Now that i’m starting on my rafters is it best to let the tails run long and cut to size after they are all up?
Thanks
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What I've found for us, is that the longer the rafters, the more likely we'll trim the tails. On smaller shed roofs, that isn't the case.
We cut our tails to length before we install the rafters and then after everything is up and nailed, ridge is straight, and the blocking is in, we run a dryline and mark the tails and cut them. Rarely snap a line.
Run long and cut, always.
You must not have much wind.
Me or the area :-)??
I know you are windy. I'm thinking about that dryline blowing in the wind though. Back in MI, it was usually so windy that it would blow a laser line at least 1/4" in the middle.
That's what I figured. ;-)
kinda depends - is there a fascia board going up? Soffit at the eaves? Decorative tails? If there's a fascia, then we usually run a little long, and snap line (or dry line) and cut after assembly.
CaliforniaRemodelingContractor.com
Run long it is then.
I'm with the group that cuts them to fit on the horses. It sure is easier there.If you get a wild one it can always be trimmed or shimmed after they're in place.
There are a number of mechanical devices which increase sexual arousal in women. Chief among these is the Mercedes-Benz 380SL.
Now that i'm starting on my rafters is it best to let the tails run long and cut to size after they are all up?
Cut them on the bench. Why would you run them long and cut later for no reason? Your walls are straight, you use a common rafter as a pattern with the overhang on it already and cut away on the bench. No need to cut later, at all.
To top it all off, you're not really used to framing. Now you're going to go up on a scaffold with a circular saw and cut a plumbcut and level cut on an overhang that you could safely cut on the bench.
For me to cut the overhangs later(which I would never do) would be no problem because I've been using a saw my whole life and I know the saw like the back of my hand. For you cutting on the bench is the best option.
i'm wit joe.....
cut 'em to fit.... worry about it if they don't fit....
ridge straight ,floor level, walls parallel, square , lined & level..... the rafters should fit...you cut the birdsmouth , right ?so, i assume if the raftertails don't align.... then the birdsmouth did't eitherMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
I'll chime in here...
I was taught to cut em after, and did so for a long time. I have, however, seen the light in the last few years, and begun cutting on the horses.
I will say though, that there are a few things that are key in doing so.
First, I'm fanatic about stringing walls. My guys know that if the string is set and the walls are braced off, I had better not see any more than a 16th inch variation anywhere. Use long braces. Laws of physics prove that a 16' 2x4 on a shallow angle do a better job holding walls straight with the forces of roof rafters, wind, etc, pushing on them than 10 footers on a steep angle do, or worse, 8 footers partway down.
I also always run a sub-fascia. I'm not crazy about cedar or pine 1x nailed into the end grain of a rafter. Replaced several, just doesn't hold as well as into solid 2x stock. Makes it easier for the gutter man, too. If you do end up with a little wiggle somewhere, you can tap the sub out to straighten. Gives solid nailing for soffit also. Solid edge to nail roof sheathing to.
Be picky about your walls, and cutting your rafters, and you'll be fine cutting on the ground. Lots quicker, too in the long run.
Bing
What if my walls are off a hair or so?
What if my walls are off a hair or so?
Then you cut a hair if there's one to long, add a hair if there's one to short. This is why I told you in one of your threads to string a line and brace your walls. It takes 2 minutes to do that and do it right.
Make a common rafter pattern including the overhang and scribe every single common rafter with that. You can't go wrong with a scribe unless you can't use your saw and screw up the cuts with the saw.
For you, make up a small pattern with a plumbcut, birdsmouth and overhang scribed from the common rafter pattern and use that small pattern to scribe your Jack rafters.
Measure and cut your longest jack rafter and then from the long point of that top of the plumbcut 45° on the jack rafter measuring down 16-7/8". Those will be the exact length of each remaining jack rafter.
Joe Carola
Always cut them on the saw horse. This reminds me of a crew framing a house next to one that I was framing. They would lay the bottom plates and then brace up the corner posts. Then a guy with a step ladder would nail the top plates on and go back and fill in the remaining studs and headers. Needless to say we framed all the walls of a large ranch with sheathing in one day while they framed maybe 3 small walls.
I saw a Polish crew do that back in 1983 on a development I was framing in. It was insane. From what I remember was they set the corners like you said and then they set a stud far enough away for a 16' top plate and another stud in the middle and then added the studs in between.
Joe Carola
Exactly!
I'll give it a shot Joe. I did string line like you said and they are pretty straight but it seems things move around a little.I already have a pattern also. I used some of the rafters from the old roof that came off in the demo.
How will you mark the HAP cut on the hip?
Joe Carola
This is how I was going to cut my hip rafters.1. Use my framing square and set it to 4/17 and mark both sides of the tongue for my plumb cut. Set my saw to 45 deg. and cut the bevel cut. Cut outside line first turn around and cut inside line.2.Figure my hip length per rafter tables. Measure from tip of rafter and mark where my plumb cut for birdsmouth will be. Set my square again to 4/17 and mark the plumb cut. Get the hap from my common rafters and mark the hip to the same hap and layout the seat cut from the hap mark I just made. Cut it.3. Take the depth of my common rafter seat cut and do layout to rip down the tail so the tail matches the commons.Can you fill me in on what i'm missing.Thanks
2.Figure my hip length per rafter tables. Measure from tip of rafter and mark where my plumb cut for birdsmouth will be. Set my square again to 4/17 and mark the plumb cut. Get the hap from my common rafters and mark the hip to the same hap and layout the seat cut from the hap mark I just made. Cut it.
That's exactly where I knew you would mark it and that's where everyone makes the mistake unless they are shown where to mark the HAP cut.
You can't mark it there because your hip is running at 45° and where the mark you are making will hit the outside corner of the building, that HAP cap you made doesn't hit the plateline where the side of the hip rafter hits the plateline where it's supposed to be at the same height the HAP cut is for the common HAP cut.
You have to come in half the thickness of the hip from that line you mark towards the top of the hip and then mark the HAP cut the same size as the common HAP cut and that will set the hip at the right height.
You will see in this drawing I made a few years ago the reason why. You will see the little rise and run that shows you the triangle that would make the hip HAP cut sit a little higher if you don't nark it where I';m showing you. With a 4/12, it's only about 3/16". But with a higher pitch like a 12/12, it's 1/2" and more noticeable.
Joe Carola
Joe is that why some bevel the top of the hip rafter?
3. Take the depth of my common rafter seat cut and do layout to rip down the tail so the tail matches the commons.
You don't have to do that unless your overhangs were cathedral. Are they? I didn't think they were. If you have level soffits, you don't do anything to the hip overhang. Your hip could be a 2x12 and you don't have to rip it. Just cut the plumbcut height and then the level cut.
Joe is that why some bevel the top of the hip rafter?
That would be the reason if one were to bevel a hip running at 45°, but you never have to do that in your case with the hip running at 45°. Marking the HAP cut where I showed you takes care of that and puts the HAP cut at the same height at the plateline as the common HAP cut. If you have a Bastard hip, that's when beveling comes into play.
Joe Carola
Edited 9/27/2008 8:04 am ET by Framer
Joe is this the same process?
Yes, it is.
They can't get your Goat if you don't tell them where it is hidden.
Perfect.
BOF,That method is more for determining the drop and as a consequence you can lay it out from there, but in all likelihood you are going to know the hip drop long before you get to a hip rafter, in your case about 3/16".Measuring down the building line, where you originally said you wanted to mark your H.A.P., the H.A.P. value - the 3/16" brings you to the same layout point in less steps. Even if you employ the other method you still have to bring the seat cut back to the building line. http://www.josephfusco.org
http://www.constructionforumsonline.com
Something to help illustrate the point.http://www.josephfusco.org
http://www.constructionforumsonline.com
Thanks Joe.
BOF,Anytime.Here's a way to do the same thing but you don't need to have your hip rafter laying around ;-).http://www.josephfusco.org/Tips/tip0002.htmlhttp://www.josephfusco.org
http://www.constructionforumsonline.com
BOF,Here's one last bit of info:http://www.josephfusco.org/Articles/Roof_Cutting/Advanced/Hip_Drop.htmlhttp://www.josephfusco.org
http://www.constructionforumsonline.com
Really good info. I bookmarked your site, i'm sure i'll be needing it.
Here's a picture of the hip length mark and the mark coming in 3/4" (half the hip width) on a 2x10 with the framing square showing how you will mark the HAP cut at the right spot just like my drawing. That HAP cut is the same as the common rafter HAP cut.Joe Carola
Just to make sure Joe.1. Get my hip length per rafter table.2. Mark the length then come in 3/4" (half thickness of rafter).3. Use the same hap as my commons. Mark it off and cut it.Another question Joe. If my current rafter tails are 2' what should my rafter tail be for my hips?Thanks
1. Get my hip length per rafter table.
2. Mark the length then come in 3/4" (half thickness of rafter).
3. Use the same hap as my commons. Mark it off and cut it.
Yes.
If my current rafter tails are 2' what should my rafter tail be for my hips?
2'10-7/8"
How are you figuring the commons and hip? Are you using the tables on the framing square?
If so,you should be figuring the Hip overhang the same way your figuring the hip length. 2' is the run, just like having a 2' common rafter run. Your framing square says 17.44" under the " Hip or Valley Rafter Length" column under your "Common Rafter Length Per Foot Run" column.
Multiply 17.44 x 2= 34.88" or 34-7/8" (2'10-7/8")
Joe Carola
Joe I was using the "Full Length Roof Framer" book for my commons and hips. I need to learn to use the framing square it's right there in front of me why not use it to figure the lengths.
Here's the picture again where you cut the birdsmouth for the hip.Joe Carola
What is the exact width and length of the building? Also what is the exact overhang? Is it 2'? Also some people here include the sheathing as part of the rafter span, I never do. Are you, or are you measuring from outside of plate to plate?
Joe Carola
That brings up another question Joe. Which way should I measure my existing overhang? Here is a pic of my current overhang.
Measure existing overhang exact from the outside of the top plate level to the back of the fascia.
If your trying to match the existing roof pitch/overhang and fascia lines, you have to make the birdsmouth the same as the existing rafter birdsmouth because I think you said that you were using 2x6 rafters and your existing rafters are 2x6 and the existing pitch is 4/12 like the addition.
So, you have to match existing overhang and forget about any other overhang calculation. If you tell me the exact overhang, I can give you the exact hip overhang length.Joe Carola
It's all covered with plastics and tarps right now so it won't be till tomorrow before I can get you the dimensions. I do have some old rafters that I can use as templates for the birdsmouths.
I do have some old rafters that I can use as templates for the birdsmouths.
There you go. As long as the old rafters are 2x6's and the new ones are 2x6's.
What is the width and length of the building?
Joe Carola
Joe 43' 7 1/2" long by 26' 5 1/2" wide.
Joe 43' 7 1/2" long by 26' 5 1/2" wide.
Lengths without overhangs.
Common Rafter = 13'10-9/16"
Hip = 19'1-9/16"
Ridge = 17'3-1/2"
Joe Carola
Thanks Joe. The ridge seems short though.
The ridge seems short though.
Why?
Joe Carola
Joe isn't the ridge the length of the building minus half the span or am I missing something? Did you figure it with a hip on both sides?
Joe isn't the ridge the length of the building minus half the span or am I missing something?
There's many ways, but remember coming in the sides the actualk run, which is 1/2 the span minus 1/2 the ridge thickness?
So your case.
26' 5-1/2" - 1-1/2" = 26' 4"/2 = 13'2" (Rafter Run)
Come in each side of the length which is the run x2 = 26'4"
43' 7-1/2" - 26' 4" = 17' 3-1/2" (Ridge Length)
Or you can just do this.
(Length) - (Width-Ridge thickness) = Ridge Length
Did you figure it with a hip on both sides?
Yes, I did. Do you not have that?
Joe Carola
Just one side of the house Joe.
BOF,To get the ridge length you take the
building length -
the building width +
the thickness of the ridge.Pretty straight forward.http://www.josephfusco.org
http://joes-stuff1960.blogspot.com/
BOF,If you want to use the square the you'll need to learn how to step off a rafter, or at least know how many steps there are and then multiply by the unit length under that rafter pitch.Or you can just get a calculator and take all the fun out of it ;-)http://www.josephfusco.org
http://www.constructionforumsonline.com
Edited 9/28/2008 1:19 pm ET by Joe
Joe i'm the kind of person that likes to be able to keep working even when that batteries die out. So I better learn to use it.
BOF,That's good to know as most guys just want to run out and by a calculator, which don't get me wrong is a great tool and a big time saver, but if you use one straight away you seem to miss becoming "intimate" with your roof framing.Let's face it anyone with a CMP or SC can push the buttons and get the answers, but it's a completely different animal when you frame with just a tape, square, line and bevel.http://www.josephfusco.org
http://www.constructionforumonline.com
What is an "SC" calculator?I use a scientific calculator and I feel that it gives you as equal, if not better, understanding of how a roof goes together vs. using a framing square.Roof framing is, at it's root, just geometry. If you can figure a roof using the square root and trig keys on a scientific calculator, I would say that you have the clearest understanding of what is really going on.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
"SC" = scientific calculator.Since both my remarks and yours are both opinions there really is no way to "debate" them.All I can say is that if I had no calculator on the most complex roof I'd have no trouble in framing it.Some roof cutters become nothing more then tool carriers without their calculators. . . .http://www.josephfusco.org
http://www.constructionforumsonline.com
Edited 9/28/2008 3:39 pm ET by Joe
What if you had no framing square?I would think that you could figure out a framing square if you can figure out a calculator.I am in agreement with your CM comment, I see a lot of guys who just know what buttons to push. That works just fine until you are presented with a situation in which you don't know which buttons to use.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
I'm sure I could manage, but I hope this doesn't became a process of elimination questionnaire ;-)http://www.josephfusco.org
http://www.constructionforumsonline.com
Out of curiosity, what tool do you reach for first with a "normal" roof? Framing square or calculator?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
I guess the best answer to your question is;I always have my framing square and sometimes my calculator ;-)http://www.josephfusco.org
http://www.constructionforumsonline.com
I do most of my layout with a 12" speed square and a CM Trig. I think that calc combines the best of the trig functions with the ease of working in ft/inches.
I'm one of those guys who'd be mostly lost w/out the calc but I could frame the roof. The square is something that I'm still fairly fuzzy on, but hopefully this winter I'll finally work out Joe's article and Billy Dillon's article from last fall.
In addition, we have 3 calculators on the job and batteries, so I'm fairly covered :-) Replaced the batteries 2 weeks ago. Usually I drive over my calculator before the batteries die :-).
Tim,I remember when Blue called them big squares "girly" squares. Funny I got like 6 of them laying around. . . ;-)Actually I think he called them "slow squares". That might have been about 6 or 7 years ago. . .http://www.josephfusco.org
http://www.constructionforumsonline.com
I don't call them that anymore because most folks that use them are too sensitive. So, I now only refer to the framing square as the "speedier" square because fundamentally, it is a far superior tool and gets more jobs done faster.
All I've ever used is the small book of tables that comes with a Swanson speed square. It is idiot-proof.
All I've ever used is the small book of tables that comes with a Swanson speed square. It is idiot-proof.
Would you be able to frame any roof without it?
Joe Carola
Yes. I was nervous relying on it at first and used to check the results by hand. Beyond Pythagoras what else do you need to calculate roof framing? Of course if the weather is dry, you can always lay it out on the subfloor.
Beyond Pythagoras what else do you need to calculate roof framing?
Using that adds an extra step because you have to figure out the rise. The framing square tables are easier.
I've never seen any reason to use Pythagorean theorem before for roof framing. Maybe some people do, but I've never used it before. Framing square and/or calculator is much faster.
Also, using the book you said teaches you absolutely nothing. If you give that to a kid and t tell him to cut rafters, that kid will never know HOW a to cut a rafter.
Joe Carola
Edited 9/28/2008 8:32 pm ET by Framer
You are right about learning how to cut rafters. Using the book is a shortcut I allow myself now because I understand the theory behind cutting roofs.
I'm lucky in that I usually build from my own drawings. I include dimensions I will need and don't look forward to figuring out in the rain on site. I always calculate the height of the ridge. Clients tend to give Designers funny looks when they ask how high the cathedral ceiling will be and you don't know.
Having started as an Architect, my drawings have changed a lot since I began framing. I never leave incomplete strings of dimensions the way I used to. It's not the designers business to decide which wall the framer will build first, and forcing them to do calculations on site is a good way to cause errors. It also makes doing lumber take-offs much easier.
"I never leave incomplete strings of dimensions the way I used to. It's not the designers business to decide which wall the framer will build first, and forcing them to do calculations on site is a good way to cause errors. It also makes doing lumber take-offs much easier."Bless you!
Beyond Pythagoras what else do you need to calculate roof framing?
Some use the Construction Master calculator. I use a trig calculator - sine cosine tangent - basic trig, just about covers all you'll need to know for roof framing.View Image “Good work costs much more than poor imitation or factory product” – Charles GreeneCaliforniaRemodelingContractor.com
F&T,I agree. I wrote an article about 8 years ago on the "Simple Methods of Roof Framing" and it discusses the "Table Method" as one of the ways to frame roofs. You can frame about 80% of the roofs you encounter with the use of tables, the only down side is that most of the tables only have a 1/2" accuracy.http://www.josephfusco.org
http://www.constructionforumsonline.com
Edited 9/28/2008 9:39 pm ET by Joe
BOF,
I've got a pretty good online calculator if you ever feel the need to check your numbers if you're not sure. It will give you the numbers for just about about everything you will need to frame either a regular hip or gable roof.
http://www.josephfusco.org
http://joes-stuff1960.blogspot.com/
Thanks again Joe.
Joe's right. I should've told you that or your hip would be wrong. Extend the level line back to the hip length mark and cut the level line and the plumb line. That will make the hip hit the corner of the plate. That's how it's always done. Cutting a V is unnecessary unless you were cutting a hip that was exposed and decorative.
Joe Carola
And to further that point, since you are taking your lengths from a table, those tables usually have tolerances to 1/2". If you were to cut a "V" you'd like to be a bit more accurate.Also 2'10-7/8" is only right if the overhang is 2'. If when you say your tails are 2' do you mean they measure 2' from the building line to the fascia cut? if so then the hip tail would be 33 1/16" or there about.http://www.josephfusco.org
http://www.constructionforumsonline.com
Here's an old pic of mine - shows the h.a.p. occurs in front of the theoretical length plumb-line (which sits over the outside corner of the building). Just backs up what your photo shows.
View ImageView Image “Good work costs much more than poor imitation or factory product” – Charles GreeneCaliforniaRemodelingContractor.com
If you use that layout you'll have to do one of two things; either extend the seatcut line back to the hip length line and cut the birdsmonth with the saw set square along the hip length line or set the saw to a 45° and cut birdsmonth along the offset line to make a "V" cut to accommodate the corner on the rafter plate.http://www.josephfusco.org
http://www.constructionforumsonline.com
Joe is this the same process?
No, but it gives you the same result. Mark it like I said and in my drawing, it's a lot faster and easier to understand than what you just posted. You don't need to any math, just mark and cut it. Coming in half the ridge thickness and marking the HAP and seatcut from there solves it all.
Joe Carola
"What if my walls are off a hair or so?"I will guarantee that your walls will be off a bit.If you don't allow for a little slop in your heel cut, you'll be fighting the installation all the way. I will also guarantee that your ridge will wander a bit.So, if you want a relatively easy rafter install, then add a little adjustment factor in your heel and leave the tails run long. You will have to make the cuts off a scaffold as Joe has mentioned but I suspect you are an expert at scaffold building because you probably watch all your amigos build them all day long in your sub. You can balance on one flimsy 2x6 can't you?
Thanks Jim. I'm afraid of heights!!!!
>What if my walls are off a hair or so?<
Joe has go tyou pretty much covered but there's plces to sweat straight lines and there's place not to. If you're going to put gutters on these fascias, the straigthest of straight lines are kind of moot (within reason).
As for me, I cut the tails on the horses too.
Thanks John.
For the most a-nal framing I'll cut on the gound but touch 'em up as needed. For slight variances difficult to shave with a saw I love a 15 amp 7" sander with the most coarse sanding disks--crazy agressive.
Beer was created so carpenters wouldn't rule the world.