# Stumped by rafters



## tough198 (May 1, 2008)

Hi. I am building a P&B garage 24x28. I am sticking in the roof open span. I have my posts and headers up and top plates in and began to put in the rafters which were all cut from the same pattern. I have the front side in and had started on the back side when I realized that the birds mouths were pulling off of the top plate. By the time I had gotten about 6 rafters in the birdsmouth was off the plate by 2". I have checked the posts for plumb the building for square and the outer walls for width and all are witin spec. I am really stumped here because there are no gaps in the front side of the rafters which would indicate that the ridge beam shifted and it is very obvious that the ridge beam is still straight. Any advice on what to check next. I am really stumped here as evidenced by my asking total strangers for help and with no visual aide. DOH!! :wallbash::confused1:


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## OCRS (Apr 29, 2008)

Is it possible that the initial length measurement for the rafters was little long?


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## tough198 (May 1, 2008)

OCRS said:


> Is it possible that the initial length measurement for the rafters was little long?


I actually took the first one (the gable end and the pattern) ) back down and measured it and it was to spec. and it fit perfectly as did the one opposite it.


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## OCRS (Apr 29, 2008)

Have you tried doing both sides of the ridge at the ends then infilling?


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## tough198 (May 1, 2008)

OCRS said:


> Have you tried doing both sides of the ridge at the ends then infilling?


That is how I did it. I put up both gable ends then started at one of them and worked my way down. Two on one side, then two on the other. Both gable ends fit perfectly on both sides


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## OCRS (Apr 29, 2008)

Somethin's bowed somewhere


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## BuriedHammer (Apr 10, 2008)

How did the bird's mouths run out? You should be keeping them tight as you set the rafters.

IF everything is in spec as you say, and the rafters are all the same, then your ridge is not parallel to the top plate. Check to confirm the top plate is straight and level, then set the rafters keeping the bird's mouths tight and the top points on the rafters aligned with the top of the ridge.

In other words, if the top plates are straight, level, and parallel, and the rafters are identical, then setting the rafters with the bird's mouths tight guarantees (pretty much) that your ridge is level, straight, parallel to everything, etc etc.

Anyway, just my 2c, hope it helps


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## tough198 (May 1, 2008)

OCRS said:


> Somethin's bowed somewhere


Thats the part that has me stumped. You would think that it would have to be but every piece has been checked, double checked and triple checked and nothing. Its like the laws of physics have been repealed


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## BuriedHammer (Apr 10, 2008)

tough198 said:


> I have the front side in and had started on the back side when I realized that the birds mouths were pulling off of the top plate.


I missed this on first read. You set all the rafters on one side of the ridge, then went back to set the other side? If so, the weight of all the rafters on that one side is pushing your ridge board back and throwing off the opposing rafters. You may be able to raise/brace that ridge board somehow, but you also may have to remove the rafters and start over setting both sides of the ridge as you go (that's how it's done, to prevent this problem).

Unless I'm misunderstanding you.....


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## OCRS (Apr 29, 2008)

I'm not sure how much of this you've already done but I'd say plumb the ridge ends and check for center, string the top of ridge and check for straight, string top of plates and check for same. If all that checks out, i think maybe your template shifted while marking some of your rafters.


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## Kent Whitten (Mar 24, 2006)

There's something wrong somewhere (obviously)

It sounds like your ridge is straight. Is your ridge bowing down in the middle?

Walls bowed inward? Doesn't sound like it would be. Top plate on wall crowning up but doesn't sound likely.

What you should have done on the rafters is set outsides first, then set one pair in the middle. This keeps things RELATIVELY straight, not perfect, but the job will go much better splitting things in two, then doing it again if you have a long run of rafters.

Front, Back, Middle, then blow and go. Everything HAS to be straight and parallel and flat (not necessarily level, but it does help you more) or it doesn't work.


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## cmansmith (Apr 15, 2008)

*Wow*

Start by nailing the birds mouth first put it where it goes and nail it good. Then have a buddy, preferably a fat one push down on the rafter while you beat the ridge up with your hammer. Start in the middle, If that doesn't work, put a stiff back under it and wedge it up and repeat what I just told you till you get it where it goes. Just for future reference never fill one side all in without putting rafters on the opposite side to push back. or this will happen. Oh and always nail the wall -birds mouth first. beat it into submission.


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## neolitic (Apr 20, 2006)

OP, Does your pattern fit in the 
center of the ridge?
If it does, maybe it's the way
you marked the rest off of the
pattern?
Put a block on top of the pattern
only directly above the 
top plumb cut and directly above
the seat cut.
Only match at these two points.
That should take care of differences
in width and crowns.


If you already did this...
good luck. :thumbsup:


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## billy d (Mar 12, 2008)

Hi Tough198 sorry to hear about your problems with the roof .Lets look at this rational.Ok if you have got a ridge plate and not what I would call a ridge beam then the spars on one side are pushing the ridge over.But you say the ridge is level and straight.So lets forget all this.Get a adjustable prop and put it in the middle of the ridge and take some weight on this.Go to the wall plate where the birds mouth does not pass and drive the claw of a claw hammer into the spar a bout 4" from the wall plate with the shaft pointing to the ridge.Get a 4by 2 set it in between the wall plate and the hammer and use this as lever and pull down till the birds mouth closes,then nail the spar to the wall plate.This will take 2men 1 above and 1below.Check the adjustable strut and may be send up now and again just to make life a little easy.I can promise you that if you walls run parallel and the birds mouth sits tight every thing else will be straight its not physics it the will to make things pass hope this helps have fun.


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## billy d (Mar 12, 2008)

Cmansmith just seen you reply lol MAKE IT HAPPEN


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## tough198 (May 1, 2008)

OCRS said:


> I'm not sure how much of this you've already done but I'd say plumb the ridge ends and check for center, string the top of ridge and check for straight, string top of plates and check for same. If all that checks out, i think maybe your template shifted while marking some of your rafters.


Is there a hall of shame around here? If so I need to walk it. The ridge board was crowned upside down. I went out for some supplies and let my crew have at it. My laborers have been on for a while and one of them recommended a "carpenter" so I took him at his word that he was the best thing since sliced bread. Shame on me. I didn't check the work when I came back or at anytime when I was checking everything that I had done. When I talked to a commercial buddy of mine, and after reading OCRS and framermans post and giving it some more thought, I strung the top of the ridge board and guess what, the crown was upside down and by the exact amount in the center that the rafters were pulling off. We got it all turned back and around and proceeded on but I was really embarrased when I discoverd what was going on. Never trust the work of someone you don't know. Cardinal rule. Thanks for all the helpful posts guys. Nail on.


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## neolitic (Apr 20, 2006)

You found it.:thumbsup:
You fixed it.:clap:
No shame! :thumbup:


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## mikec (Jan 2, 2007)

Hhhhmmm that must be one heck of a crown.


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## Charlie Roseman (May 5, 2008)

I am a low life spammer - My Post content has been removed.


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## reveivl (May 29, 2005)

Charlie Roseman said:


> I am a low life spammer - My Post content has been removed.


C'mon, what did it say? Man, these virgin mods are sure quick on the trigger... :whistling :jester:


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## OCRS (Apr 29, 2008)

He made a comment about the ridge then went straight into promoting a site


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## supercrew (May 15, 2006)

im with mickc here, a 2" crown in a 24/28' board???

first of all, what kind of material are you using for your ridges?

second, that "carpenter" needs to be demoted to lumber mover so he can pratice marking arrows for crowns.


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## RED HORSE 554 (Jun 26, 2008)

if you havent found it one thig to check is the length of each rafter cut if you marked off of the pattern rafter and used it till done they all should be the same if you transfered patterns then the length can grow with every change and if you have many changes in your pattern rafter you may have growen the rafter length.Just checking did you change the pattern once you started cutting and did you check each rafter length each rafter


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## erichhaag (Jul 21, 2008)

*square*

that building has got to be out of square. take a diagonal measurement inside on the top of the walls. (from inside the wall top plates corner to corner both ways) you may have checked the bottom for square but the top is where it counts. you would be suprised how much a 6' level will lie to you. If thats not the case I dont know what is? When you cut your rafters did you mark the others using the exact same one for all markings? label the first one that fits right PAT for pattern and mark them all with this one. Every saw cut changes the overall dimension if you keep marking with a new one everytime. If it is out of square I would use some lumber and jacks to push or pull it back into square brace the heck out of it and start anew with the rafters. Good luck. Erich


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## Stiletto3 (Jul 21, 2008)

Here's an answer.........
1. You are retarded
2. Let someone else do it for you that is not retarded.
3. Drink beer and watch them do it right and be amazed.


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