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Old 10-17-14, 05:34 PM   #48
AC_Hacker
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Quote:
Originally Posted by Daox View Post
Any updates on the floor insulation work?
Yes, updates for sure...

Phase 1 is complete, which is installing the 2" EPS layers under the floor, as per this diagram:



Overall, this involved:
  • Installing vapor barrier on ground and part way up the foundation stem walls.
  • Installing 1/2" spacer strips next to floor joists.
  • Fitting 2" EPS rigid insulation board.
  • Sealing all cracks between EPS & wood and EPS & EPS with 1-part foam sealer.
  • Sealing all potential air leak areas above the sill plate and below the floor structure with EPS & 1-part foam.









Before, I had only sub-floor & floor which gave me an abysmal
  • Floor & subfloor = R-1.5
  • Inside air film = R-0.68
  • outside air film = R-0.17
TOTAL = R-2.35


Now, I calculate:
  • Inside air film above floor = R-0.68
  • Floor & subfloor = R-1.5
  • Inside air film below flooring = R-0.68
  • R value of 1/2" air space = R-1
  • Inside air film above EPS (one surface reflective) = R-2.23
  • Two inches EPS = R-4/in or R-8 total
  • Outside air film below EPS = R-0.17
TOTAL = 14.26 - 18% = R-12

[NOTE: the final value has been reduced by 18% due to thermal bridging.]

At this point I should be OK for the winter... at least it's way better than it was for the past 122 years.

I gotta say, it doesn't feel like a dank nasty crawl space any more, more like a room... not that I am tempted to spend any leisure time in there!

Best,

-AC
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Last edited by AC_Hacker; 10-25-14 at 01:10 PM..
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