[Mstrlucky74]

We are tearing down all the Sheetrock walls on the 2nd floor and will be running new electric. I'm not sure what is behind the walls insulatiion wise but whether we think it is okay or put new insulation between all the studs is that all to be done? I saw a pic of plastic nailed to the studs covering the insulation. Is this typical? Thanks

 

[Mstrlucky74]

Jumped the gun..

http://www.thisoldhouse.com/toh/how-to/step/0,,20431068_20856780,00.html

 

[Gary in WA]

Your location would help...

Gary

 

[gregzoll]

Really do not understand why you need to gut the complete upstairs, unless you found out while pulling existing permits on the place, that a whole lot of corners were cut. BTW, if you replace electric in your place, you then have to bring it up to current codes, and that means AFCI for all areas specified by your AHJ & the NEC.

 

[Mstrlucky74]

Your location would help...

Gary

Long Island, NY

 

[Mstrlucky74]

Really do not understand why you need to gut the complete upstairs, unless you found out while pulling existing permits on the place, that a whole lot of corners were cut. BTW, if you replace electric in your place, you then have to bring it up to current codes, and that means AFCI for all areas specified by your AHJ & the NEC.

Our sheetrock is in bad shape and I cut a hole in one place and saw there was no insualation.

 

[gregzoll]

That makes better sense. While have the walls open, pull Cat-6 or cat-5e for telephone and/or network wiring, coax also. Also make sure you seal any holes in the walls, to help airseal between attic spaces, and the floors below.

 

[Gary in WA]

Cavity insulation requires air sealing of the cavity; https://docs.google.com/viewer?a=v&q=cache:23GL573L8rsJ:www.insulex.net/Links_files/Understanding%2520R-Value%2520-%2520Fine%2520Homebuilding.pdf+density+of+fiberglass+insulation+to+stop+convective+loops&hl=en&gl=us&pid=bl&srcid=ADGEESjB5jT6D-pmr_diIjOC-wZLxLcL4M5mbUnQEx_wbazuubbVf8rsdQ_J7E_qb_p6rK4lzPkaHsJJw_pncDyBqyCJUCz2zaxO3wozHJ5XSnommOF0XWF7o9tMOge2FIXRCxwhJgNT&sig=AHIEtbT0wgPl1yn5T5V8M8l_EeA2F-qvvA

Caulk the plates/studs/sheathing joints also, or expect a 40% heat loss due to air infiltration/exfiltration, when the wind blows outside. Contact the fibrous insulation batt with the drywall or expect a 300% loss, fig. 2a,3a; https://docs.google.com/viewer?a=v&...9EVKki&sig=AHIEtbTb5UnlVQ7Je0R-_NGatSVo3wzmAQ

Tips; http://oikos.com/library/insulating_framed_walls/index.html

http://www.advancedinsulationinc.com/resources/Getting_Quality_from_Fiberglass_Insulation.pdf

Air-seal the sheathing, page 21; http://www.engr.psu.edu/phrc/training/understandingbarriers.pdf

Simply adding more insulation rather than air sealing won't help much, pp.40: http://www.buildingscience.com/docu...mance-residential-buildings-all-climate-zones

ADA the drywall: http://www.buildingscience.com/documents/information-sheets/air-barriers-airtight-drywall-approach/

Many people don't understand that the air seal importance is equal to the insulation importance, or greater. Even local building codes are requiring it now- "between dis-similar materials- because they expand/contract differently; producing cracks/gaps for air in/out (with the air rides moisture);
"N1102.4.1 Building thermal envelope. The building thermal envelope shall be durably sealed to limit infiltration. The sealing methods between dissimilar materials shall allow for differential expansion and contraction. The following shall be caulked, gasketed, weatherstripped or otherwise sealed with an air barrier material, suitable film or solid material." Now read the list; http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_11_par035.htm

When fiberglass is tested for it's R-value = a closed, six-sided box with NO air leaks is used.... add some wood studs (R-1.5 per inch thickness) for a thermal loss and "heat sinks"; http://www.coloradoenergy.org/procorner/stuff/r-values.htm
Let me know if you need another tip for a warmer room...it takes a little more work, though.

Gary
PS. vapor barrier/retarder; http://www.buildingscience.com/docu...heet-310-vapor-control-layer-recommendations/