[GSBN] windscreen

[forum at lamaisonenpaille.com]

Interesting topic. Last year I saw a presentation from a french sb 
builder who uses 'compost fabric' (that one would pull over a compost 
pile) to protect his stacks of bales on the build and, if I rember 
correctly, he also uses it over his fresh plaster to have it protected 
while it dries.
Another material I've heard of is used by farmers. On certain 
structures, rather than building walls, they use screens that are open 
to air movement with normal windspeeds but when the wind blows harder 
they close up. I have no idea how esteaticly pleasing they can be.

Though I'm eagerly reading through the silanes and other 'miracle' 
additives I agree with RT's worry for cracks (and the jonction between 
plaster and protuding elements). I also wonder how long those products 
last, how one (homeowner) would judge when it is time for a new coating 
and how multiple coatings of who-knows-what aplied over the coming 
decades would blend.
That's why I've come to consider plastered SB somewhat like mini-skirts: 
Looks great, but offers little protection. I know for a fact that those 
sturdy dutch girls still wear 'em in winter, but some of them suffer the 
consequences.

Anyway, for some years I've pondered about the 'best' way to make a 
cladded SB wall and came to the folowing concept (that I intend to build 
this year): wood cladding (douglas fir), battens/vented airspace, AGEPAN 
DWD* boards, strawbales (placed vertically and pushed tightly against 
the boards), earth plaster. The posts (between the bales) would be 
placed at 40cm on center.
What I wonder is: as these AGEPAN DWD boards have a sd value of 0,2 m, 
would I get enough vapour barrier on the inside with a 5 cm straw-clay 
plaster? The golden rule says that the outside should be 5 times more 
open than the inside, but considering there is a vented rainscreen my 
gut feeling (or rather my desire) suggests that it should work. Anyone 
want to shoot this down (or confirm)?
*for those unfamiliar with these boards, they are structural and act as 
a drainage plane.
http://debelux.ahk.de/fileadmin/ahk_debelux/AHK_Projekte/Praesentationen_Energieeffizienz/Glunz_AG_01.pdf

André - it's hip to be square - de Bouter
France (ex-dutch)