roof pitch

2012paddy2012

Hi does anyone know how to work out (in ordinary language!) the roof pitch of an extension.

I have an extension at the moment and I think that the pitch is too low and that may be causing a leak.

I can easily measure the length of the building and the width and the dimensions of the extension.

If some one can give me a basic calculation I would be very obliged.


Many thanks

Paddy

Supertech

You'll need a scientific calculator (or at least one that will do basic trigonometry) or log tables.
Obviously all of your measurements will need to be taken outside unless you have a sloped ceiling in the extension.

a) Measure the height of the wall at the highest point of the roof and and the height at the lowest point.
b) Measure the length between the highest and lowest points horizontally along the wall.
c) Subtract the smaller of the two heights from the larger to give you the overall rise of the roof.
d) Then divide this rise by the length of the wall (ans c divided by ans b)

This is the tangent (tan) of the roof angle or pitch.
The cotangent of this answer is the angle of the roof. You'll get this by pressing the tan-1 button on your calculator or by looking up the nearest value in your log tables.

Guest0000

Try the link below, by tracing a level line from the tail of the bottom tile at the gutter, to the back wall of the house, and then measure the height to the tile above at the lead flashing, and measure the length of the extension back to the tail of the tile,
Input the lengths in to the diagram below.....
http://www.csgnetwork.com/righttricalc.html