition, generally standard pitch of roof will be roughly anywhere between degrees of 30°-50° angle but at the extreme can go up to 70°, if it is expressed in ratio, then it will be range between 7:12 to 14:12 or in fraction 7/12 to 14/12 or in percentage 60% to 120%. This is good range for roofs pitches in the UK generally used for residential house, shed, workshop, garage, gazebo, warehouse, snow load, ranch house, pole barn house etc.
Standard roof pitch Canada
In some areas building code require a minimum slope, in Canada, with its often wet, snowfall & windy climatic condition, generally standard pitch of roof will be 26.6° angle but at the extreme can go up to 50°, if it is expressed in ratio, then it will be 6:12 or in fraction 6/12 or in percentage 50%. This is good range for roofs pitches in Canada generally used for residential house, shed, workshop, garage, gazebo, warehouse, snow load, ranch house, pole barn house etc.
Standard roof pitch Australia
Slope of roof rules by Building Code, in Australia, standard pitch of roof are range between 15° to 22.5° depending on roofing material. This is good range for roofs pitches in Australia in which roof pitch and their panel angle able to clean self in the rain. As per thumb rule most suitable roof pitch angle is 12° for Darwin, 27° for Brisbane, 31° for Perth, 34° for Sydney and etc.
Standard roof pitch New Zealand
In New Zealand, standard pitch of roof is usually in the range of 4/12 to 6/12 or 20 to 25 degrees for conventional structure, lower than 4/12 used for low slop roof, below 2/12 for flat roof and higher than 9/12 generally used for steep pitch roof. They are also follow the Australian building code for pitch roof design.
Standard roof pitch India
In India, most common, standard pitch of roof is usually 25° angle or 6/12 used for conventional structure such as house, garage, shed, godowns, etc. Roofing material is major factor that deciding the design of roof, so it even goes to 33° to 45° angle. Traditionally most of the house in India have low pitch or flat roof which is only 1/12 to 4/12 slope.
Standard roof pitch USA
In United States, the most common standard pitch of roof are falls in the range between 4/12 to 9/12 or 20° to 37° for conventional structure such as house, garage, shed, godowns. If your building is in area with heavy snowfall then steep roof higher than 9/12 are preferred to avoid the snow build up onto roof and areas with heavy rainfall still avoid to use flat roof. A gable or hip pitch roof may be perfect, they can easily shed water and allow for more ventilation.