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post #871 of 885 Unread 09-04-2014, 11:00 PM
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Originally Posted by Tnedator View Post
I posted about this in my build thread (Bacchus Palace), but will briefly mention here.

I was using open cell foam in my entire house (stud bays and roof deck). In the HT, Erskine wanted no more than 3" of foam, leaving 2.5" clear (2x6 wall) for them to put their R13 fiberglass batts. For this reason, to make sure I could a good air barrier and R-value at least as high as the rest of the house, I went with closed cell foam in the home theater.

I went over the thickness requirement no less than five times verbally with the foam guy and three times in writing/email, which he acknowledged. When it came time to spray, the owner of the company didn't supervise, and they sprayed 4.5-5.5 in about 60+% of the wall area (440 WSF) on the two exterior walls where they sprayed.

I found out the week before the Erskine Group was set to show up, and the foam guys told me they were going to trim it back. I talked to them the Saturday before (EG starting work on Tuesday), and they said, "don't worry about it, we'll take care of it." I show up mid-day Monday and it's still there. I call the foam guy and he explains that once this stuff sets up, it's almost impossible to remove without grinding it out, he suggested I firr out the walls 2" and he would pay for that cost. I explained that my aisles were already so tight, that even 2" would be impossible (I was trying to have a curved row of seats).

Anyway, long story, short. My contractors and I spent about 4 hours using every tool they had or could buy locally (hand saws, reciprocal saws, planers, etc.) to trim this stuff back, and while all of it would make a dent, it would have probably taken 10-12 hours of solid work to get it done. They do make some specialty tools for trimming back closed cell foam (we didn't have it, and at the time, my foam guy didn't - he does now, too late for me).

If the week earlier, I hadn't taken the foam guys word, and started my contractors on it, we probably could have trimmed it back either by ordering in some tools, or just taking several days to do it (except the places where gas lines and electric (gas lanterns on exterior garage wall) had been pushed to the front of the foam (this closed cell stuff is nasty to work with). In the end, I ran out of time, and told them to firr out the walls about 1.75" (2x4 ripped down the center), which gave us the amount of space we were originally supposed to have for fiberglass.

If you opt to go with a 2-3" of closed cell foam (better air/vapor barrier at that thinness than open cell foam -- it's actually a vapor barrier, which open cell isn't), then make sure, maybe even get in writing, that they know the maximum thickness, but more importantly, do it early enough that if it needs to be trimmed back, you have lots of time to force the foam guy to trim it back.

For me, what this has meant is I had to switch from curved seating to straight seating. I was right on the edge for aisle width with the curved seating as it was originally designed, and then I took away 2" going to 2x6 construction on the exterior wall and then nearly another 2" when I firred out for the foam mistake. While 3 3/4" doesn't sound like a lot, my aisle right where the columns were was so tight, making each side 2" narrower just crossed a threshold and just made it too tight.
Couple of questions...
If you were using open cell foam throughout your house, how did you end up with closed cell foam in the theater?
If you ended up with 4 - 4.5" of closed cell foam, either they have no idea what they are doing or they sprayed in two passes with time in between. Spraying 4.5" of closed cell generates so much internal heat that it could actually catch fire!

FYI Any wires, gas lines (flexible) or anything that is not absolutely rigid has to be fastened to "something" so that it does not move!!! Especially 2lb foam (closed cell) will push them out and you ain't going to do anything about it later. The 1/2lb (open cell) will need to be trimmed and any wires beyond the face of the studs will get damaged. An experienced sprayer can hold the loose wires in place while he sprays one side of the stud space, by the time he is coming back up the foam is set and will hold the wire in. But don't rely on this happening. Fasten everything!
Closed cell foam is a vapour barrier if it wraps around the back of the stud, completely. If you have exposed wood on the back side of the stud, you need a super 6 mil poly vapour barrier. Wood is considered permeable to moisture. Open cell foam is not a vapour barrier.
Closed cell foam is rigid and transmits sound very well. Open cell foam has more of a deadening effect.
Closed cell foam actually deteriorates over the first few years, as the cells pop, lowering the effective R-value. Open cell foam deteriorates to a much less degree, losing less R-value. After 5 years you would be questioning if the extra dollars were worth it. Don't get me wrong there are times when the closed is the better choice.
Unlike the spray cans of foam, these two-part foams are expanded and set in seconds.

Winterfell theatre build - working title
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post #872 of 885 Unread 09-05-2014, 05:30 AM
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Originally Posted by just jim View Post
Couple of questions...
If you were using open cell foam throughout your house, how did you end up with closed cell foam in the theater?
If you ended up with 4 - 4.5" of closed cell foam, either they have no idea what they are doing or they sprayed in two passes with time in between. Spraying 4.5" of closed cell generates so much internal heat that it could actually catch fire!

FYI Any wires, gas lines (flexible) or anything that is not absolutely rigid has to be fastened to "something" so that it does not move!!! Especially 2lb foam (closed cell) will push them out and you ain't going to do anything about it later. The 1/2lb (open cell) will need to be trimmed and any wires beyond the face of the studs will get damaged. An experienced sprayer can hold the loose wires in place while he sprays one side of the stud space, by the time he is coming back up the foam is set and will hold the wire in. But don't rely on this happening. Fasten everything!
Closed cell foam is a vapour barrier if it wraps around the back of the stud, completely. If you have exposed wood on the back side of the stud, you need a super 6 mil poly vapour barrier. Wood is considered permeable to moisture. Open cell foam is not a vapour barrier.
Closed cell foam is rigid and transmits sound very well. Open cell foam has more of a deadening effect.
Closed cell foam actually deteriorates over the first few years, as the cells pop, lowering the effective R-value. Open cell foam deteriorates to a much less degree, losing less R-value. After 5 years you would be questioning if the extra dollars were worth it. Don't get me wrong there are times when the closed is the better choice.
Unlike the spray cans of foam, these two-part foams are expanded and set in seconds.
Yes, it was done in at least two passes. I wasn't there for all of it, but I did stop by, before going out of town after they had done just a small part of the room, and I would guess they had done about 1.5"(on average) lift. They were supposed to make another pass and bring it to 3", 3.5" tops.

What happened on the second lift was it was very non-uniform. So, in an given stud bay, half of it might have been close to the 3 - 3.5" mark, but then there were large sections that were out close to the face of the 2x6. Again, since I wasn't there, I'm not sure exactly how they managed to screw that up. Bottom line, once it was set, and they didn't have any tools to remove it from within the stud bays (a pain, but much easier to simply trim back to stud faces), that left us with our problem and not much time to address it.

On choosing closed for the home theater it came down to a few things. Since I was only getting 3 - 3.5" of space to foam, I opted for closed cell, because it has a higher R-value (even aged, based on what I have read) than the open cell. The 3 - 3.5" of closed should roughly equal the 5.5" of open used else where. Now, while you could argue since I was also going to have R13 batts, I could have gone with open and the batts and been the same as the 5.5" of foam elsewhere -- which is true. However, since I already knew this "bonus room" location was going to be a challenge to cool, I wanted extra r-value.

Also, the other advantage I saw to closed cell was that if they got thin in any spots with the open, I might not even have a good air barrier, where closed cell is a vapor barrier at 2.5" or so, so it would definately be a good air barrier.

On the vapor barrier, I don't really need it, since I went with Zip system on my house, so there is a vapor barrier all around the house. That said, based on what I have read on building sciences foundation and other places, they do claim that studs act as a vapor barrier and that when used with closed cell foam, 6 mil polly isn't needed. It's been a while since I read that, so I couldn't point to exact articles, but I did read it in several places.
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post #873 of 885 Unread 09-08-2014, 06:40 AM
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Here's a quick novice "oops": I didn't check if my basement floor was level. I now have a screen that's either perfectly parallel to the ceiling, perfectly parallel to the floor, or somewhere in between.

All of which are noticable/irk me. Might be time to redo the drop ceiling.
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post #874 of 885 Unread 09-11-2014, 07:32 AM
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I had 4 large windows in my dedicated home theater. After much research I determined I could safely drywall over them. I read multiple posts where people suggested that I could pull the blinds down, stuff some insulation in the cavity and drywall the window. Sounded great, and looked fine from the outside. Problem is, the blinds that were already in the window were vinyl. After about 6 months of sun exposure, they have melted into a messy brown looking mess. Now, since I can't remove the windows from the outside, I need to cut into the drywall, rip out the blinds, and put something in its place. What a mess.... I dread getting drywall dust all over my carpet, screen wall, chairs, etc...

Last edited by Lickety; 09-19-2014 at 11:42 AM.
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post #875 of 885 Unread 09-11-2014, 08:25 AM
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Quote:
Originally Posted by Lickety View Post
I had 4 large windows in my dedicated home theater. After much research I determined I could safely drywall over them. I read multiple posts where people suggested that I could pull the blinds down, stuff some insulation in the cavity and drywall the window. Sounded great, and looked fine from the outside. Problem is, the blinds that were already in the window where vinyl. After about 6 months of sun exposure, they have melted into a messy brown looking mess. Now, since I can't remove the windows from the outside, I need to cut into the drywall, rip out the blinds, and put something in its place. What a mess.... I dread getting drywall dust all over my carpet, screen wall, chairs, etc...
That sucks!

Although I don't have a smart solution for avoiding cutting into the drywall, it seems like it should be possible to get in from the outside but that might be more trouble and damage than it's worth.

But as to the drywall dust etc, definitely create a air tight space around the windows, using large sheets of plastic and lots of painter's tape. It should look like a hot zone, or like the house in ET when the government shows up. Or like one of Dexter's killing rooms. That will definitely help, and it's relatively cheap.

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post #876 of 885 Unread 09-11-2014, 09:57 AM
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I have had nightmares about being stuck in the "ET" zone sanding drywall after removing the blinds...

And to my other lesson learned - Don't do drywall. Hire that out!!!!
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post #877 of 885 Unread 09-12-2014, 12:07 PM
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Buy good Fabric scissors, Don't use your fabric scissors to cut the Velcro.
Don't Forget to pay attention to the fact that your theater seats either recline forward or back, because that can totally mess up your riser plan...
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post #878 of 885 Unread 09-12-2014, 12:39 PM
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Don't Forget to pay attention to the fact that your theater seats either recline forward or back, because that can totally mess up your riser plan...
Explain this a bit more... I have read if I build my riser 6'8" total depth, I will be okay - regardless of the recline forward/back... that might just shift the chair towards the front or back of the riser.

Do I need to be concerned? I hope to build my riser next weekend.
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post #879 of 885 Unread 09-12-2014, 01:46 PM
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Explain this a bit more... I have read if I build my riser 6'8" total depth, I will be okay - regardless of the recline forward/back... that might just shift the chair towards the front or back of the riser.

Do I need to be concerned? I hope to build my riser next weekend.
Ok well my entrance is rear of the room and I have 13" columns in the back of the room to contain surround speakers. So I must be able to slide by the couches to enter the room. With a rear recline it would recline backwards and rest against the wall when occupied, but leave enough space to enter when upright. Now with forward recline it will hit the planned location of my bottom row, so I must split the rows. Although I have put the chair outlets center stage... So I'll have to have an offset split I guess :-(. Idk yet we'll see when I get there.
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post #880 of 885 Unread 09-18-2014, 07:52 AM
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Originally Posted by Lickety View Post
I had 4 large windows in my dedicated home theater. After much research I determined I could safely drywall over them. I read multiple posts where people suggested that I could pull the blinds down, stuff some insulation in the cavity and drywall the window. Sounded great, and looked fine from the outside. Problem is, the blinds that were already in the window where vinyl. After about 6 months of sun exposure, they have melted into a messy brown looking mess. Now, since I can't remove the windows from the outside, I need to cut into the drywall, rip out the blinds, and put something in its place. What a mess.... I dread getting drywall dust all over my carpet, screen wall, chairs, etc...
similar problem...my windows are vinyl and the trapped heat has melted the frames. they are wavy, trim pieces are falling off, etc. will have to totally replace them.

fortunately i didn't drywall everything in, just used foam "plugs" covered in black felt.

but it's not just blinds that can be damaged.

- Chris
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post #881 of 885 Unread 09-20-2014, 09:04 AM
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similar problem...my windows are vinyl and the trapped heat has melted the frames. they are wavy, trim pieces are falling off, etc. will have to totally replace them.

fortunately i didn't drywall everything in, just used foam "plugs" covered in black felt.

but it's not just blinds that can be damaged.
We are building, so I didn't have existing windows. However, the architect originally called for three windows in the area. I had originally considered putting blinds or curtains in real windows and then sheetrocking over them (simply to keep the look good for the outside of the house). By builder talked me out of it, due to concerns about if the window leaked or something like that and having no way to access and fix it. I took his advice and instead did some brick designs and window trim in those areas (just so there wouldn't be so much brick with nothing on it).

Based on what you guys are describing, I'm real glad they talked me into going this route or I would be in the same boat as you guys.
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post #882 of 885 Unread 09-20-2014, 02:09 PM
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That sounds like a good idea. Pictures?

Downloadable FREE demo discs:
http://www.avsforum.com/t/1475769/de...ently-authored 

Did you really need to quote that entire post in your reply?
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post #883 of 885 Unread 09-20-2014, 10:36 PM
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That sounds like a good idea. Pictures?
Was this question aimed at me or someone else? If me, then no pictures, because we haven't bricked that part of the house. Also, we are doing precast trim around our windows. So, for those three spots, we will do the pre-cast trim just like the other windows, but with a herringbone pattern of brick inside the precast trim.

Don't get me wrong, nobody will mistake those for windows. Instead, it was supposed to just break up which would otherwise be big areas of brick and areas that looked like there should be windows.
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post #884 of 885 Unread 09-21-2014, 01:27 PM
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I'm certainly not interested in pictures of rotting frames and blinds.
But pictures of alternative approaches to "fake" windows would probably be interesting.
Anyone use glass block and then cover that on the inside?

Downloadable FREE demo discs:
http://www.avsforum.com/t/1475769/de...ently-authored 

Did you really need to quote that entire post in your reply?
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post #885 of 885 Unread 10-01-2014, 10:57 AM
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Very helpful, thank you to everyone who contributed to this thread!
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