# Replace Wall Insulation??



## SPS-1 (Oct 21, 2008)

Sure, going to a higher R value will help. Extruded polystyrene or sprayed-in closed cell poyurethane foam will likely have higher R value. Do you know what you have now? The spray foam has the added advantage that it will make the wall air-tight. As usual however, the good stuff is not cheap. You will have a hard time justifying the cost of replacing all the insulation for a small savings in heating cost. But then, some people just hate the thought of wasting energy to heat the great outdoors, and payback is not the prime motivator. Where are you located?


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## gregzoll (Dec 25, 2006)

Keep in mind for proper energy efficency, you need to seal any gaps along the sill and top plates, windows & doors, install E rated doors & Windows, have proper air exchange, due to you making the home tighter and more efficient. Also you would need to seal around any outlets, light switch boxes, lighting fixtures attached to the ceiling, insulate the attic and give proper air flow.

Then you have the attic or crawl space, and attached garage. Just adding new insulation into the walls is not going to make it more efficient. Oh, also since you have now opened the walls, most areas require that you now bring the electrical wiring up to proper code, install afci breakers into living rooms, bedrooms; gfci breakers in bath's, kitchen's, basements, garages, crawl spaces, outside outlets.

You pretty much have opened up a huge can of worms, when you opened the walls. That is why most choose to just retro insulate homes, by just cutting openings along each joist bay, and either using foam to fill in the gaps that the fiberglass does not fill, or compressed blown in.


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## Mstrlucky74 (Jan 19, 2013)

gregzoll said:


> Keep in mind for proper energy efficency, you need to seal any gaps along the sill and top plates, windows & doors, install E rated doors & Windows, have proper air exchange, due to you making the home tighter and more efficient. Also you would need to seal around any outlets, light switch boxes, lighting fixtures attached to the ceiling, insulate the attic and give proper air flow.
> 
> Then you have the attic or crawl space, and attached garage. Just adding new insulation into the walls is not going to make it more efficient. Oh, also since you have now opened the walls, most areas require that you now bring the electrical wiring up to proper code, install afci breakers into living rooms, bedrooms; gfci breakers in bath's, kitchen's, basements, garages, crawl spaces, outside outlets.
> 
> You pretty much have opened up a huge can of worms, when you opened the walls. That is why most choose to just retro insulate homes, by just cutting openings along each joist bay, and either using foam to fill in the gaps that the fiberglass does not fill, or compressed blown in.


Opened a huge can of worms...hmmm. We did not remove the Sheetrock to insulate... Much of the tape job, corner bead and other areas were bad


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## gregzoll (Dec 25, 2006)

Mstrlucky74 said:


> Opened a huge can of worms...hmmm. We did not remove the Sheetrock to insulate... Much of the tape job, corner bead and other areas were bad


Guessing then that you did not post this "We are taking all the sheetrock in our living room and wanted to replace the insulation to make it more energy efficient. Is there things we should look for to determine whether or not it will make a difference? I guess going to a higher R value will make a difference. Thanks."


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## Mstrlucky74 (Jan 19, 2013)

gregzoll said:


> Guessing then that you did not post this "We are taking all the sheetrock in our living room and wanted to replace the insulation to make it more energy efficient. Is there things we should look for to determine whether or not it will make a difference? I guess going to a higher R value will make a difference. Thanks."


R7 in the walls


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## Gary in WA (Mar 11, 2009)

Replacing your older R-7 (low density) with R-13 (medium density) will help some. Upping to R-15 in that 3-1/2" space after caulking all sheathing/plate/stud joints against infiltrating/exfiltrating air flow will help more. Using Roxul (R-15) will help even more and air-sealing the drywall after a vapor retarder (if in a heating climate) like CT's"Membrain"; http://www.bestofbuildingscience.com/pdf/Brainy membrane HEM_23-4_p37-40.pdf

http://www.buildingscience.com/documents/information-sheets/air-barriers-airtight-drywall-approach/
Describe the wall make-up and your location...

Gary


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## Mstrlucky74 (Jan 19, 2013)

Gary in WA said:


> Replacing your older R-7 (low density) with R-13 (medium density) will help some. Upping to R-15 in that 3-1/2" space after caulking all sheathing/plate/stud joints against infiltrating/exfiltrating air flow will help more. Using Roxul (R-15) will help even more and air-sealing the drywall after a vapor retarder (if in a heating climate) like CT's"Membrain"; http://www.bestofbuildingscience.com/pdf/Brainy membrane HEM_23-4_p37-40.pdf
> 
> http://www.buildingscience.com/documents/information-sheets/air-barriers-airtight-drywall-approach/
> Describe the wall make-up and your location...
> ...


Drying to determine if it is worth the trouble and $$ to take all this out and replace it with R15


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## gregzoll (Dec 25, 2006)

You really need to update your location at http://www.diychatroom.com/profile.php?do=editprofile and put the info in "Additional Details". As for replacing that R-7, yes, it will save you money over time as we have already stated. Plus because you have opened up the walls, now is the time to update the wiring, pull Cat-5e or Cat-6 for telephone & ethernet, and coax to those locations that tv's, telephones, computer equipment will be located at. Also gives you the ability to look for any rot or mold from water intrusion.

Also because of this work, have you checked to make sure that you do not need any permits.


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## Mstrlucky74 (Jan 19, 2013)

gregzoll said:


> You really need to update your location at http://www.diychatroom.com/profile.php?do=editprofile and put the info in "Additional Details". As for replacing that R-7, yes, it will save you money over time as we have already stated. Plus because you have opened up the walls, now is the time to update the wiring, pull Cat-5e or Cat-6 for telephone & ethernet, and coax to those locations that tv's, telephones, computer equipment will be located at. Also gives you the ability to look for any rot or mold from water intrusion.
> 
> Also because of this work, have you checked to make sure that you do not need any permits.


Pulling all my wires, speaker, cat 6 etc. What is coaxial used for besides from out of the wall to a cable box? Thanks


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## joecaption (Nov 30, 2011)

http://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table


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## gregzoll (Dec 25, 2006)

Mstrlucky74 said:


> Pulling all my wires, speaker, cat 6 etc. What is coaxial used for besides from out of the wall to a cable box? Thanks


Component cable for video, audio, satellite tv, Over The Air antenna, also can be used for HDMI in certain circumstances, same as Cat5e/6. You would be surprised at what the wires are used for, besides just what you think as being only catv.


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## Gary in WA (Mar 11, 2009)

The reduction to heat (of the product in perfect conditions/installation) flow right now is about 90%. Changing to R-13 would give you only 3% better, chart on pp 2; http://www.enersavesystems.com/pdf/Economic-Thickness-of-Thermal-Insulation.pdf

BUT, that is if there wasn't a gap (1-1/2"+) split in front or back of the existing- 2-1/4" thick compared to 3-1/2" thick = no convective looping around it. The face paper requires full contact with the drywall, not with the gaps you show, or expect 50% loss, pp 35-51; http://www.buildingscienceconsultin...010-03-10_When_R-Value_Doesn t_Measure_Up.pdf The existing is too thin for the cavity, even when first installed...

IMO, add some 1/2" EXP strips to the studs for a thermal break to increase the whole wall R-value, pp. 39, that link.

Gary


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