First off, big, big thanks to everyone on this excellent forum, particularly the regular contributors--Wes, Dana, Rob, Chris, Concrete Producer, too many to name here. I've been lurking here for a couple of years, and your expertise and generosity has transformed the way I see my building project, and building in general. So, I'm considering an ICF house in central KY that would have timber frame trusses in the great room. Room is 18'x24', roof is SIPs, 9:12 pitch, walls either 6" or 8" core. End walls (18' wide) would be steel-frame window wall on one end, ICF on the other. Two timber frame king post trusses (Douglas Fir) would span the 18' width at 8' spacing from end walls, bottom chord of truss 10' from floor. Floor is Hambro, above finished (or finishable) basement. My question is, could I form pockets at the top of the side walls and carry the trusses directly on the ICF wall, or would I need to use timber posts inside the room to carry the load down to the footer? For both cost and simplicity during construction, I'd rather use the wall if I can. Secondary question, could these trusses (continuous bottom chord) be stout enough to tie my walls together (resist lateral force, seismic B), or would I need some additional reinforcement there? I will definitely hire an engineer before the first spadeful of earth is turned, but I'd like to get some preliminary plans done that hopefully would not have to be totally reworked once they're reality-checked! Thanks again for all the great insights and input on this forum. Will

1. there are 2 ways to do this: a) have the trusses be cast in place or b) form blockouts prior to pour and remove afterwards - this gives you a place to set your truses into. Either way - no need for separate columns. 6" concrete core is adequte for 4 stories or more in most cases.
2. with 3 walls being ICF you should be ok. your engineer will give you a definite answer.

Curious about why ain't all walls ICF?

Earl,
Good to hear from another Kentucky voice. Where in central KY are located?
Quick and dirty look at your plan suggests you should have no problems.
Form your beam pockets in the walls before pouring the concrete. This is easily done with foam plugs.
These pockets will go through the inner foam layer and the concrete, leaving the outer foam inplace. Make sure the depth is correct to allow your SIPS to contact the outside edge of the outer foam.
Your bottom chords will serve as wall ties, provided you supply some type of bracket to lock the truss into the wall pockets. (The trusses will set in the pockets, and provide vertical loading without brackets, but to keep the walls from spreading you will need the brackets).
Of more concern would be the end window wall. I would recommend turning the ICF walls in at least 4 ft. to stabilize the corners. Otherwise, you will want to provide some type of stronger lateral cross tie than would normally be provided by a window wall.
One more question, are you buying your trusses from a mfgr, or a you building them on site? I worry about proper loading if they have not been sized out by an experienced timber truss engineer.

Thanks for the responses guys. Green--the fourth wall will be largely glass. It will face south for some solar gain onto the concrete floor in winter, but outside will be a "prow" shaped deck with roof to eliminate direct gain in summer and part of shoulder seasons.
Wes-- thanks, I was wondering whether I should turn those corners with ICF. I was thinking about perhaps some type of steel moment frame with a cross beam at 10'. I'm in Nelson County (bout an hour south of Louisville). And I will definitely hire-out the trusses. (You know anyone nearby with a good line on DF?) I've actually done a bit of timber framing myself, but don't have the tools or engineering chops for something that scale. I plan to take on the timber framing of the front porch, a side screen porch with deck above, and perhaps a cantilevered timber balcony on the second floor myself. But even for these I'll at least run some drawings past an engineer before trusting my family's lives to them!

Earl,
Check out Harmony Timberworks (www.harmonytimberworks.com)
They are located in Boone NC.
Should be able to help you with timbers and/or complete trusses.

Earl,

I am also familiar with Harmony Timberworks, very nice product. Also try sloansmill (dot) com. I do not have any business affiliation with them other than knowledge and Larry Deal (national sales manager) is a friend. They do very nice Timber Frames in any design you want. I have seen 2 of their timber framed homes - really nice frame. You can get Larry's phone number on the website. I would bet that they would make the frame trusses for you and ship them to your site. Very decent pricing.

When I build my home I will use their timber trusses.

Good luck building!
richm