# Alternative to collar ties



## epson (Jul 28, 2010)

A nice alternative to collar ties is to use a scissors truss. Really the best advice would be to contact a local engineer who can personally inspect the structure and give you the proper advice on what you can do.


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## Willie T (Jan 29, 2009)

Collar ties may not needed if metal connectors were used to fasten the rafters to the ridge. And even if they are needed, they can often be moved upward quite a bit because they are legal anywhere in the top third of the attic space, and you might want to make a little bit of a flat ceiling up there anyway if you are finishing it off some.

But without understanding better what this "bump out" is and how it's constructed, I wouldn't recommend messing with it.


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## Proby (Jul 17, 2010)

With the design of the roof, I can't move some of them up any higher.

In my instance the rafters are actually running into a hip rafter, not a ridge board. Since this is triangle shaped, the rafter on the outside don't run up as high as the ones in the middle, so the collar ties are down low.

Are there any types of clips that I could use to connect the rafters to the hip rafter instead of spanning the attic to the rafters on the other side?


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## Willie T (Jan 29, 2009)

Sorry, I'm mostly a visual person. I'm kind of lost as to trying to see this in my mind's eye.


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## Proby (Jul 17, 2010)

Here is a drawing looking at the house from directly overhead:










The blue lines are normal rafters. The red lines are the rafters that I am having a problem with, mainly the shorter ones on the sides. Since these are short, the collar ties are real low. All the rest of the collar ties are nice and high which gives me plenty of room up in the attic, but the shorter ones are ruining it. If there is a way to attach those rafters to the hip board without using collar ties it would be great.

The peak of the roof is about 10' off the floor. The collars ties are current at about 5' off the floor. I can move most of them up to 7' without a problem, except for the ties connecting those shorter rafter to the rafters on the other side, I can't raise those.


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## Willie T (Jan 29, 2009)

This is what I think you are saying.....

But I don't know if your larger rafters run all the way down as shown by the lighter end. I would assume that they do.

But I drew it with them cut off (darker end) and attached to the valley piece also just in case someone got a little wild in their framing..

From these drawings, can you explain where the offending collar ties are?


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## Proby (Jul 17, 2010)

That's pretty close to the way it is. The differences are that the peak on mine is much higher and that there are no "inner rafters" underneath the bump-out. The rafters that makeup the triangle bump-out are the only rafters on that side. The side which I circled in the image below is the way it is.

I circled the area where the rafters are so short that they require collar ties to be too low to use the attic. I assume the really short ones don't matter that much. The really tall ones towards the center are ok because I could put a collar tie across to the rafters on the other side. My issue is with the intermediate sized rafters.


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## Gary in WA (Mar 11, 2009)

1. Do you have ceiling joists below to walk on that are bearing on the outside walls? What size and how far do they span?

2. Collar ties are in the upper 1/3 to hold the rafter peaks and the ridge board together in a high wind. Required by the Southern Building Code only, as far as I've read. 
It sounds like they are nailed to the middle of the hip jacks and the valley rafter? 



3. Have you called the local B.D. and asked them if collar ties are required?


Nice drawing Willie. FYI- valley/hip jacks always run up and down, never side to side.... but I see what you meant.


Be safe, Gary


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## Proby (Jul 17, 2010)

GBR in WA said:


> 1. Do you have ceiling joists below to walk on that are bearing on the outside walls? What size and how far do they span?


 Yes, the joists run parallel to the rafters. They are 2X8's. The joists span from the outside wall in to the center of the house where they lay on the main load bearing wall. I would only use the middle of the attic, about 5' out on each side of this load bearing wall.


> 2. Collar ties are in the upper 1/3 to hold the rafter peaks and the ridge board together in a high wind. Required by the Southern Building Code only, as far as I've read.
> It sounds like they are nailed to the middle of the hip jacks and the valley rafter?


They are nailed as high as they can be on the hip jacks. There are no collar ties on the valley rafters.




> 3. Have you called the local B.D. and asked them if collar ties are required?


 No. The thought that they might not be required didn't even enter my head.


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## Gary in WA (Mar 11, 2009)

You will need to furr the rafters down to get the require insulation in, R-49: http://www.ornl.gov/cgi-bin/cgiwrap?user=roofs&script=ZipTable/ins_fact.pl

2x8- 16”o.c. will span 12’8” and 24”o.c. = 10’6” depending on species, for a 40# floor load. 
You may need some rigid foam board and new vents for attic above/below the slope ceilings.

Be safe, Gary


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## Proby (Jul 17, 2010)

Oh no, I am not putting walls/ceiling up there, I just want to move the collar ties up so I have headroom. I'm still going to leave it unfinished.


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## Willie T (Jan 29, 2009)

Don't know what you can get by with where you live, but down here in Hurricane Land we are building them much like this anymore because we are required to strap down (Simpson plates) all the "Bump out" stuff to rafters or trusses directly below them.

I really don't know what to say about your collar ties except that they almost sound like rafter ties. (Very necessary), and often collar ties would be required extending directly from where the flat pieces of the "Bumpout connect to the main rafters... on across to the other side of the house, tying in to the opposite rafters.


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## Proby (Jul 17, 2010)

In this last image the bump-out is just an overhang. In my house that bump-out is the house itself. There are no inner rafters on my house inside the bumpout, the rafters coming down from the ridge stop at the valley where the bump-out begins.

My ceiling joists act as rafter ties. What I currently have are collar ties, the only reason they are low is because some of them (the ones in which I circled in red on the image I posted above) *can't* be any higher. I guess they wanted them to be a uniform height across the whole way so they put them all at that height.


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## Willie T (Jan 29, 2009)

I would have built that "bump out" with the rafters turned 90 degrees, and made a gable out of it. But having done it hip style the way they did, I imagine it honestly SHOULD have been additionally framed with full length tie backs something like this.

Rafters butted in the center like they are now should not be relying on that valley rafter to support all the varying loads the center span of a set of rafters is subjected to.


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## Proby (Jul 17, 2010)

I'll probably get over there to do some work on the weekend, I'll take some pics to show you what it looks like.


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## Willie T (Jan 29, 2009)

BTW, if you have SketchUp, and want these SKP files to play around with, PM me with an email address, and I'll send them along to you.


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## Willie T (Jan 29, 2009)

GBR in WA said:


> 1. Do you have ceiling joists below to walk on that are bearing on the outside walls? What size and how far do they span?
> 
> 2. Collar ties are in the upper 1/3 to hold the rafter peaks and the ridge board together in a high wind. Required by the Southern Building Code only, as far as I've read.
> It sounds like they are nailed to the middle of the hip jacks and the valley rafter?
> ...


I'm certainly with you there. But the way the OP described it with collar ties joining the valley and hip jacks, I couldn't envision any other way they might have done it. I'm kind of lost as to how they would have installed collar ties on jacks perpendicular to one another.

Trust me, the way I drew it would hardly be a choice I would make for my own work. :no: 

(The picture below is kind of what Gary is talking about....... and the standard way most everyone frames...... I couldn't find anything exactly like Proby described and showed in his drawing.)


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## Proby (Jul 17, 2010)

That valley in there is the way mine is framed.

I didn't put the valley jacks into my drawing because I got lazy towards the end and they really don't effect the collar tie question.


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## Proby (Jul 17, 2010)

You see where I put the red line? Those rafters have collar ties spanning across to the other side of the roof. The problem is that those collar ties are too low. I would like to remove them and find an alternative.


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## Willie T (Jan 29, 2009)

OK, I think I finally see what you mean. The collar ties attaching the rafters toward the center part of the "Bump Out" are higher because the peak of the "B O" is, naturally, higher.

So, in order for them to run collar ties, front to back, where the valley begins to descend the slope of the main roof, each collar tie had to be installed lower than the previous one above it. And they keep getting lower and lower till the bottom ones are probably only a couple of feet above the ceiling rafters. Right? (Much like I drew in Post #15, right?)

If I finally have it right, there may be hope for you. But it may require engineering approval and an OK by the Building Department.

Collar ties are usually only required on every other rafter. So, you can probably surmise that the uplift they are expected to contain is not all that great. (Otherwise they would be required on EVERY rafter.)

So, it may be possible to install a long, perpendicular piece across the midsection of all the "Bump Out" rafters, spanning all the "B O" rafters, tying them all together at about the center of the longest ones. (This might have to be steel)

From there, it just might be possible to get away with only two fairly high collar ties, one connected to each of the second longest rafters. (The ones to either side of the center rafter of the "B O".)

This is, admittedly a long shot. But an engineer just might see it as workable. Of course all this hinges upon being able to solidly tie all the "B O" rafters together somewhere around their midpoints.

But, no, I don't think you could get away with just removing all the low collar ties...... not without somehow reestablishing some uplift prevention to replace them. And I think it would probably take more than clips to either the valley or hip rafters.

BUT............. If you blow up the picture above and look carefully, you will see collar ties installed all across the main roof. However the hip where you drew your line doesn't appear to have any at all. Up North, you guys often don't need to jump through the wind pressure hoops tropical areas have to. So...................... who knows just what the building dept may say?


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## Proby (Jul 17, 2010)

Willie T said:


> OK, I think I finally see what you mean. The collar ties attaching the rafters toward the center part of the "Bump Out" are higher because the peak of the "B O" is, naturally, higher.
> 
> So, in order for them to run collar ties, front to back, where the valley begins to descend the slope of the main roof, each collar tie had to be installed lower than the previous one above it. And they keep getting lower and lower till the bottom ones are probably only a couple of feet above the ceiling rafters. Right?


 Yes, exactly. But what they did was they put ALL of the collar ties at a single height, about 5' off of the floor, instead of making some higher and some lower.


> (Much like I drew in Post #15, right?)


 Similar, but my collar ties are going to the B.O. rafters themselves. In your image the ties are running into the hip board.


> If I finally have it right, there may be hope for you. But it may require engineering approval and an OK by the Building Department.
> 
> Collar ties are usually only required on every other rafter. So, you can probably surmise that the uplift they are expected to contain is not all that great. (Otherwise they would be required on EVERY rafter.)
> 
> ...


Makes sense. 

I did notice how all the rafters on the B.O. of the roof you pictured didn't have collar ties so I was thinking the same thing.

I'm surprised that metal clips (like hurricane clips) aren't enough to secure each rafter to the board.


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## Gary in WA (Mar 11, 2009)

You don't need ties on hip *jack* or *common *rafters. The only application is *opposite common rafters on a gable roof*, built under the Southern UBC. Ask locally, if still in doubt. 

Be safe, Gary


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## Willie T (Jan 29, 2009)

There ya go. Yank 'em.


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