scientific /mathematical Equasion!!Pitch

2012paddy2012

:)hi guys

this is sort of related to another related post but specially I am trying to understand how you work out the pitch on an extension. Maths not best subject...could anyone tell me how its done using whatever calculation is used please. I believe my extension is 12 degrees! how is that worked out?Thanks


SEE PICTURE/SKETCH THANKS PADDY

mickdw

You need to keep all your measurement units the same so either work everything in feet or inches or mm etc.
You have the vertical rise and the horizontal travel ( the width of the extension)
Divide the rise by the horizontal distance and hit inverse tan on your calculator. So in your case 2.5 ft divided by 12.5 ft equals 0.2
Inverse tan of 0.2 equals pitch. I believe it would be something over 11 degrees.

You would need to accurately check the measurements though as overhang / wallplate positioning will possibly effect the pitch.

4Sticks

easy as a b c

2012paddy2012

mickdw wrote: »

You need to keep all your measurement units the same so either work everything in feet or inches or mm etc.
You have the vertical rise and the horizontal travel ( the width of the extension)
Divide the rise by the horizontal distance and hit inverse tan on your calculator. So in your case 2.5 ft divided by 12.5 ft equals 0.2
Inverse tan of 0.2 equals pitch. I believe it would be something over 11 degrees.

You would need to accurately check the measurements though as overhang / wallplate positioning will possibly effect the pitch.

wll do thks...I think I am definitely dealing with a bluffer !! I told builder what the pitch was approx. using this method and he tells me he used the other way that most builders use for roofs!! knowledge is power !thks

DOCARCH

2012paddy2012 wrote: »

...he tells me he used the other way that most builders use for roofs!

:P

topcatcbr

2012paddy2012 wrote: »

wll do thks...I think I am definitely dealing with a bluffer !! I told builder what the pitch was approx. using this method and he tells me he used the other way that most builders use for roofs!! knowledge is power !thks

In fairness. Most "roofers" don't use degrees. They'll use a rise. That is 1:3 or 1:12 etc. that means 1" rise for every 3" or 12". That doesn't mean he is or isn't a bluffer.

It's a lot easier onsite to use the above method.

galwaytt

topcatcbr wrote: »

In fairness. Most "roofers" don't use degrees. They'll use a rise. That is 1:3 or 1:12 etc. that means 1" rise for every 3" or 12". That doesn't mean he is or isn't a bluffer.

It's a lot easier onsite to use the above method.

Indeed - an angle finder or protractor on a site would be a novelty !! But tapes - tapes are everywhere !!