Larsen truss and sheeting

[jjk066]

Hey everyone, been reading a while, decided to join to ask some questions.  At the moment I'm, a 'conventional' carpenter, but I have been working with a timber framer I know from time to time to learn.  I would like to timber frame my personal home, with a possibility of working myself into it professionally (who knows, eh)

Anyway, I wanted to ask about Larsen trusses.  At the moment, I'm liking them better than panels because of price and the fact that I can do it myself, which is an important factor to me.  I was wondering if it was necessary to sheet the outside when timberframing since they aren't structural.  It seems to me that the main reason is to aid in tightening up the home.  But I would think that a careful, creative builder could do a good job with the vapor barrier and/or dense pack and/or house wrap.  I would run some 1x's for bracing to stiffen the wall up if needed.  Am I overlooking something?

[Brad_bb]

I had to look up what a Larsen Truss was:
http://www.greenbuildingadvisor.com/blogs/dept/musings/all-about-larsen-trusses

Are you asking about sheathing the outside of the TF or the Larsen Trusses?  It would seem that you'd need to do both. 

One thing I'm wondering is, how do you sheath the outside of the Timberframe directly?  I mean if you have bents that are 12, 14, or 16 feet apart, what sheathing is going span that?  Even if you did, there would be too much flex in it.

I also wonder, how you apply an outside finish, like siding, or brick, given that the trusses are not structural?  What are you connecting to?  Is it strong enough?  I worry about high winds etc. 

An alternative to sip panels is wrap and strap.  Rooster had a good post about this a year or two ago.  Here it is:
https://forestryforum.com/board/index.php/topic,54157.msg805230.html#msg805230

I know there's another good one about using it on a house, but haven't found it yet.

[jjk066]

on the inside would be sheetrock screwed into the trusses.  The trusses would help it span between the members.  I am a little worried about the flexing, maybe one could put some diagonals in the truss like with a floor truss to help with that...?

I guess I was wondering more about the outside.  If you had wooden clapboard siding, and maybe a few 1x 'rat runs' through the trusses to stiffen them up, would you need osb/plywood sheeting?  My thinking is that you wouldn't, but I'm not a building scientist and I still have a lot to learn.  I've never done it and haven't seen it done, just wondering.

[beenthere]

jj
Welcome to the Forestry Forum.

[Brad_bb]

Granted having no experience with Larsen Trusses, I would be concerned about flexing, especially with drywall joints-cracking.  I would also be concerned about having enough material to screw into from the inside and the outside for the clapboards especially. 

Why do you want to go so thick on the walls?  Are you planning to use cellulose?  Did you read that article I posted?  The part about designing for 345 days of the year versus the coldest?

Welcome to the forums!