# Should I add insulation to my walls?



## derekeh (Apr 21, 2016)

I had to repair a small section of drywall in my house so I inspected how the walls were insulated. The walls are framed out of 2x8 lumber with the bottom plate being screwed to the concrete flooring in the house. The insulation is r19 with the vapor barrier on the inside wall. This leaves a gap of a couple inches between the insulation and the chipboard. After that is housewrap and vinyl siding. In the winter months, the house feels cold even though it may be 68 inside. I can feel air coming in around plugins as well. I have been contemplating removing my siding and chipboard so I can add maybe some r11 to the outside. Should I do this? Or is the air gap a good thing in the wall? Also should I put a vapor barrier underneath the chipboard as well? Thanks. 

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## Windows on Wash (Aug 30, 2011)

Where is the home?

If you are going to pull the siding, there is a bunch you can do from outside. How did the exterior sheathing look from the inside? 

2x8 walls? Interesting.


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## derekeh (Apr 21, 2016)

Located in southern Kentucky. The sheathing is in good condition. I had part of the siding off before when I replaced a door. As far as the 2x8 walls, the exterior walls used to be log. The logs were not maintained well and we're replaced. 

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## Windows on Wash (Aug 30, 2011)

Not sure that you need to remove the wood here then. 

No vapor barrier on the exterior as the wall needs to dry in one direction or the other. 

I theory, you could drill and fill from the exterior, but you will probably have to compress the existing insulation to get proper and dependable fills. 

Short of that, you can definitely air seal the exterior sheathing and clad it in some rigid foam to help with the thermal part of the equation. 

The thing that you will need to consider is that you will likely need 2" of rigid foam to the exterior as compared to 1" given your significant wall depth and what will likely be your outside framing edge temperatures. 

https://energycode.pnl.gov/EnergyCodeReqs/?state=Kentucky

http://www.greenbuildingadvisor.com...lating-minimum-thickness-rigid-foam-sheathing


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## derekeh (Apr 21, 2016)

Installing 2 inches of foam over the chipboard is more work than i can do at this point. I would have to reinstall all of my windows and also i have an upstairs deck to deal with. Maybe another time i can tackle it but right now its a no can do :/

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## Gary in WA (Mar 11, 2009)

Welcome to the forums!

" I can feel air coming in around plugins as well. I have been contemplating removing my siding and chipboard so I can add maybe some r11 to the outside. Should I do this? Or is the air gap a good thing in the wall? Also should I put a vapor barrier underneath the chipboard as well?"------------- pull the sheathing a panel at a time, add some unfaced R-13 FG (compressed is fine)- even fire-foam in a can around the electrical boxes/wiring-plumbing holes in top/bottom plates if you want- ADA the sheathing... or add another housewrap to air seal. Imperative to stop the convective looping from that gap next to sheathing robbing you of about 60% rated R-value now- plus the house condition air feeding it. 

No foamboard with your vapor barrier as is... possibly-- if only asphalt faced FG- but foamboard is not even recommended per code or BSC for climate less than Zone 5- especially 2"- imagine the cost compared to adding more FG...; http://buildingscience.com/document...ulating-sheathing-vapor-retarder-requirements. 

Gary


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## Windows on Wash (Aug 30, 2011)

Good catch Gary. Should have specified what type of foam in this case if you go that route. 

See the previous remarks about exterior vapor barrier. 

Plenty of sheet EPS foams are available that will give you all the perm rating that you need to maintain the walls ability to dry out. I agree that is is probably overkill given the climate, but the fact that there will be nearly R-26 in the wall means that they outside edge of that sheathing is going to be ice cold. If there is any moisture in that wall system, it will far more likely to condense on a supremely cold framing edge. 

Couple that with an airtight exterior sheathing and that moisture can't as readily move to outside. 

Something to keep in mind.


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## derekeh (Apr 21, 2016)

Alright so i shpuld add r13 faceless fiberglass insulation to my walls. Im a little lost after that though. What do you mean by ada the sheathing? 

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## Gary in WA (Mar 11, 2009)

"Plenty of sheet EPS foams are available that will give you all the perm rating that you need to maintain the walls ability to dry out. I agree that is is probably overkill given the climate, but the fact that there will be nearly R-26 in the wall means that they outside edge of that sheathing is going to be ice cold. If there is any moisture in that wall system, it will far more likely to condense on a supremely cold framing edge."----- -- -----not with his interior vapor barrier... *1/2" foamboard (R-2.5) *for his climate to prevent condensation is not worth the work involved and still have a big gap to the sheathing inside the cavity. 
"Couple that with an airtight exterior sheathing and that moisture can't as readily move to outside."--- ---- ---- VB on inside and air seal with WRB OR panels ADA, I really doubt he will worry about moisture... air seal is totally different than a vapor barrier; http://buildingscience.com/documents/reports/rr-0004-air-barriers-vs-vapor-barriers/view

ADA; caulk the wood framing to sheathing, at least at perimeter. http://www.buildingscience.com/documents/information-sheets/air-barriers-airtight-drywall-approach/

Gary


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## Windows on Wash (Aug 30, 2011)

That's all fine and true Gary, but in order to have ADA in this case, please explain to him that he is going to need to remove all of the sheathing as well as most of the insulation to expose the backside of the drywall so that he can air seal every penetration as well as the bottom and top plates. 

How do you plan on doing that if the room side insulation is installed via stud stapled flanges?

Sounds great in practice, but it will be an undertaking to remove all of that insulation to get to ADA standards. As we both know, any small gaps and air movement in that insulation will move a bunch more moisture through it as compared to diffusion. 

derekeh....keep in mine that when you remove all of that sheathing as well, you are going to be torquing on that wall a good bit. Be prepared for some drywall cracks on the interior surface to touch up.


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## Gary in WA (Mar 11, 2009)

Windows on Wash said:


> That's all fine and true Gary, but in order to have ADA in this case, please explain to him that he is going to need to remove all of the sheathing as well as most of the insulation to expose the backside of the drywall so that he can air seal every penetration as well as the bottom and top plates. -------- I stated to ADA the SHEATHING, not the drywall. I said to locate the electrical and cut through the insulation/asphalt paper to canned foam around it and the wire hole through the plate- follow the wire...
> 
> How do you plan on doing that if the room side insulation is installed via stud stapled flanges?
> 
> ...


--------- first, if you use a nail puller and remove the nails- one at a time, the sheathing will fall off. Removing one nail at a time doesn't shake the wall enough to cause a drywall crack, in fact- I have never ever seen drywall crack, except before installation to a wall/ceiling- or a tree. Plaster will crack but usually it is keyed in so well you can remove one whole side of an interior wall and not even harm the other side's plaster finish. With drywall, you may get a fastener pop but that is far different than a "crack". Actual remodeling experience (years) is very helpful in answering a lot of questions. I'm sure Erik can answer some window questions better than I could... Gary


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## Gary in WA (Mar 11, 2009)

You could also add some roll insulation used under vinyl siding (closed cell, R-2, or R-3----- 4.5 perms) before the WRB to air seal rather than caulk all the sheathing perimeter... just tape the seams.

Gary


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## Windows on Wash (Aug 30, 2011)

Thanks for the uber secret tool tip about the nail puller. Sounds fancy. 

Without knowing how and what was used to attach the framing, to claim that you may not impact the interior wall finishing is probably foolish. 2x8s will be much more deflection resistant here than standard 2x4 framing, but if they attached the framing with some long'ish framing nails, even using a magical nail puller will create some wall stresses. 

We even discuss this potential with clients when we are pulling siding with 1.5" nails in it. You won't typically have any large issues in the open areas of the drywall, but you can get nail pops and areas around window trim and jamb extensions are more prevalent. 

Seeing as more air leakage, on average, comes from the cumulative areas of top and bottom plate gaps and seals, I will stick to my original concerns regardless of fishing through every wire and electrical outlet box. You are going to spend a good bit of time pulling off each piece of sheathing and sorting through all the insulation for every penetration, wire, and envelope breach. 

I would recommend that you get puddy pads for the back of the boxes as they are more inert than foam here and will probably be easier to put on and get tight. You can order them online from Hilti or other places. Most contractors withexperience and that do this type of work know about those things. 

Good luck with it. Sounds like a pretty good project by the time you pull the stuff but hopefully you can segment it out and just work down the walls in order.


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## derekeh (Apr 21, 2016)

Im not too concerned with the drywall. If it cracks then i will fix it. I have 3 walls i want to work on. The other wall has a garage on the outside of it so its not much of an issue. Im confident that i can finish a wall in a day. I would like to do the back wall of my house first as it seems the worst as far as feeling air around recepticles and such. It also happens to be the shortest wall. I dont think sealing around outlet boxes and wiring will be that bad. Im still unsure if i should add insulation or not though. 

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## Gary in WA (Mar 11, 2009)

Windows on Wash said:


> Thanks for the uber secret tool tip about the nail puller. Sounds fancy. --------------- actually, it took me about 5 years to find the best nail puller, while I used many, many inferior ones during 27 years of framing houses and 7 years of remodeling.
> 
> Without knowing how and what was used to attach the framing, to claim that you may not impact the interior wall finishing is probably foolish. 2x8s will be much more deflection resistant here than standard 2x4 framing, but if they attached the framing with some long'ish framing nails, even using a magical nail puller will create some wall stresses.--------------- the *framing *should be attached with "longish" nails, it is the *sheathing* that would require only 2" or max. 2-1/2" nails. Surprised you don't know the terminology.
> "*TABLE R602.3(1)-continued FASTENER SCHEDULE FOR STRUCTURAL MEMBERS*
> ...


 --------------- I think they are called "*putty* pads", since it is putty on a sheet...; https://www.us.hilti.com/firestop-%26-fire-protection-systems/firestop-putties/r4559---------- for $143 plus shipping compared to $8 for a can of great stuff to do the same 20 outlets..... a no brainer- at least for me . And you need the foam anyway to fill the wire/plumbing holes or by more putty- minimum order is.... lol. Or a small house.

Gary
PS. Yes add the extra insulation to stop convective looping. Number/letter for rows each piece of siding on the backside as you remove it.


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## Gary in WA (Mar 11, 2009)

More tips and my cats-paw suggestion on sheathing replacement; http://www.diychatroom.com/f2/sliding-glass-door-flange-under-sheathing-403857/

Gary
PS. let us know if you have any problems...


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## derekeh (Apr 21, 2016)

I plan on starting this in a month or two. Hoprfully it makes fir a warmer house 

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