2006-10-13 09:00:11 · 9 answers · asked by big dog 1 in Home & Garden ➔ Do It Yourself (DIY)
Measure the rise and run using a framing square.
Go in your attic, or find a rafter tail on the eaves at least 24" long.
Align the short leg of the square vertically to a rafter, and use your eye to establish a rough level line on the long leg of the squar (or use a 9" torpedo level.)
The vertical dimension is the rise, and the horizontal dim. is the run.
Common roof pitches are 4 in 12 (rise = 4, run = 12), 5:12, 6:12, all the way to 12:12 (a 45 degree pitch.)
2006-10-13 10:17:42 · answer #1 · answered by Tom-SJ 6 · 0⤊ 0⤋
THe pitch of a roof is determined by the rise and the run. So basically for every twelve inches up you have 4 inches of run then it is a 12/4 pitch. That is a very small pitch. If you have a 12/12 it is a steep pitch.
2006-10-13 09:03:06 · answer #2 · answered by moussesdad 2 · 0⤊ 0⤋
The pitch is based on how much the roof rises in one foot. You can use a Framing Square to lay out or calculate the pitch. If you are making your own roof components you will need a good framing square anyway. The framing square will be important should you need to cut "Bird Mouths" in the roof rafters. The bird mouth cut is necessary to provide a good base for the rafter where it sits on top of the wall. Look here for an explanation and a sketch of a Seat Cut or bird mouth.
http://daveosborne.com/dave/glossary/glossary.php#seatcut
Most roofing shingles are manufactured to be installed on a minimum of a 4 on 12 (or better) pitch.
If you are designing and planning to build you need to know what type of shingles you are going to use so you can plan for the proper pitch and structure to support the weight.
2006-10-13 09:36:32 · answer #3 · answered by Tim Taylor 3 · 0⤊ 0⤋
you can buy a pitch indicator at homedepot or lowes. simply lay it on the roof and it will tell you the pitch/angle. or measure one foot back from the front edge of the fascia then measure up to the top of the roof. if you measure 8" then you have a 8/12. if you measure 6" then the pitch is 6/12
2006-10-13 13:02:49 · answer #4 · answered by mr.dj 3 · 0⤊ 0⤋
use trigonometry if you need to build yours measure
a sq +b sq = c squared.
sorry cant figure how to type that on here but get an old math book out ..
yes tell the kids there is a reason for math in school!
a is the height from bottom to top of roof right down the middle , straight line up
there are two triangles to make the 90 degree angle..
and b is the width from roof to roof ends at bottom.
use a calculator a and square add to b and square and get c squared so unsquare it.( v---) button looks kind like that. but solid no spaces ..
rise is height up the middle and run is half length of total roof at bottom.
got to get up a ladder and measure either way..
2006-10-13 10:15:34 · answer #5 · answered by macdoodle 5 · 0⤊ 0⤋
find the length and the height. I think its A squared plus B squared= C squared. If its 12 inches long and 4 inches high its a 4/12 pitch
2006-10-13 09:07:52 · answer #6 · answered by kn1 1 · 0⤊ 0⤋
Climb up on the roof, right to the peak and lay down lengthwise. Now let urself roll right off the roof.
If you only got the wind knocked out pitch is 8 - 12%
If you suffered severe bruises and contusions pitch is 12 - 18%
If you broke 4 or more ribs and shattered your pelvis pitch is 18 - 22%
If your dead pitch is greater than 22%
2006-10-13 09:04:16 · answer #7 · answered by stevekc43 4 · 2⤊ 2⤋
Go to lowes, ask them for a speed square. A cheap one is about $5. Ask him how to use it to determine roof pitch. You won't believe how easy it is. And everyone thinks it is so hard
2006-10-13 13:04:14 · answer #8 · answered by B 2 · 0⤊ 0⤋
6/12 - 1 RISE/2 RUN
A 12' RAFTER WILL RISE 6'
2006-10-13 09:05:09 · answer #9 · answered by Bonno 6 · 0⤊ 0⤋