First Day builders--A framing question:

[Erin]

For that matter, non First Day-ers can respond, also!


OK, so we've been planning to build a post and beam structure with curtain wall type panels (like ISPs, only not structural, as there's no need).
But rather than doing actual timber frame construction with heavy beams (or even hybrid P&B with Simpson type connectors), we're looking at doing built up posts and beams using standard structural lumber.  Much like First Days.

From what I can tell in pics (I have the CD, btw) it looks like the framing posts are 3, 2x6s sandwiched together.  Is that right?
From an engineering stand point, this seems like overkill as they're on 3'4" centers.  We were thinking 3, 2x4s sandwiched would still be strong enough, but cheaper. 

Is there some reason 2x6s would be better? 
Some fit-thing that I'm not thinking of?  ("Fit" as in the spacing between posts to make door/window framing easier.)

Thanks in advance for any thoughts!

[John_C]

Whether or not it's overkill would depend on may factors, among them

Are you supporting a roof load only, or a second floor as well?

What is the roof load? Span? Anticipated snow load? Any severe loading.. hurricane, earthquake?

In most places any type of post & beam construction will require an engineers stamp. Maybe some others will jump in here but I don't know of any proscriptive answers.

[Erin]

No engineer's stamp required.  The only thing our county cares about is septic.


We're building in NW KS, so no hurricanes, or earthquakes, but tornadoes are always possible (and of course make hurricane ties recommended)
yes a second floor, but as a loft, not a full story.  Ground snow load is 20-25 (we're right on a line).  The roof is going to have a 9/12 pitch.
When we had first started looking at Alex Wade's designs (which, upon further research, I discovered a First Day basically is), he said that 4x4s set 8' oc is sufficient in most cases, but 6x6 looks more substantial and makes it easier to size beams.
But, where we're setting them only 3'4" OC, and are tripling to be 3.5"x4.5" it seems like this should be more than adequate, doesn't it? 

[MountainDon]

The first thing that sprang to my mind was how thick dp you need for the insulation you want to use? Or maybe that's not an concern if you plan to use something like sheet foam over it all.   

[Erin]

Yep, we're basically going to do sheet foam over it all. 
http://www.firstdaycottage.com/Main.html

The frame is internal, with the sheathing, insulation and external sheathing/trim applied to the outside of the frame.

[MountainDon]

Ah! Then it's a matter of strength.

And calculations, if you deviate from plans.

[Daddymem]

Ours is constructed with 3 2x4's sandwiched.  I think there is a garage design that uses the 2x6's.

[Erin]

oh good!
That's what I was hoping to hear. 

(I'd had this all drawn out and DH was looking through the CD and said, 'Wait a sec, hon...")
I worried for nothing.  lol

[Daddymem]

If you go with a FirstDay-just a word of advice.  Don't fret too much over the floorplan.  Go see David (if you can), tell what you want and need and he will whip up a floorplan WITH you.  He is a master at it and most people walk out with a totally different plan than what they walked in thinking they wanted.  You may even walk out with a different style house than you are thinking of now.  They have put so many people in their houses they know what will work for you.

We have our third rugrat coming along in March so we'll be adding on to ours as soon as we can scrounge up money or sell the other house.  We did the New Cape with 2' kneewalls.  I think a garage as an addition will be what we go with but who knows until you see David.

Good Luck!

[Sassy]

Congrats on the coming additions!