I am trying to get all this together about Hip Roofs, there is so many different ways it can be done. I just have QUESTIONS????
I always thought that the first thing you do is subtract the width from the length to get the length of the ridge, but do I need to add 1 1/2 inches to the overall length of the ridge? Some articles I read says nothing about it and some say add the 1 1/2″ to it.
If I add this extra 3/4″ to both ends, I guess then I will reduce the end of my 2 common rafter that tie into the ends of my ridge by 3/4″ to match all other common rafters that are tied into the ridge? This makes since.
Then do I need to lay off my top plate starting with the center and going 16″ OC until I get to the last common that stops at the end of the ridge and it might be less than 16″ OC. Then my first hip jack will be 16″ OC from my last common rafter that was on 16″ OC? Then how do you find the length of my first hip jack? I know after I get this first length that I find the next one by reducing it by the common difference of my roof pitch. I guess if you do it this way both ends will be laid out the same.
OR
Do I just start out one end and go my 15 1/4 and then start my 16 OC? If I start like this I will know what my first hip jack will be by the common difference and then I will just have to continune to add this common difference to find all my hip jacks, but when I get to the other side just past my last common rafter I will be in the same situation that I was in when I laid it off starting in the middle and going out?
Like I said there is different ways to do it and I know that both will work, but I would just like to get it in my head which way would be the best.
The other questions that I had was about dropping the hips. I think I understand the amount that you cut from the seat. I read on Joe Fusco web site and he told how to use the triangle of the roof pitch to figure the amount to take out. I think that it will usually avg. about 3/8″ out of the seat. All this does is drops the hip so the edges of the rafter line up with my common rafters, but do I take this out of all my hip jacks?
I am not sure about reducing the length by 1/2 of 45 degree angle of my end cut. Which I think I figured out that I will reduce the size by about 1 1/8″ and then make my double cheek cuts at that point. Is that correct or am I falling off the roof?
Any insite on this subject would be appreciated. I would rather ask questions and learn how to do it the right way, first.
I hope I made since of what I was trying to say. I think this actually helped me just writing this down to get it into my head.
Thanks, Jay
Replies
Make yourself some careful scale drawings.
hand cut hip roof
Regarding your question I actually had to refer back to my school book, since I never use this method in the field, your ridge board for a hip roof is equal to the length of the building minus the span of the building. The idea is to create square box from the end of the ridge to the edge house, with the hip rafter making it into a right angle triangle. From there it comes down to working point ( center of rafter) your hip starts out with butting into your common rafters, hence you would shorten your hip half of the diagonal thickness of your common.
Framing Hip Roofs
You might try posting this question under construction techniques. I'm sure you'll get more responses.
Or visit the JLC rough framing forum. There is a lot to read about Hip Roof Framing archived over at thier site too.
This is a SketchUp demo I did a couple years back about Hip Roofs.
This method works for all Hip Roofs, Regular (equal, or single pitches) or Irregular (unequal, or dual pitches). Also, following the marking and cutting directions as explained in the demo for the Hip and Valley will eliminate any concerns about "Dropping the Hip" to plane. They are both marked the same length but the cheek cut bevels are reversed, or mirrored to create the proper HAP Heel cuts on the two different rafters. The apparent proportional offset for the irregular H/V rafters is also automatically accounted for.
I hope this helps.