What is the best way to insulate a central supporting post?
We are building a "High performance" 30'x34' house in northern NH. R32 ICF foundation in place and capped . R30 subslab 25 PSI XPS in place. Unfortunately builder placed a central steel/concrete filled lolly column (supporting post) for the 34' beam of the subfloor down the center penetrating the 6" XPS to a central footer. Not sure how much of an issue this is but worried about this penetration. Slab not yet poured. Put on hold to consider alternatives.
We have a number of options:
a) wrap the post in R20-R30 which is the present plan. (the top of the post is attached and therefore is cannot be entirely wrapped)
b) pull the central post and replace the some of the foam with 60 PSI or similar and replace the post (requires significant work and builder not confident point load of post on even 60 PSI foam won't sag) and reinforce concrete under the post.
c) pull the post, jag hammer some of the footer to dig deeper, pour 8" concrete slab in central area and add rebar under the post for structural integrity.... Will likely only get R20 in a central section of the slab in that case... (again @ 1/2 days extra work)
Experience with supporting posts centrally (this is the only on across the 34' span)
Posted Dec 12, 2012 8:39 AM ET
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