I am building a two story house that is 24′ wide x 30′ deep. The plan is to build an 8′ porch running across the front of the house that connects to a 10′ porch that runs down the side. I would like to have a shed roof that covers the front porch, turns the corner and runs down the side. My framer is having trouble with the hip section of the roof (turning the corner) since one side of the porch is 8′ and the other is 10′. Could someone explain how to frame this ? Starting next week, so I need info fast. Thanks for your expertise.
Jcrew2
Replies
Did the plans come with framing detail?
Mark
Do you want the same overhang and if so what is the overhag so that I can give you the hip offset?
Does the plans show a pitch for either the front or the side roof.
I assume that the front is 24' and that's where the 8' porch is running.
Joe Carola
Edited 7/9/2005 9:49 pm ET by Framer
Joe,
You in Huston Lumber in Oldwick on Thursday?
Yes I was. Where were you?Joe Carola
Thought I recognized the name on the truck from somewhere. Yeah, I've been out of business since I went back on Active duty late in '01 but I've still got an account there.
A triangle created by the hip line would have one leg of 10' and another leg at 8'. Using Pythagoran theorem I can figure the hypotenuse to be 153-11/16'' light. This is the amount of level run on the hip. Take the total amount of rise in inches say 3/12 on the common rafter. This converts to 30 inches over the ten feet, which means on the adjacent roof the rise will be 30 inches over eight feet. Now we can take 30 inches of rise and 153.675 run of the hip and divide by a common number, say 10 and this should give us something to hold on the framing square. The hip cut is basically 3 in 15-3/8 light. Using the theory to figure the length of the hip rafter is 153.675^2+30^2=hyp. Hyp is 156-9/16 inches light.
We can figure the common on the eight foot side the same way. In this case 96 inches of run and the 30 inches of total rise divided by ten is 9.6 or 9-5/8 so 3 in 9-5/8 light on the square. Figure the length of the eight foot common. 96^2 + 30^2= hyp. Length of common on the eight foot side is 100.578 or about 100-9/16 inches.
I'm sure there are other ways to go about this but, this is the way I would build it. Hopefully this approach is not too confusing. Maybe you'll get an easier method suggested.
Maybe a trig wiz will come by and give you the side cuts. If not mark an 8/10 on a board with the framing square and measure the angle with your speed square. That should get you close enough for carpentry.
Edit I just read Joes post and thought of a reminder: keep in mind that your over hang will be different, the 10 foot side being longer. And also remember that my rafter length calculations are in regard to a specific run so over hangs will have to be figured. I would leave the tails run wild and where the planes meet make the plumb cuts in place. And also obviously I just guessed at the rise for the purpose of example.
Edited 7/9/2005 9:44 pm ET by quicksilver
Edited 7/9/2005 9:54 pm ET by quicksilver
WHAT!............... I'm joking, well said quicksilver
Mark
You scared me for a second. . . . thankyou
There are no plans for the porch, these are on site changes. The 24ft side is where the 8' porch is. I want a pitch of either 4/12 or 6/12 with 18" to 24" of overhang. I guess I would prefer the overhang to be even on both sides but I am flexible. Whatever looks best.
Edited 7/9/2005 10:36 pm ET by jcrew2
Edited 7/9/2005 10:39 pm ET by jcrew2
The roof can be done anyway you want but you have to be more specific. If you do what Bryan said and keep the same pitch then the 10' side would be higher by 8" using a 4/12 pitch and your hips will be running @ 45° and sitting on the corner with all the same overhangs. That can cause problems with windows on the second floor if they're all the same height and you might not like the way the side roof loks being higher than the front roof. But it makes cutting all the rafters a lot easierIf you want the tops the same and the same overhang then you will have different pitches on the front and the side and your hip will not sit on the corner and will not be running @ 45° it will offset towards the steeper pitched side which in your case will be the front which would be a "Bastard Hip" and you would have to adjust your plate height or your HAP/Heel cuts.If you want the hip to sit on the corner then you will still have different pitches and the hip will still not sit @ 45° and your overhangs wont be the same and still have a "Bastard Hip". The overhang will be shorter on the steeper side using the same HAP/Heel cuts. That can look bad if your running beadboard or something for a soffit.If you do what Bryan said just tell us the pitch and overhang length.If you do one of the other two tell us the same thing.You have to take in cocideration what the ceiling of the porch will be also. Will you have ceiling beams?If you dont have ceiling beams and your keeping it cathedral and you put beadboard or something on the ceiling than Bryans way would be the best because the hips are sitting on the corners and running @ 45° and also your jack rafters. That makes it nice for all your cuts when you put your ceiling on the angles at the hip will be the same on both sides so they will line up perfectly.If you have a cathedral ceiling using two different pitches with a "Bastard Hip" when you run the cuts up the hip you will have teo different angles and all your miters wont line up.Joe Carola
On the square the short side would be 4 inches rise for 9.6 inches travel, meaning the over hang for a level soffit would be 2.4 inches different per foot. Framer is right about the ceiling, you will not be able to run bead board and have a moulding line match, but aesthetically from the outside I think an even peak against the house, a plain soffit, a wrapped header beam, and if you wanted the bead board, a stop running the underside of the hip to visually break the line would probably be easiest. If you follow the math, cut two commons for each pitch and the hip all should come clear. To me two different ledger lines or a "jumped joint" on the hip would look more awkward, in my opinion the difference in overhang would create the most eye pleasing solution.Edited 7/10/2005 12:28 am ET by quicksilverEdited 7/10/2005 12:41 am ET by quicksilverEdited 7/10/2005 9:05 am ET by quicksilver
Edited 7/10/2005 9:52 am ET by quicksilver
This is one way with the Construction Master to get most of the measurements he needs for equal overhangs and a 4/12 front with an 8' run and the side with a 10' run.I always include my overhangs in because it causes less confusion and sets the hip exactly where it should be.Front 8' + 1'6" = 9'6" (Run)
Side 10' + 1'6" = 11'6" (Run)4 [Inch] [Pitch]9 [Feet] 6 [Run][Diag] Returns - 10' 3/16" (Common Length Front Rafter)[Rise] = [Rise] Returns - 3'2" (Rise)11 [Feet] 6 [Run][Diag] Returns - 11'11-1/8" (Common Length Side Rafter)[Pitch] Returns - 3-5/16" (Pitch of Side Rafter) 4 [Inch] [Conv] [Hip/V] [Hip/V] Returns - 15'3" (Hip Length)[Hip/V] Returns - 11.99° (Hip Plumbcut Angle)[Hip/V] Returns - 78.01° (Hip Level Seatcut Angle)[Hip/V] Returns - 39.56° (Hip Angle in plan View and Cheek Cuts 4/12 pitch side)[Hip/V] Returns - 50.44° (Hip Angle in Plan View and Cheek cuts 3-5/16 pitch side)[=] [Pitch]1 [Feet] 6 [Run][Rise] Returns = 1'9-3/16" [-] 1 [feet] 6 [=] 3-13/16" (Hip Offset)If you wanted to just get the Hip in Plan View Angle you can just do this.Tan-¹ (9'6" / 11'6") = 39.56° (Steeper Pitch Side)Tan-¹ (11'6" / 9'6") = 50.44° (Lower Pitch Side)Joe Carola
Edited 7/10/2005 1:42 am ET by Framer
Hey Joe the last time we talked a bout the Construction Master you well convinced me and I was wishing I had one last night when I started messing with this problem. I really need to order one.. That thing is is great and I can't believe I got this far without one.On the brighter side of the coin,I had an impromptu meeting with the owner of our company, who is always grilling me about times and dates and what was said exactly when contacts with subs take a bad turn. So I told him I wanted a Blackberry. He said no problem. With lasers, range meter the Const. Master, and A Blackberry I'll be turning into a robot.ps I still haven't decided about the range meter. But I got a demo and it had more positives than negatives.
You can keep the same pitch and the same overhang. The 10' side will be 8" higher on the wall where it meets the house at a 4/12 pitch, and the hip will be 2' from the corner on the 10' side.
Now, if you want the roof to be at the same line on both sides of the house, then see the previous responses.
Bryan
"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio
jcrew2,
If your framer is having trouble with this then he is probably gonna have trouble with some of the explinations you got as well.
If that's the case, I would work off of the long side. I would pick the pitch and overhang I wanted and cut a handful of rafters. Dummy up the roof and then transfer the top line around the corner and down the short side. Make sure you clear all the windows and such. If you do, you can use a few blocks tacked in place and a string line to figure out the pitch and the rafter lenght and seat cuts and such.
Next draw the overhang and corner at full scale on the floor or a few sheets of plywood tacked down. That will give you a chance to catch any mistakes.
The hip will be bastard and you can lay it out on some plywood as well.
I can do the math but a lot of people can't and I long ago got tired of trying to teach it so I just started showing guys the Fischer Price method described above.
Maybe you'll be luck and your framer will understand it.
I really want to thank all of you for your help. This forum is the best. I asked for info fast and you guys jumped right in. I appreciate all the responses I've gotten so far. Keep them coming. Everytime I've needed help, this is where I come and you guys always come thru. Just wanted to say thanks. I'd buy you all a beer if this site had a bar !
Jcrew2
Ok, lets say I want a 4/12 pitch for the front (8') section, and I want the roof of the porch to line up even on both sides of the outside walls. 6/12 would be okay but it may be cutting it close when it comes to the upstairs windows, but that is not a problem on the side section of the porch, just on the front. The overhang can be different on each side if need be. I just want at least 18", and 24" is fine. I plan to have ceiling joists and use bead board or plywood for the ceiling material so it will not be cathedral.
Jcrew2
I think you should install your posts and beams and ridge first, then figure your actual rise and run from that. If your framer has trouble visualizing what the hip will be, cutting the commons for each side and figuring where the sub facia will be may help him. At least then you will have some actual numbers for Framer to punch in his construction calculator. I am assuming you want top, beam, and sub facia on same plane around house.
Here are some numbers Common on 10’ side discounting overhang 126-1/2’’ 4 / 12 pitchcommon on the 8’ side discounting overhang 104''' 4 / 9.6 or 4 / 9-7/16 pitchhip length if the hip sets on the corner of the house and the outside corner of the roof discounting overhang 153.675 or 153-11/16. 4 / 15-3/8 pitchUse Roberts advice as far as comfort in figuring the rafter tail.Use these numbers as a check, or build with them, but on some thing like this it is best to do some prepping and mocking up to work out the quirks especially if your guy doesn’t have experience with this sort of thing. Your bead board ceiling is not going to be able to run corner to corner even if it is level and get the beads to line up maybe jumping the joint off the corner of the house to 45-degrees below would solve the ‘bastard’ of a scenario best using one technique above and another below.It's elementary, but a reminder to make sure from rake angle to seat cut is equal on all three members
Dagnabit!
Since there are no plans - Make both porches the same width and get on with it!
Ouch,...I don't know who is more confusing..... The guy with the vague problem, or the guys with the overcomplicated solutions. I'm confused, and I do this type of $hit every day. What was the question again?....Why yes,..I would love another beer.
As far as vague I've seen more vague. As far as overcomplicated what's your simple solution to the bastard hip?
lol, get some other sucker to do it.....that is the easiest way. or maybe stringline and tape,.. just a thought.
I came up with a simple solution. Three years ago I had a similar porch job. Main porch was 10'-0 wide and the side porch was 6'-0 wide.The overhang was 12".Overhang had to be the same on both roofs.I layed it out on a piece of plywood using the framing square to a 2"=1'-0" scale.
This showed me that the hip would not fall on the corner of the post .Not having framed many hip roofs ,this got me very close to correct. I wound up tapping the hip rafter about one inch to line up the sub facias. I also had to raise the hip slightly, maybe a 1/4" or so.For me this was the easiest way, if I did these roofs often I would learn to calculate them mathematically .After reading a couple of posts on how to do this, I glad I didn't try it or I'd still be calculating.
mike
This is what I was thinking. There must be a reason for two different widths. Sounds like the classic archy dilemma with letting creativity trump practicality or even worse, common sense.
This is very common around here in NJ probably because of set backs. Most of the porches the fronts are usualy bigger than the sides. Some house the sides are facing a driveway and some houses the sides are facing no driveway.Joe Carola
figured it was something like that
Joe,
What area are you working in? I assume it's in the somerset/morris county area? How's it going in that area?