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
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.
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?
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
and they will either say
give us your measurments or
we can recomend someone to come out and measure what you need.
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.
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' 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.
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
bob could probably give you a better understanding of roof loads
what ever you do dont put in angled ties
thats just useless
For the life of me, I can'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'm overlooking.
?? 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't seem to show exposed tails
- can't really tell, though. I think I'll wait for the OP's
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't understand what
he is saying exactly about the posts and the headers. He replied in my
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.
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.
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
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't extreme overkill by
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