ceiling joists and ties to rafters

[rwanders]

I am planning a 24X24 cabin with partial loft----10ft deep and then there is a 14 ft open area then a 10 ft deep deck & balcony with the 12/12 roof extended out over both. I plan to use 24 ft engineered wood I-beams for floor/ceiling joists with 2X10 rafters. I will be mating the rafters to joists in the loft area and again in the 10 ft deep balcony which will be accessed by 14 ft bridge from the loft to a door in the gable end wall.  I will be framing in collar ties at about 4-5ft below the peak throughout the building. Will I have an unstable roof system if I don't have joists all the way across? I am willing to double up the collar ties and bolt them through the rafters at the side wall if that would help. I am obviously a little worried about the outward pressure of the untied rafters in the 14 ft open area I have planned.

[glenn kangiser]

Welcome to the forum.  That would be more of a question for a local engineer looking at your plans.

Is there a possibility of putting beams on 4 foot centers that would hold your bridge?

[rwanders]

I've thought of doing that if I do need the ties. It presents another problem though-----to match the plane of the loft floor and the balcony entrance would place the beam right in the path of the bridge. I would have to come up with a beam small enough to allow me to provide support for the bridge yet large enough to span the 24 feet from side to side. alternatively, if I can hang 2X10s between the rafter ties and not overstress those beams that just might allow . me to meet both needs. I agree that an engineer will need to be consulted whatever I decide. 

[glenn kangiser]

You might be able to get special attic trusses designed that would do the trick.  Check with a truss company and tell them you want the trusses on 4 foot centers and see what they can design.  Attic trusses have open space in the middle for a room and may look cool if designed special for you.

[PEG688]

You might be able to get special attic trusses designed that would do the trick.  Check with a truss company and tell them you want the trusses on 4 foot centers and see what they can design. 


Attic trusses have open space in the middle for a room and may look cool if designed special for you.

  Then you'd have to use a 2x 6/8 roof sheathing , no OSB or Plywoods gonna span 4' . Starts a whole other issue, costs etc. Do able ? Maybe , Like they say if you have enought money you can do just about anything.


Most trusses will need to be covered with D/W or something , so the space may be cool , or you may like the "look" of gang nailer plates  Glenn is a bit < ah < Odd

[glenn kangiser]

Yeah - I was saying truss company but was thinking of a self built nice looking truss as far as looks -- not a code one -- but I didn't think of the 4 foot plywood problem.

[rwanders]

Must be ESP, but I believe your input made me think a lot more about my problem----pretty sure I have figured out how to provide some rafter/wall ties and allow for my bridge to the balcony. It means that I will have to use a fabricated beam of 24 ft 2X6s to allow enough space for 2X10 @16"oc for the bridge. This will allow for at least 6'7' headroom for the two beams required for the 14 open area. I will not be able to tie them directly to the rafters at the top plate but intend to let them into the 2X6 stud wall about 9" below the top plate. I will double the 2X6s ( one each side of a wall stud) and use carriage bolts to sandwich them to the studs. I will also put some solid 2X6 blocking between the wall studs across the open area to help the bolted stud/beam combination to "share the load". Intend to consult with a structural engineer friend to confirm viability of this scheme. Thanks for your input!!  I have been poring though this website---it's is a wonderful resource for anyone contemplating/fearing "taking on more than he/she should be chewing". I may lose some of that precious "open space" but I will certainly sleep better under that roof.

[glenn kangiser]

That seems to be the way it goes here.  People come here with questions and somehow usually end up with ideas or solutions.

Glad you enjoy our/your site and find it useful.  Letting us know that makes it worthwhile for us to keep doing it.