Re: [Ekodum] OSB or Not?

[Max Vittrup Jensen <max AT permalot.org>]

Thank you Daniel for the OSB interest, and Tomas for mailing the link.

Considering the strong influence Austrian SB building approach has had 
on Brotanek/Passive house institute, and thereby on Czech SB building in 
general, then I would really appreciate if some of you ekodum-list 
readers (with an interest in this topic), would make a Czech version of 
some of the facts mentioned?

I'm afraid I need to point out that there's not a black/white answer. 
Later on in the discussion someone mentioned that some OSB's were glued 
with Polyurethan instead. When I look at the data from the new Czech 
producer (Kronospan?), I'm not able to find out for myself what is in 
the product; maybe some of you can?

I see many problematic issues with OSB, especially with SB walls:
-Vapor diffusion not being as theoretical knowledge suggest, allowing 
fungi to grow on the boards
-OSB is very succeptible to fungi growth
-60% of OSB sold in Europe comes from rain forest.
-OSB is made in big factories, often transported far: High embodied energy
-At end of life cycle: How can you recycle it, if it's a concentrated 
mix of wood and polyurethan?

That said, I have to admit that the project for our new educational 
center includes Czech 'healthy'(?) (ventilated) OSB under the green 
roof!  Simply because of the time needed to cover such a large area vs. 
the risk of the old house underneath getting wet. +The problem that if 
we used local made boards from nearby sawmills, the boards are of 
slightly different thickness, different length and un-planed, which 
gives a high risk of penetrating the membrane, which will cover the 
roof, under the green roof.

In other words, somewhat a case of: "Morale is good, double morale 
double as good!"

Zdravim,
Ing. Max Vittrup Jensen
"Jen-Sen: Make it Reality"
Consultancy in sustainable engineering, planning and environment
585 15 20 10 - www.jen-sen.cz
------
PermaLot Centre of Natural Building
www.permalot.org
Czech Republic