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Discussion Starter · #1 ·
Since I don't think anyone sees my built thread I figured I would ask in a new thread. . .


Insulation Questions:


I'm getting ready to insulate the theatre portion. I'm doing blown in closed cell for rest of basement.


I'm using R19 in the ceiling unfazed correct?


For the walls I'm using unfaced R13 not R11 Correct?


The one wall is a outside wall. 12 inch concrete pour totally underground. Am I using unfaced on this wall also? or should the paper be attached to the insulation for this wall only?


Thanks guys,

Jim
 

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I'll take a stab at this, but it's been a while since I went down this road.


R19 in the ceiling, faced or unfaced doesn't matter, just get what's cheapest. I will say you might try finding a local drywall or insulation supplier as that ended up being much cheaper than my big box stores.


R13 in the walls is correct, assuming you have 2x4 construction. If it's 2x6 construction, then R19 might be the way to go, but I'd have to doubled check that.


Now the exterior wall is a bit more complicated. Do you have an existing vapor barrier on that exterior wall? Correct application of vapor barriers is a hotly contested topic, but assuming you have a bare concrete wall right now, my first step would be to call your local building inspector and find out what they recommend in your area. In my part of the country they actually don't require a vapor barrier, so I went with unfaced insulation. However, as you move north, a vapor barrier is an absolute necessity. It's very important to get it right. If you have the extra coin, a closed cell spray foam is one of the easiest ways to make sure you get it right regardless of where you're at.
 

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Discussion Starter · #3 ·
Sorry I didn't realized u responded here too!


So forcthe whole basement minus the theatre I'm going closed cell. 2 inches.


For the theatre no foam so I don't mess up my decouple job.


So I can used face in my ceiling if I wanted? I didn't realize that.


For my exterior wall. The outside is tarred. It's pretty much want they do in my area.


I guess I'll have to check with a code officer for my town to get more info. I could swear the guy who designed our house said I didn't need a vapor barrier in my area since it's totally below grade.


So u r unfaced? Is that cause u have a vapor barrier outside already?


I wish I could so foam but I only got 1 inch to the wall so 1 inch won't get me a vapor barrier anyway.


What do you think?
 

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What part of the country are you in? It's obviously too late now, but in your situation I would probably have given up the extra inch in the theater to have the no hassle no worries foam vapor barrier. I've read too many horror stories about incorrectly applied vapor barriers.


From what I remember, I believe Ted's recommendation about faced or unfaced is basically go with the cheapest when vapor barrier is not an issue. There is really no difference from a sound absorption standpoint. Any sound that would "see" the facing will be high frequency, and the drywall will reflect that well before it gets to the paper facing.


When I built my house two years ago, there was little-to-no information regarding exterior waterproofing and its relationship to interior vapor barrier application. Our basement has a sprayed-on coating (like tar but with a rubberizing additive) as well as a heavy plastic drainage mat followed by a drainage board. Whether or not you need a vapor barrier below grade will depend on your location. I believe the further south you go in the states the greater chance it will not be required. If you live up north or in Canada, you absolutely need one.


I used unfaced spaced about an inch off the walls because of the soil temperature vs ambient temps in our area (mid-Alabama). If I remember correctly, subsurface soil temps in this area can approach 70 degrees. So it's hard to predict which direction the vapor drive will be. So far this has certainly been the case as our basement maintains around 50% RH and the temps stay below 70 degrees year round. So it's possible for the soil temps to be higher than the basement air temps in the fall/winter, but during the summer the reverse would be true. Up north, the basement walls will always be colder than the comparatively warm humid basement air, which can result in condensation.


At any rate, I'm going from memory as it's been two years since I looked into this, so I think you would be best served by calling your building inspector and checking on the local requirements.
 

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Discussion Starter · #5 ·
So I can use faced if I wanted to. I thought u weren't suppose to used faced for the theatre walls and ceiling? So if I can used faced and not ruin anything sound wise then I'm fine and that will be my vapor barrier. Correct?
 

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If you are still talking about the exterior wall, It's not that simple. I don't think regular faced batt insulation is recommended for use as a below grade vapor barrier anymore. Most places where it's required either use foam (either sprayed or panels) or the plastic diaper approach. There may be other options, but that's what comes to mind.
 

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Discussion Starter · #7 ·
Oh ok gotcha. But from a sound proofing stand faced or unfaced doesn't matter. I always thought it had to be unfaced only cause the paper messes it up. Thanks sorry and that will be the last question. I promice!
 

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Discussion Starter · #9 ·
You know I tried some searched but got nothing useful. I'll check this out in a bit and type back what the code officer told me vs the blown in closed cell guy I'm using vs certainteed told me. I appreciate all the help and links! I'll be back!
 

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Discussion Starter · #11 ·
Ok so I didn't get any solid info from the code inforcer for my town. He said in pa that they separated themselves from the national builders code a while back and kinda defer to manufacturer recommendations. That didn't make sense cause you need a code to dictate what to even use. Not how to install what you don't even know what to install. He pretty much said since I was all below grade and if the wall hasn't had a problem I the past then a vapor barrier isn't a huge deal. He said to dry lock it and if I wanted 6 mil plastic between the concrete pour and insulation. I said the wall is already up so plastic isn't going to happen and he didn't mind. I said should I use faced or unfaced insulation. He said I could just used faced and call it a day pretty much. So I hung up and called my spray foam guy cause that conversation was pretty much anything I wanted to do I could do. No help.


My spray foam guy game me some ideas and said what he would do. He said my basement is dry. He knows me forcthe past 8 years and has been in my home many times. He said we know we don't have water issues so that won't be an issue. He recommends since we can't get 2 inches behind the wall to just use unfaced and call it a day. He said because the wall is totally buried. He said if the wall wasn't buried he would go with faced. He did say that doing the rim since it's above grade that we should do that so if any moisture gets through there since above grade we won't have a problem then with the foam in place vs bats. He said if the wall was above grade he would use faced. If part the wall was above ground and part below he would face above. Unfaced below. He says this cause he likes the idea of the air being ablecto pass back and forth to even out. He said with the face insulation u can't get that balance then. He is going to find out from the foam manufacturer if we skim the wall with a 1/2 inch if that would help and then go unfaced bit he is thinking it would be like putting 6 mil plastic up against the wall and he said that is just stupid and a big mistake.


So certainteed. A pa company. So familiar with building code here. They said exactly what the foam guy said.


So I'm going unfaced to hopefully allow a balancing effect if any moisture gets back there. Deff going to do the rim joist in the theatre area too along with rest of basement rim joist like I was already. He will get back to me about the 1/2 of foam if it will help.


He said in closing. If I called him first we wouldn't be having this conversation cause I would have the 2 extra inches I need for foam. I said ya ya ya. By! Lol


So here in pa he pretty much said if u got a dry basement which he feels I always will cause the house made it through 2 major 100 year floods with zero water and hydrostatic pressure up against wall so a vapor barrier isn't a huge issue being underground.




Quote:
Originally Posted by J_P_A  /t/1522359/insulation-questions#post_24477820


If you are still talking about the exterior wall, It's not that simple. I don't think regular faced batt insulation is recommended for use as a below grade vapor barrier anymore. Most places where it's required either use foam (either sprayed or panels) or the plastic diaper approach. There may be other options, but that's what comes to mind.
Quote:
Originally Posted by J_P_A  /t/1522359/insulation-questions#post_24478142


From the 'ol search function. Here's Ted's opinions on faced vs. unfaced.

You don't need faced

But he likes to use it cause it makes installing it easier.
Quote:
Originally Posted by J_P_A  /t/1522359/insulation-questions#post_24478799


I'd be interested to know what they say. When I was researching the vapor barrier issue it seemed to be a topic with lots of opinions, but it was hard to find solid information that pertained to my specific situation.
 

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Wow. I had to leave this one alone for a day because I'm baffled by this. I suppose it makes me really appreciate our building inspectors as they are quite helpful.


I'm also a little surprised by the response from certanteed. There are two different issues that I think are being confused. Water penetration from outside due to hydrostatic pressure is different than water condensing on the inside due to warm higher humidity air coming in contact with the cold basement walls. The tar waterproofing on the outside is to deal with the hydrostatic pressure issue. The insulation and potential vapor barrier deal with the other. Maybe the humidity stays low enough there that it's not an issue.


At any rate, I'm not much help in this case. Sorry.
 

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Discussion Starter · #13 ·
Right that's what the guy doing my foam kinda was saying. 2 diff things to deal with. He knows we r safe outside and aren't worried about pressure or cracks to cause water penetration. He also knows the humidity stays very constant since I'm underground and knows this will change when the space is conditioned but feels confident with unfaced for the wall that in totally underground and to spray the rim with 2 inches since above ground. This is exactly what certainteed said since they were going on the assumption that there is no hydrostatic pressure or crack issues.


And yes the town code officer was of no help but that doesn't even bother me cause I would trust the people I know over him anyway.


So pretty much I'm going on faith that that wall will always be as it is now and another 100 year storm won't change anything and the humidity doesn't change much from now after the space is conditioned.
 
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