[Greenbuilding] Advanced Framing/OVE in Midwest?

[Chris Green]

Jason Stone and Ronald Cascio wrote:
> ----- Original Message ----- 
> From: "Jason Stone"
>
>  We use panelized 2x6 16" o.c. construction one some of our homes and are 
> very pleased with the result, though we end up using more lumber than we'd 
> like. The timing of your post is interesting since I was researching OVE 
> this week to see if we couldn't reduce our material usage.  Has anyone else 
> actually built with advance framing techniques -- in particular 2x6 with 24" 
> o.c. in the Midwest?  I've run into polite resistance from my engineer, 
> green reviewers, architect, and carpenters because of concerns about 
> structural intergrity (specifically, what I understand to be a 90 MPH wind 
> rating requirement, which in turn requires a high cost sheathing that 
> offsets any OVE savings).
>
>  Jason Stone
> Sage Homebuilders, LLC
> St. Louis, MO
>
>
> We've been using 2x6 - 24" o.c. for I can't remember how long. We use 
> polyurethane to glue all of the sheating to the studs, walls and roof. 
2x6 on 24" spacing is in the International Building Code standards, so I 
can't understand why anyone would be resisting the system.
In B.C. we can only use the 2x6 construction for exterior walls, but 
spacing varies depending on point load requirements. A lot of the newer 
construction I've been working on pretty much looks like what is 
recommended in the Advanced Framing guides--except that we still used 
doubled top plates on walls.
The extra stud cavity depth is required to get the minimum required 
insulation levels in.
I haven't seen anyone glue the sheeting on, though. If you're concerned 
about off-gassing from the glue, you could skip the glue and use the new 
Hurriquake fasteners from Bostich/ Stanley, which are specially designed 
to withstand high wind and earthquake loads.
http://www.bostitch.com/xhtml/interactive_hurriquake/hurriquake_show.html
These nails don't appear to add that much more cost to a project over 
using ordinary air-nail spikes, especially if you're skipping the glue.

With occasional 90MPH wind loads, I'd think you'd also want to build 
using hurricane fasteners  to tie the roof trusses to the footings, 
"just in case. "

If you're building the wall assemblies on the floor and raising them you 
can also inset metal t-braces into the studs by cutting a diagonal slot 
for them with the circular saw then nailing things together before you 
fasten the sheathing.
With care, this will also help keep the wall assembly square as you 
raise it, so the extra time it takes to add the bracing should lessen 
the time spent squaring things up when the wall panel is raised.

With the deeper cavities, you could use Roxul rockwool insulation batts 
and end up with about R-22.5 in the walls. The rockwool also has some 
other advantages--the stiffer batts won't sag if they do get wet, and 
don't seem to promote mold grow on them like fiberglass does.  Local 
availability from your suppliers might be a problem, though.

There's an Advance Wall Framing guide available at this link and it's 
worth looking at, and forwarding to the naysayers:
<www.eere.energy.gov/buildings/info/documents/pdfs/26449.pdf>http://www.eere.energy.gov/buildings/info/documents/pdfs/26449.pdf

I think there was also at least one article about this in Fine 
Homebuilding some years ago.
> <snip>
>
> Stick to your guns, don't let those who are stuck in their old ways take you 
> down with them.
>   
Agreed.

Cheers,

Chris Green.