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does anyone have a opinion about my question relating to the unequal pitched cottage end I posted last night? I am slowly putting the roof up but the trial and error is not the way to go.
p.s. my question was how do you determine the placement of the last two common rafters of the major roof. Also if the pitch of the major roof is 8/12 and the pitch of the minor roof is 12/12 what would the pitch be of the hip? 8/12 I think.
Regards and thanks, Bill Sallustio.
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Bill, My hip framing skills may be a little rusty, however I do belive You could determine the placement of the last two common rafters of the major roof by simply measuring from the ridge to the wall height (or the total rise) that number would be how far in the minor roof rafters and hips would start. as far as the pitch of the hip rafters they would be what I've heard reffered to as a "bastard hip" I'm uncertain on that score. hip roofs aren't popular in my area and I've only done two or three of the type you describe. by the way when I say total rise thats to the top of the ridge.
*bill with a 12/12 going into an 8/12 the run on the 12/12 side should be apprximately 2/3rds the run at your main 8/12 section.As far as your hip pitch,I don't know the formula,I usually use the string level and framing square method.Hope this helps.jim
* bill,
Joseph Fusco View Image© 1999."It is better to be feared. . . Then loved!" Machiavelli
*Bill,Jim answered one of your questions fairly well, the one regarding the location of the last common rafters.Let's assume the span of the "major roof", as you refer to it, is 30 feet. The half span of the roof, is 1/2 of 30', or 15 feet. Multiply this by the ratio of the roof pitches, 8/12, to find the location of the end rafters.15' X 8/12 = 10'The increase in ridge board length for this combination of roof pitches is 8/12 X 3/4" = 1/2", not 3/4" (providing that all of the rafters, as well as the ridge board is 1 1/2" thick), at each end of the ridge board. What this means is that the centerlines of the hip rafters, intersect at a point that is 1/2" in from the end of the ridge board.So, hook your tape on the corner of the wall and measure over 10 feet, for this example, and then move BACK 1/2" towards the corner to get the layout for the end rafter. Put the "X" for the layout of the rafter on the side of this mark that is away from the corner, not towards the corner.Your span is undoubtedly different, but follow the same procedure for your span, and it will work out for you.The pitch of the hip rafter, or any valley rafters, that may also be involved is 12 3/16" on the tongue of the framing square, and 22" on the body, or blade, of the framing square. If you like to use an angle square to cut rafters, this is equivalent to an angle of 29 degrees for the plumb cut.Forget about the number 17 when you cut hips or valleys for a split pitch roof. It plays no part and has no significance other than being just another number.The bevel to cut the 12/12 jack rafters is 33 3/4 degrees, and the bevel to cut the 8/12 jack rafters is 56 1/4 degrees. Cut these same bevels at the top of the hip rafters for them to fit properly, instead of putting a 45 degree cut on both sides, which will never work when two different pitches are involved. If you are using typical stock that is 1 1/2 inches wide, drop the hip about 3/8" as it crosses the corners of the walls., so the edges of the hip will plane in with the common and jack rafters. This is rather quick, but is accurate information that will help you at this point in time. I frame these type of roofs on a regular basis.If you have more questions, post them, and good luck.Ken
* bill,
Joseph Fusco View Image© 1999."It is better to be feared. . . Then loved!" Machiavelli
* Ken,
Joseph Fusco View Image© 1999."It is better to be feared. . . Then loved!" Machiavelli
*Buy a man a fish and you feed him for a day. Teach a man to fish and you feed him his whole life.I'd rather have the lesson.
* Ryan,
Joseph Fusco View Image© 1999."It is better to be feared. . . Then loved!" Machiavelli
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does anyone have a opinion about my question relating to the unequal pitched cottage end I posted last night? I am slowly putting the roof up but the trial and error is not the way to go.
p.s. my question was how do you determine the placement of the last two common rafters of the major roof. Also if the pitch of the major roof is 8/12 and the pitch of the minor roof is 12/12 what would the pitch be of the hip? 8/12 I think.
Regards and thanks, Bill Sallustio.