My walls have been furred out with 2-by's but because the old studs actually measure 4" or more (and in some places were furred out previously, for whatever reason) they are much thicker than the 5.5" R-22 mineral wool batts that are going in them. In some places there's more than an inch of air space between the batt and the vapour barrier.
Manufacturer's instructions say "Ensure the surface of each batt is flush with the interior surface of the studs" but doesn't really say what happens if you don't.
Big problem? Am I decreasing my R-value from the nominal R-22, or am I just losing an opportunity to gain a few more R's?
I presume the only fix is to fillet extra batts to the right thickness and put them in, and that leaving the space at the outer wall is as bad, or worse...
Thanks,
Chip C Toronto