Swedish Food for thought
I find the construction details at this website to be very interesting….
http://blog.lamidesign.com/2011/06/untitled-1.html
any comments?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
This link includes "good, better & best" details
http://blog.lamidesign.com/search/label/USA%20New%20Wall
john,
i've been following greg's blog on the swedish pre-fab stuff for a while, there are definitely some gems in there.
i'm interested in using a spinoff of this wall for a series of panelized passivhaus projects underway. the interior air barrier is in correct location, but we're not comfortable w/ a membrane so we'll probably have to slide structural sheathing inboard of 2x (hopefully 6, not 8...) which probably has some implications we'll need to work out w/ structural and GC.
also, i'm slightly against the use of mineral wool at this point, due to the formaldehyde content (1-6%), but for rainscreens in the NW... it might not be a bad idea.
I agree with Armando post #57
https://www.greenbuildingadvisor.com/blogs/dept/green-building-curmudgeon/it-time-stop-insulating?page=1&cm_BN%24V3gB7W8pUB8buxxDiDDMa_B7W8pUHUh-0=1308190084
Swedish Platform Framing is probably not a good fit for "the South".
And it is probably Not-So-Affordable for Custom(one of a kind) homes in many other parts of the US.
Swedish style does look like a good(not-so-foamy) and more durable alternative to SIP for modular Off-Site construction.
For affordable/buildable ceiling assemblies ... I think a vented attic with a good air barrier at the ceiling combined with Cellulose "galore" is the way to go.
Affordable/Buildable (Not-so-foamy) Walls are not-so-easy
For Wall Assemblies(in any cooling climate) I think an airtight exterior structural sheathing should be the starting point.
The framing needs a thermal break ... either double framing or cross-hatch.
For insulation I think the two most promising(not-so-foamy) options are densepack cellulose or Mineral Wool Batts.
Why not Mineral Wool Batts?
I would like to hear more (good & bad) about Mineral Wool Batts.
Mineral Wool vs. Cellulose:
I have this opinion for the reason that the Swedes don't use cellulose insulation in their prefab wall assemblies. They don't like it because it's heavier than mineral wool (therefore more expensive to ship), and it would settle during shipment. I haven't seen anything to verify this assertion. Cellulose is a lot greener to manufacture, that's a cinch.
Very interesting article. We recently completed off-site panelization of a balloon framed house with many of these strategies. Assembly was very efficient. We added an insulated 2x4 service cavity at the interior with our vapour retarder against the interior of the outer structural wall. With only a handful penetrations through our control layers we managed excellent blower door numbers and our MEP subs could complete their rough-ins without having to reinvent their process.