With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs.
Standard roof pitch for residential.
Roof pitches exceeding the level of 9 12 or approximately 37 degrees are termed steep slope roofs.
One of these measuring standards applies to the degree of slope that exists between the eaves outside edges of the roof and the ridge top most center of the roof.
But since there is still a wide variety of slate roofing systems there are occasions when the minimum pitch can go down to as low as 15 0 depending on the uniqueness of the roof.
The degree of slope is expressed as the pitch of the roof and a hip roof generally has a common pitch.
When it is called four and twelve roofs that mean a roof that rises four inches each twelve level inches.
Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled.
Some of the most common roof pitch types are conventional slope type roofs designed with pitch ranging from 4 12 to 9 12.
The most commonly used roof pitches fall in a range between 4 12 and 9 12.
If we consider the commercial applications then low sloop type roofs are preferred with pitch ranging from 2 12 to 4 12.
Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
The roof of your home is built to specific measuring standards according to the type of roof that is used.
These are utilized in residential applications.
The amount of vertical climb has for every twelve inches of lateral dimension by which roof pitches are represented.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
If a roof increases in height by four inches for every foot of horizontal run it is considered to have a 4 in 12 pitch or just a 4 pitch talk in terms of pitches and you will always be understood in the roofing universe.
Minimum roof pitch for shingles.
So the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally.