Question on insulting walkout basement for arcade build

animesuperj

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Question on insulting walkout basement for arcade build

I finally finished the construction on my walkout basement, and now need some help with the insulation. I've looked online, asked people, went to Home Depot; and can't figure out the proper way to do this.

I've attached some pics from google sketchup of how the room is layed out. The area with the OSB is the area I need insulated. This was the newly constructed area. That area is the only part of the room that is studded. The rest is underground. The wall that has the ramp is concrete brick, and the remaining two walls are fieldstone (the walls that don't have windows/doors on it).

Since it's a walkout, those are exterior walls; however the rest of the walls face the ground or the interior to the rest of the basement. With the studded walls being exterior, do I need to put a vapor barrier on them, the insulation? Put ridged foam, then insulation? This is the area that I'm confused. I eventually would like to drywall the studded area. I'm fine leaving the rest of the basement unfinished, because the fieldstone is a pain to really do anything with.

Also, the ramp leads up to the main level of the house. It's an odd layout, but it works. If anyone can help on proper procedure to complete this, that would be wonderful. I would love to continue working on this room to finish my arcade.
 

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Aaaaaand, I just realized I spelled 'insulating' wrong on the thread title, lol. I think that means it's time to go home from work.
 
If you buy craft faced fiberglass then you do not need a vapor barrier, that is what the paper is for. How thick is the wall, what size studs did you use? If you used 2x4 then you need R13 or R15 and if you used a 2x6 stud then you need R19. The only reason you would need the plastic vapior barrier is if you use unfaced insulation. There is a new product out that is supposts to be better to use then fiberglass, fiberglass sucks and makes you itch. It is made out of old jeans, it comes unfaced so you would need to put up plastic. It does cost more but for the small wall you are doing it might be worth it, I hate firerglass insulation it I can deal with the itch but breathing it in sucks.
 
I don't know if this pic helps or not. I insulated the walls when I built my gameroom above ground. SmityMike is right about probably not needing the vapor barrier if you use the paper backing. I considered doing it and was talked out of it because the walls need to be able to breathe and you don't want mildew due to moisture buildup. Keep in mind I'm in the south though. I'm not sure if it would be different in your area.
 

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I'd start out deciding which product is available in your area, then contact the manufacturer for installation guidelines. Most of them have good web resources that specify applications for your particular project.
 
This is gonna be a tough one as you've got a newly constructed fully exposed exterior wall that needs insulation and it joins with fieldstone walls in the front corners (at least in close proximity) that have minimal insulation value. You've got a bit of a blind corner scenario that will constantly be frosting over the winter because of the temp differences between the two walls. If you plan on heating this entire area, your best course of action would be to stud out the other 3 sides and insulate it all, this way you'll at least be conditioning the interior wall surfaces evenly.

State building code would tell you that conditioned spaces need to have insulated walls with a minimum of an R11 rating plus a vapor barrier, the barrier can be 4 mil. poly or faced insulation.
 
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This is gonna be a tough one as you've got a newly constructed fully exposed exterior wall that needs insulation and it joins with fieldstone walls in the front corners (at least in close proximity) that have minimal insulation value. You've got a bit of a blind corner scenario that will constantly be frosting over the winter because of the temp differences between the two walls. If you plan on heating this entire area, your best course of action would be to stud out the other 3 sides and insulate it all, this way you'll at least be conditioning the interior wall surfaces evenly.

State building code would tell you that conditioned spaces need to have insulated walls with a minimum of an R11 rating plus a vapor barrier, the barrier can be 4 mil. poly or faced insulation.

I was thinking the same thing, if the 2 side walls are partially exposed and not completely underground, stud them up and insulate them as well. You will not regret it later on
 
Never hurts to insulate and allowing everything to breathe is a very good idea. For moisture concerns, I run a dehumidifier and it keeps my basement nice and dry at the same humidity level year round. I have it set up to run into a floor drain so I never have to worry about emptying it.

Bill
 
Thanks for the tips everyone. I know this is a weird situation, because I'm dealing with three different types of materials for the walls: fieldstone, cinderblock and the wood.

The wood walls are completely exposed, and wrapped and sided on the outside. The fieldstone walls are actually all facing the interior of the house and are the walls to the other side of the basement; so those will probably be the temperature of the other side year round. The cinderblock wall (which is along the ramp) is the only wall that is partially exposed, due to the ramp. I know that would be easy enough to stud out and insulate, so I might do that. From what I've read, I'd just put rigid foam on the walls, and then stud in front of it.
 
Since you're thinking about using rigid foam, i'll throw in a couple more comments.

The best use of rigid foam is to place it on the outside of your walls prior to backfilling your foundation, this provides a good thermal barrier for our climate and helps keep the exterior walls from letting in the cold. You obviously don't have this option available since your foundation has long since been done so you're forced to place it inside which will still be effective if you choose the right stuff. Use the rigid 2" that has an R10 value, place it against your block wall and seal all the joints with a can of spray foam. By sealing everything up, you have now created your vapor barrier. Stud your walls out and batt them with an R11 unfaced insulation and proceed to drywall. I wouldn't put a layer of poly on the front face of the insulation or use a faced product at this point because you will now create a vapor lock/dewpoint in between the foam and the back side of your insulation which will eventually cause molding. If you're doing any electrical work, use old work electrical boxes that have no vapor gasket as well. Any moist air that does find its way into your wall cavities can seep through the electrical boxes and be eliminated by heat/ac or a dehumidifier once inside. Good luck, do it right and you'll avoid tearing out moldy walls in a few years.
 
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You could also use tyvek tape and not have the mess you could get with the spray foam.

Since you're thinking about using rigid foam, i'll throw in a couple more comments.

The best use of rigid foam is to place it on the outside of your walls prior to backfilling your foundation, this provides a good thermal barrier for our climate and helps keep the exterior walls from letting in the cold. You obviously don't have this option available since your foundation has long since been done so you're forced to place it inside which will still be effective if you choose the right stuff. Use the rigid 2" that has an R10 value, place it against your fieldstone wall and seal all the joints with a can of spray foam. By sealing everything up, you have now created your vapor barrier. Stud your walls out and batt them with an R11 unfaced insulation and proceed to drywall. I wouldn't put a layer of poly on the front face of the insulation or use a faced product at this point because you will now create a vapor lock/dewpoint in between the foam and the back side of your insulation which will eventually cause molding. If you're doing any electrical work, use old work electrical boxes that have no vapor gasket as well. Any moist air that does find its way into your wall cavities can seep through the electrical boxes and be eliminated by heat/ac or a dehumidifier once inside. Good luck, do it right and you'll avoid tearing out moldy walls in a few years.
 
You could also use tyvek tape and not have the mess you could get with the spray foam.

Tyvek tape works for tyvek but does not stick well on rigid foam and will fall off within a few months which will be right about the time you completely finish your basement and you can no longer do anything about it. Stay with the spray foam, it doesn't matter how ugly or messy it gets as long as it's sealed.

Also, make damn sure your rim joists around the perimiter are batted or thermaxed before you seal up the ceiling, this is where the majority of your heat loss and cold air come through. A rigid R7.5 foil faced thermax would be acceptable for a house your age but honestly i'd try to get an R10 in there to be safe. A poorly insulated rim will pretty much wipe out any good you do in the wall cavity.
 
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