[Greenbuilding] Exterior insulation retrofit

[Sam Ewbank]

Jason,
I was assuming that Bill was going to blow cellulose insulation in from the
exterior likely by drilling holes in the wall and inserting a nozzle.  It
would be nice if Roxul made  a blow-in product similar to cellulose.  I am
interested in using Roxul in place of styrofoam or Poly Iso (can't say
styrofoam now without thinking of Mr. Rob Tom's "plast-ecchh!") and the
local Orange  box store in my area has Roxul products available via special
order.   Would you recommend using the Roxul "Drainboard" product over the
Cavity Rock where battens/furring strips are going to be installed for a
rain screen siding application?

Bill, if you are going to leave the sheathing on make sure you get a good
contractor for installing the cellulose since you can easily have voids in
the wall from wiring and settling or as in the case of the house I live in
balloon framing open to the crawl space. Most rental blowers are under
powered to get a good density.  If you are taking the sheathing off than you
are open to more possibilities.
My preference on the one project I have done is to put the weather resistive
barrier over the sheathing so all the penetrations can be detailed properly
prior to the rigid insulation being installed.  I know this is what Martin
Holladay @ Green Building Advisor likes to call a "Belt and Suspenders"
approach since a wrb is not really necessary with foam.  Attention to detail
at all the penetrations and joints can't be stressed enough.
I would be curious to see your approach for the shingle siding installation
if you are using a rain screen.  It seems to me you would need to add
vertical furring strips and then horizontal strips at the nailing schedule
heights.  I have a project in the works where I would be installing board
and batten siding and figure  I would need to do something similar.
Alternative siding source would be to find a building materials re-use store
or salvage. Some Habitat chapters have a "Re-store" retail outlet or
something like Samuel Mockbee, who used some 80 Chevy Caprice windshields
purchased for $80 to do a glass facade of a building.
www.flickr.com/photos/
g_agnew/1393757857/<http://www.flickr.com/photos/g_agnew/1393757857/>

Best of Luck

Sam




On Thu, Apr 28, 2011 at 10:10 AM, Jason Holstine <jason at amicusgreen.com>wrote:

>  Bill,
>
>
> On 4/28/11 8:45 AM, "bill.allen at verizon.net" <bill.allen at verizon.net>
> wrote:
>
> Hi all,
>
> I am researching a project for my single family home. Classic 1926 stick
> construction. Zero insulation in the walls...time yet again for an external
> paint job. Would really appreciate comments on the following plan:
>
> We never want to paint again...are thinking of natural cedar shingle
> siding, maybe with preservative but otherwise left natural.  Don't like the
> embodied energy in the various cement siding solutions....alternatives?
>
> While the siding is down, fill the wall cavities with cellulous from the
> outside.
>
> Replace original double hung windows with new construction insulated, R-5
> if we can afford it, windows mounted "innie" on the plane of the original
> dimensional 1x lumber t+g sheathing.
>
> Add external insulation....rigid styrofoam.  Since there is no interior
> vapor barrier (plaster on wood lathe), I am worried about the dew point
> ending up in the center of the wall...therefore, per the building science
> article, add 4" of styrofoam to the outside to keep the dew point external
> of the sheathing.
>
> Will require careful details at windows and other penetrations.
>
> Big job...has anyone done this?  Any comments on any part of the above
> would be most welcomed.
>
> Thanks,
> Bill
> _______________________________________________
> Greenbuilding mailing list
> to Send a Message to the list, use the email address
> Greenbuilding at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org
>
>
> _______________________________________________
> Greenbuilding mailing list
> to Send a Message to the list, use the email address
> Greenbuilding at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/greenbuilding_lists.bioenergylists.org/attachments/20110428/13a1ef7a/attachment.html>