Insulation of Renovated Addition – Insulation Inspection
Hello Breaktime,
Insulating 2×6 wall cavities and 2×8 ceiling bays of an addition renovation I “sandwiched” Pex piping used for hot and cold water supply, and HWBB heating supply with batt insulation, thus having the piping covered by the insulation Kraft facing. During my insulation inspection this morning, the inspector indicated he wanted to see the piping exposed and on the surface of the Kraft facing. However, he still signed off on the insulation work. I am considering taking his suggestion with a grain of salt. Why? Because the piping runs in some places are 2 1/2 ” inside the wall ceiling space. It seems to me that exposing the piping by slicing the Kraft paper and compresing the insulation behind the piping reduces R value in that particular cavity/bay. Also, all the Pex piping is wrapped in Armor-Flex. Another reason is that sheet rock installation starts tomorrow! FYI Insulation is wall cavities is R-19 and ceiling bays either R-30 or R-22.
We have been experiencing record cold here in Northern NJ and the piping has been fine the past one month plus that it has been behind the insulatioin. The construction area has been as cold as mid 40s with temporary HWBB heating on full time. Roof is covered with snow and gutter ice damed.
Should I get busy now exposing pipes at this late stage of the game??
Thanks all,
Geoman
Replies
Geo
Your call..
but, 43 yrs of observation of frozen pipes and the corrective measures afterwards suggests strongly that you never insulate piping from a heat source in walls.
Not familiar with armor flex, so maybe that's a qualifier.
currently your piping is above freezing with the heat on and not air sealed by the wallboard.
Best of luck.
get busy...
pex will more than likely never bust on you but your lines will freeze and you wont have running water wherever they do freeze. you are isolating your pipes to the unconditioned side of you insulation.
I would strongly suggest you follow his advice. If you feel that you're compromising the insulation too much you can slit it and then work a piece of foam (which generally has about twice the R per inch of FG) behind the pipe, in place of the FG. Just be sure to NOT insulate the interior side of the pipe.