[Greenbuilding] [BULK] Re: [BULK] Re: VIroc

[Chris Green]

Keith Winston wrote:
> That's interesting. Now, that problem will be partly true of any 
> tightly-installed exterior foam board insulation, it seems to me. 
> Chris's inspector-generated idea of drilling the back plane doesn't seem 
> likely to improve things in my mind too much, if the foam is installed 
> tightly against the building: 
Ah, the mysteries of dealing with inspectors. Just treat them like the 
gods they are...:-) And volunteer no information...
> it could take as long for moisture to 
> migrate to a hole as through the OSB...
>   
We used ply, actually. I think they expect the moisture to travel 
through the insulation inside the cavities, not through the wood. Any 
moisture that does make it to the wood will have a chance to escape back 
into the cavities. And since there will be a small difference in temps 
between the floor and ceiling regions, and heat rises, I would guess 
their thinking is that the rising air will pull the moisture up with it 
since warmer air contains more moisture than cold.
> What about if an EIFS-like system was installed on a breathable 
> sheathing (maybe Chris's swiss-cheese OSB -- hey Chris, we've got a job 
> for you!), with a breathable exterior finish...
>   
$45/ hour, living out allowance to cover the hotel room and meals, and I 
get to keep the big horse power drill, and any forstner bits I don't 
destroy.... :-)
Actually, I just started a new job today. And I must have done okay 
because they said I could come back tomorrow.
> But why is this that different from SIPS, now that I think about it? 
>   
I described these as site-built SIPs a few times.
> Does the synthetic stucco breath that much less than OSB? Probably so, 
> as I think about it. 
I have been told, or read, some stucco mixes contain acrylic admixtures 
to make them "waterproof."

I do hope someone starts stocking real lime plaster in my area soon. I 
want to start working with it.

I'd never heard of EIFS before Lawrence mentioned it. The whole idea 
reminds me of  or wearing rubber gloves in the summertime. After a while 
your skin gets wrinkled because the moisture can't escape.

Cheers,

Chris Green.