How do you figure roof pitch?

[bluefish]

I should know this! How do you figure out the roof pitch of a roof that's already there?

Thanks!

[watcher]

A level and a ruler is all you need. Make a mark 12" from one end of the level, place that end of the level on the roof. Get it level and measure from the roof to the level at the mark. That's the number of inches of rise/fall per foot.

[HMAN]

Rise and run

just put a level on the house or roof for every foot of run you will have "x" amount of inches rise.

Example 12" run / 6" rise = a 6/12 pitch

[bluefish]

Thanks guys!!!!

[Cabin Fever]

I just place a steel carpernters square (ie, 16" x 24" L-shaped ruler) up to the roof line or eave line. With the bottom of the square horizontal and level, place the 12" mark on the horizontal part of the square on the roof line, then read the inch mark where the vertical part of the square contacts the roof. If the vertical part touches the roof line at 6", you have a 6/12 pitch.

[motdaugrnds]

well, we are not professional carpenters; yet have put up every single roof on our homestead. We knew nothing about pitch of a roof; just knew it needed to slop enough for the ice to slide off as it thawed in bad weather. If our roofs are pitched accurately, I have no doubt it was by accident. Yet, all have worked well for over 18 yrs.

If you can do as suggested by the ones telling you what to do in here, then I certainly would. If you don't get it perfect, just know it will work anyway as long as the ice will slide during bad weather.

[fordy]

Originally Posted by thermopkt

I should know this! How do you figure out the roof pitch of a roof that's already there?

Thanks!

............It's just a simple ratio , so for a 3/12 pitch , just visualize a 2x4 placed vertically at the midpoint between 2 supporting , outer walls ! Now , for every inch you move UP the 2x4 vertically , you will move out , 3 inches horizontially ! fordy

[watcher]

Originally Posted by motdaugrnds

well, we are not professional carpenters; yet have put up every single roof on our homestead. We knew nothing about pitch of a roof; just knew it needed to slop enough for the ice to slide off as it thawed in bad weather. If our roofs are pitched accurately, I have no doubt it was by accident. Yet, all have worked well for over 18 yrs.

If you can do as suggested by the ones telling you what to do in here, then I certainly would. If you don't get it perfect, just know it will work anyway as long as the ice will slide during bad weather.

Snow isn't the only thing to worry about, there's the wind. If a roof is to flat it acts like an airfoil meaning high winds can suck the roof off the building. But if the roof is too steep it acts as barrier meaning the wind can push the roof/building down/over.

Back when I was a kid we decided pitch on either how long the lumber we had was or how much storage space we wanted in the loft..