I did a quick search and found that common gambrel roof angles are 30 and 60 degrees. Starting with a piece of 1x 6 cedar. I know how to make the 30 degree cut. What reference point do you put the square to make a correct 60 degree cut.
jaime
y _ h(2) /| b( v3 / 2 ) /_| x(60) a(1)
Hokay. You want angle x to be 60 deg. Side a will be one half the length of side h. For your 30 deg angle y, side b is half the square root of 3, which, IIRC, is irrational, and not easy to measure on your ruler. Or, you can run down to the art supply store and get a 30-60-90 plastic triangle.
I'm not quite sure what you are trying to accomplish here, but I'll offer some info and hope it helps. If not, be more specific, and I can try to be more focused with the answer. Also, I'm going from memory here, so double check my figgers please. It sounds as if you are trying to make a 21/12 pitch (the 60deg) roof lead into a 7/12 pitch (the 30deg) roof . If you are using a standard carpenters square, line up the 7" mark with the edge of the board and the 12" mark with the same edge of the board. This gives the 30 deg angle (7/12 pitch). To get the "long 30" as we call it when framing, line up the 7" mark again and the 17" mark. This will give your 60. If you do not own a Swanson Speed Square, get one with the little blue instruction manual. These are one of the greatest carpenters tools ever invented and will be your greatest aid cutting the angles for any roof system. Probably around $10 and in every small hardware store/borg in the nation. --dave
On 20 Nov 2004 15:30:51 -0800, snipped-for-privacy@hotmail.com (jaime steward) calmly ranted:
Are you making the half-octagon gambrel roof or the hat-shaped gambrel roof? The hat-shaped (barns with wings) uses odd angles.
That means you make 15° cuts on each side for each complementary angle for the peak, the very top of the hat. The outside of those two boards get cut at 30° each making a 60° angle. There is no 60° cut.
For the normal half-octagon gambrel, make all cuts 30°. Fit birdsmouths on the bottom of those near-vertical sticks to the framed walls as necessary.
Perhaps you should get a set of plans. These 100 ought to help:
I made a bird feeder. I wanted a gambrel roof. I made a 45 deg roof lead into a 35 deg roof. I didn't know the right angles for the gambrel roof and I made the 45 deg mark on the edge of the wood and then cut it and then put the square at the end of the 45 deg cut and found 35 deg. and cut that. Next time I will mark both angles from the edge of the wood. Starting with 60 deg leading into a 30 deg roof.
Jaime
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.