[Greenbuilding] Polyurethane door cutouts underslab, and exterior below grade?

[Chris Green]

Clarke Olsen wrote:
>    A nice system for footings, made by I don't remember, uses a plastic
>    sheet, stapled to 1 x 3's on stakes to form the footing. Not only do
>    not have a stack of 2 x 10's with concrete on them (even the 1 x 3's
>    stay clean), but you now have moisture barrier/thermal break under
>    your footing.
>   
That would be the products from Fab-form: Having used these I can 
personally recommend them, especially when you are faced with building 
footings on top of an uneven surface like the ones you'll get it you dig 
your basement hole in rock.
Been there, done that: it's hard to backfill around footings using 
fractured rock, and takes time better spent elsewhere, or you have to 
pay to haul in crush to do this.

The forms save a lot of time that would otherwise be spent 
scribe-fitting footing forms to the surface.
Watch the how-to-use  videos at this site a couple of times, and use 
lots of staples.

http://www.fab-form.com/

Engineers and building inspectors who are unfamiliar with this system 
will want to know that the bottom of the forms is at least as wide as 
the figure called for in the blueprints, so you add twice the depth of 
the footings and the width together, then an extra length to determine 
which set of lines on the fabric to use. You want to have a bulge that 
looks a bit like a radial tire profile.
The extra width beyond what is used inside the footings is left on the 
outside of the forms and later run up the foundation walls to add an 
extra bit of moisture barrier to the foundation.
One of the pdfs at this site has a drawing explaining this in pictures.
 
The fabric is left in place when the wood holding it is removed, and 
becomes a barrier that will prevent a lot of moisture being wicked 
upwards by the concrete and pulled inside the building.

I would prefer to use 2x4's for the footings, but if you're going to use 
1x's, you'll need to use a lot more stakes or steel pegs pounded into 
the ground.

An alternative to buying the fabric would be to collect a lot of lumber 
wrap tarps and use them, since most of these will end up in a landfill. 
This recycling can be cost effective both for the DIY'er, or if you're 
paying workers to do this work, since the fabric rolls cost about a 
dollar a foot--it's either $120 for a 150 foot roll or $150 for a 120 
foot roll.

I also carry a drywaller's or painter's scraper in my tool pouch to 
clean re-usable form wood off, and make it a policy of denailing and 
salvaging anything over 2', (or over 14 1/2" if we happen to be using 
16" stud spacings somewhere in the building. ) Saving and re-using 4- 2' 
pieces is the same as not buying and using one 8' board.

Cheers,

Chris Green.