breezeway collar ties

[M]

I have a question. I put an addition on my "camp".... they are connected by an 8'x10' breezeway. the camp was built with an overhangs using 2x8 roof rafters 16" on center. The addition which is larger than the camp which also has overhangs but they used roof trusses made of 2x4's 24" on center. We were able to blend the two houses together by having the breezeway do the transition of 16" on center on one side and 24" on center on the other side so that the overhangs looked the same on each side. The two houses are staggered. so that the roof of the breezeway is continuous on each side. The breezeway is the problem .... I want to have the breezeway with a cathedral ceiling and was wondering if I can get away without the collar ties? I am doing the interior with 4 1/2" vee match pine. If I need collar ties then I guess I would have to block the 24" on center and make the collar ties 16" on center or visa versa. The camp portion is cathedral 16" on center but the new section will be a conventional ceiling other than the pine. Again the question is I want to have the breezeway with a cathedral ceiling and was wondering if I can get away without the collar ties? It is

8'x10' 6-10 pitch

[M]

oop.... one more bit of data... the two houses are joined together on the gable ends in a staggered fashion

[M]

oop #2 the two houses are joined together on the gable ends in a staggered fashion ... with the breezeway as the connector

[RicodJour]

You need to have either a structural ridge supporting the upper ends of the rafters or you need to have something tying the rafters together to resist the outward thrust of the rafters. Normally that is done by collar ties or ceiling joists. In your case since you want a cathedral ceiling you could tie the rafters together with some all thread and turnbuckles or even suitably sized stainless cable. Either one would give you the open look you want.

R

[M]

there is a center ridge board at the peak on the breezeway. the two buildings hold the 4 outer roof rafters. Inside there are two sets of rafters that line up.... perhaps I should collar tie those two? Or do you think I should do more?... perhaps I should photograph the situation and see what you think?

[<moo]

wow that sounds complex and weird

but its probably very simple

you have 2 building that you want to connect with a center building in the center building you want cathedral ceilings

I am assuming that you are connecting gable ends (Flat sides not the sloped sides) of buildings

What you do is strip back the overhangs to the stud wall and then PICK A ON-CENETER and frame the new roof

you totaly lost me when you say 16 on one side and 24 on the other because the rafters wouldnt line up on the ridge beam

so maybe get an architect to build you a plan or get your truss company to give you a plan free if you buy the trusses from them.

Just call a truss company and say I need 15 trusses for a new roof if i give you the floor plan measurements or can you send a guy out to take measurements

and they will either say give us your measurments or we can recomend someone to come out and measure what you need.

[M]

Well thanks for the input but it is way too late for that. The post does sound confusing. I will take pictures this after noon and post a link to them here for you to see. Basically the breezeway and the two buildings are up with the outside shell on. They are already shingled on the roofs. The question concerns collar ties on the inside in the breezeway. One side is

24 on center and the other 16". I thought about just adding roof rafters in between the 24 on center side and then collar ties to make 16" on center... but being only a short span 8x10 breezeway I wonder if I need the collar ties at all. Rico mentioned using turnbuckles. I might go with that if I really need to.

Here is a link to the outside of the building

here it WAS during the construction... keep in mind the building is completed on the outside like the other photo.

[<moo]

well first its a very nice house in a nice area I hope you can use those rocks for decoration

but I am still lost a bit

i hope that helps

[M]

I will probably just collar tie two of the rafters that meet at 48" and the other two that meet at 96"..... it is only an 8 foot span.... I am not changing the rafters as they are purposely 24" O.C. on one side and 16&#39; O.C. on the other for cosmetic reasons. The rafters do have bird mouth notches to hold them to the walls ... If I have to I will turnbuckle them together... or block one side to get rafters to meet in the middle and just have narrow channels for insulation.... or maybe crooked collar ties... lol... or none at all.

[<moo]

you know thats fine you dont have to tie in each rafter set and I would guess you can probably get away with not matching the rafters at the ridge beam

but you will need nailing areas to attach drywall so just block between the rafters on one side or the other and install nailing (umm fake ties) so you can attach some drywall

but I got to say you probably shouldnt have tried to match your rafters for decorative reasons.

bob could probably give you a better understanding of roof loads

what ever you do dont put in angled ties thats just useless

[RicodJour]

For the life of me, I can&#39;t come up with a reason for doing it that way other than you had a certain amount/size of lumber available and worked with what you had. Please tell me what I&#39;m overlooking.

R

[marson]

Must be exposed rafter tails.

[RicodJour]

?? Why would exposed tails look better with one spacing on one side and another spacing on the other side? The exterior picture the OP posted has very little overhang and doesn&#39;t seem to show exposed tails

- can&#39;t really tell, though. I think I&#39;ll wait for the OP&#39;s explanation.

R

[marson]

well one side is matching the tails on the old cabin and the other side is matching the tails on the addition?

[M]

yes the rafter tails are different. The older side was 16 on center exposed rafters and tails.. (see photo) and the new section which is lighter in color is 24 on center. The tails are exposed under the over hang by about

12 or 14 inches. How about if I sister the rafters to take up the areas and then use collar ties. I have pics in

Like I said it is only an 8 x 10 breezeway... but it is Maine so I guess snow load is a concern. Marson had a suggestion but I don&#39;t understand what he is saying exactly about the posts and the headers. He replied in my other post.

[M]

yes exactly

[marson]

hopefully this helps....so the weight of snow on the roof will want to push the ridge down. since the rafters push against each other, the rafters want to push the walls apart. this is a bad thing. collar ties prevent this. but the other way to prevent this spreading apart of your walls is by holding the ridge board up with posts on either end. this is known as a structural ridge. (the posts need to transfer the load to the foundation--thus you would need headers over the doors into the breezeway to accomplish this.) you have a 2x8(?) ridge which is probably insufficient (?) to span 10 feet, so you would probably need more of a beam--which could be put under your current ridge board.

[HerHusband]

Assuming a 40 psf roof load, the 8x10 roof would hold 3200 pounds, or 1600 on the ridge beam. According to the tables I have, a 2x8 beam will only support about 1400 pounds over 10 feet (1400 fiber stress). A 2x10 ridge would probably be adequate though, since it supports 2237 pounds.

Anthony

[M]

And how much snow would it take to get up to 1400 lbs over an 8 x 10 breezeway roof?... 20- 30 feet of snow? I will do something though because I like over kill.... I am thinking of supporting under each end of the ridge board and collar tieing the two sets of rafters that match up ... and maybe a turnbuckle or two

[marson]

FYI, if you had 100" of snow in a season, and the snow had a 1 to 10 water to snow ratio, that would add up to about 54 psf. You also might need to add in drift loading. So it isn&#39;t extreme overkill by any stretch