Propper Roof Pitch
To measure the roof pitch you ll need an 18 or 24 inch level a tape measure and a pencil.
Propper roof pitch. Mineral surfaced roll roofing requires a minimum roof pitch of 1 12 or greater. You could also opt for a pvc flat roofing membrane. Metal roof shingles require a minimum roof pitch of 3 12 or greater. The pitch of a roof is arrived at by dividing the vertical rise and its horizontal span or what people in the roofing industry would refer to as the slope.
Roof pitch in layman s language simply refers to the steepness of the roof. A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch. There are different kinds of roofs and all these have particular specifications for their installation. There are several variables to consider when determining the proper rafter size.
So let s say a roof rises 6 inches for every 12 inches in depth towards the peak. This sizing guide for roof rafters will help determine what you need for your small project. This means that the rise of the slope goes up or down 8 inches for every 12 inches. The pitch of your roof is determined by the measurement of the vertical rise by the horizontal run.
The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7. There is no standard universal roof pitch. Slate and slate type shingles require a minimum roof pitch of 4 12 or greater. There are some standing seam metal roofing options available from atas and other manufacturers that can be installed on a roof with pitch of 1 12.
An example for a steep sloped roof is 8 12. That is to say the roof pitch expressed as a ratio tells you how many inches the roof rises for every 12 inches of depth. Here s an easy safe way to determine the pitch from inside your attic. To put it in perspective the angle of this slope would be around 30 degrees.
Roof pitch varies depending on culture climate style and available materials. In the uk the typical house has a pitch between 40 50 although 45 should be avoided. Contemporary houses often have flat roofs which shouldn t be completely flat but should be around 1 40. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.
Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level. Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater. First measure 12 inches from one end of the level and make a mark. The roof pitch is important in determining the appropriate installation method and how much roofing material will be needed.
In the usa the range of standard pitches is anywhere between 4 12 and 9 12. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.