[Strawbale] PEX feedback

[Chris Green]

Raftercat5 at aol.com wrote:
> <snip>You mentioned not to forget putting  that foam stuff under 
> it.  We did that on the place we're living in now,  but I've yet to figure out 
> what it's for! 
The foam or other vapour barrie/ membrane is placed there to prevent the 
wood from absorbing moisture which can migrate up through the concrete. 
This is usually a building code requirement, but if you have poly under 
the slab as well as rigid foam insulation, it's probably overkill.
>  It's blue foam and came in  rolls.  We put it under the wall 
> frames.  But, what is it  for?   If we go with the glue, should it go above 
> and below the  foam?  (confused here a bit...).
>   
Cut the foam a little narrower than the wall plate, or trim it after the 
wall is placed, and run the beads alongside it on both sides after the 
wall is placed and lined up straight.

Another way to lock the wall in place is to drill a small hole through 
the wall plate with a 3/16ths masonry bit and into the concrete a few 
inches then place 2 or 3 pieces of tie wire in the hole and drive in a 
3" nail. This is cheaper than buying the glue. Also, if you start at one 
end of the wall and "wire and nail" systematically every 3 or 4' as you 
go, you can straighten the plate out as you go, lining it up to match 
the chalk line you've snapped to show where the wall goes.

These are tricks used to do the '"backframing", installation of 
non-loadbearing walls in the basement.
 
For loadbearing walls, you will have previously built footings for these 
walls before doing the floor slab and stuff. This is probably why Jill's 
house had the walls placed before laying down the tubing and pouring the 
slab. Otherwise, it isn't necessary to have footings for 
non-load-bearing walls.
> <snip>  
> Jill, you said:  "We have pex in the concrete floor. We placed our  bottom 
> plates plates(for
> all walls) before we laid our pex."  Jill, How  did you do that?  What did 
> you connect your bottom plates onto if the  concrete wasn't poured yet? 
About chalkline chalk: use the red stuff. It sticks better, and shows up 
better. I had blue chalk and it wasn't quite up to snuff for most of the 
work I did these past few months.


Cheers,

Chris Green.