[nathan_h]

As described in this thread here, I am converting my detached garage into a home theater and media room space.


Right now, as you can see from the photo, the walls are mostly drywalled, and the ceiling is not. I will be pulling off the old drywall, because it is in sad shape and because I want to re-wire the space.... and add an internal false wall.

I'll take this opportunity to insulate well in the walls, and in the ceiling.


But what kind of insulation to use? I live in California, where freezing temperatures are uncommon (usually) and it does get hot in summer, but climate control is probably going to be fine with any insulation I use, I think. So two factors matter:


1. price. I'm already busting my budget, so something on the lower end of the price scale is good.


2. sound. Although I'll have treatments in the room, and I don't care about a little sound spill to the outside, and I will be using Green Glue under the one layer of drywall where it is fastened to the studs, is there some insulation that is better than other insulation, both in terms of the sound in the room, and leakage outside?


(For example, should I be mail ordering OC 703? Is there something I can pick up at Home Depot? etc.)

 

[ifeliciano]



Quote:
Originally Posted by nathan_h /forum/post/0


But what kind of insulation to use? I live in California, where freezing temperatures are uncommon (usually) and it does get hot in summer, but climate control is probably going to be fine with any insulation I use, I think. So two factors matter:

Usually the same stuff that is in the outside wall cavities of the rest of the house.

Fiberglass R-13 or so. Check with HD or Lowes the carry the insulation you need for your walls. OC 703 is a rigid fiberglass board used for ducting system but in the HT will serve as an acoustic treatment you shoud be able to find at a insulation specialty place not HD.

 

[Smarty-pants]

Blown-in insulation is the best. You'd have to pay someone to come out and blow it in the walls and above the ceiling. It's probably going to cost more than the DIY roll-in variety, but if you factor in the cost of paying yourself for labor then it would even out. The key to insulating well is to get every tiny crack, nook, and cranny filled with insulation and nothing does it better than blown-in. Also, as far as the cost, any extra cost is going to pay for itself over time via energy savings.

 

[nathan_h]

Thanks for the feedback. Guess I'll price out the two options, taking into account the factors described.


Assuming I one day realize I need to run cable or electricity in a place that I didn't, before, which kind of insulation is more difficult to deal with?

 

[Smarty-pants]

Blown-in insulation is way more difficult to deal with if you have to go tearing into the walls and ceiling... very messy. Again, being as how you're in a pretty mild climate all year round, you'll probably be ok with rolled in insulation. If you do, just make sure your very liberal with it. If there's a crack or a nook in the walls where you can stuff some in there then do it. People don't realize how much money is lost when a house is not as well insulated as it could be.

 

[nathan_h]

Phew yeah this is a mild climate compared with Ohio! Around here, it's front page news when the weather at night dips below freezing

Thanks for the advice. I definitely need something that is "user friendly" so that when I decide to retrofit something, I can do so with a minimum of fuss and skill.

 

[jandawil]

If you are using GG you should leave the existing layer of DW up. I did that in my garage HT conversion and drilled 2 1/5" holes every 16" on center above and below the fireblock with a hole cutter on my drill. I went down to Lowes and bought 20 bags of the blow in insulation and they let you borrow the blower for free. I took me only about 4 hours to do both of my walls and the entire attic space, but it is a 2 man job for sure. There are some photos and more explanation on my HT build site. It was pretty easy and only set me back $200 for everything. I than plugged the holes up with the pieces I cut out and used GG and the second layer of DW to cover up the ugly mess. Came out great.

 

[nathan_h]

Good to know about the free blower. However, I think for ease of future changes, I may go with rolls of insulation.


I REALLY considered just drywalling a second layer over the existing drywall -- but:


1> It's in pretty bad shape (holes, stains, lots of nails).

2> The electrical looks like it was put together by a committee -- with some outlet boxes stuck at random places flush with the drywall, or out in the room, or in the ceiling.

3> I'm worried about the condition of the inside of the exterior wall behind the existing drywall -- and taking out the old drywall would let me check it all out, clean it, and seal it with some primer.

But maybe I'm being overly cautious! Perhaps pulling off just the worst one or two sections of drywall, and seeing how it looks underneath, would tell me whether to proceed by removing it all, or fixing what's there.


Note that I only got ONE BOX of green glue, so I need to concentrate on using it in the most impactful manner. From what I can see, this means using it where the studs meet the drywall, which would take less glue than using it on a second later of dryall.



But I could be completely missing the boat, and would appreciate more insight / experience to help guide me!

 

[Smarty-pants]

I would tear out the old DW. You don't know what's behind there or even if it's insulated or not. If it's an older home, the insulation (if there) is probably outdated. Most houses do not have insulation behind the DW of an outside wall in a garage. You can re-run wires exactly where you want them, add outlets and switches exactly where you want them, add blocking in places where you may need it for hanging anything on the walls, make sure there are no infestation problems. Even a couple little bugs or spiders can become a huge problem later when you seal the room up and it gets temperaturized well, allowing them to flourish.

 

[jandawil]

As an FYI...GG on the studs does very little compared to double layers of DW. You may want to email Ted White from Audio Alloy (makers of GG) to check...but if you read any of the threads on GG this is what you will find. I had one common wall between my house and the garage as you may as well so focus on the common walls. I built out a separate wall so I have 2 walls (one with GG and double DW) seperating my house from the the HT. I installed 2 doors that will form an airlock between the theater and the house. It works quite well. I can crank a movie pretty good with minimal noise in the house. Even with that some of the LFE does get into the house. It is very expensive to get all of the bass under contrail. I used 3 cases because I treated all walls. I did the 50% coverage which was one tube per sheet.

 

[nathan_h]

Thanks for the tip. I'll research this some more.


Luckily the garage is FULLY detached and, in fact, 25ft away from the house. Trouble is, it sits right next to two different neighbors' yards, and is actually closer to one of their houses than it is to mine.


I want to have NO CONCERNS about volume

 

[trekguy]

You don't say where you are in the Bay Area, cooler areas vs warmer. I'm just over the Oakland Hills in CC and I used to live in Oakland. So for both those micro-climates may I suggest some things.


When it gets cold you are going to want heat. When it gets hot if you will really want good insulation. Go R-36 in the overhead. It's true that gain is not linear so R-13 will get you most of it. But you won't want to be uncomfortable. If you want to keep the beamed look their are rigid insulation materials you can apply between the joists.


Blown in vs firberglass. Your square footage is small, so your savings will be small, and there is the joy of patching 2 holes per stud bay.


Wiring- the stuff you have was dangerously done by the 3 Stooges Electric Co. You will want to pull it all out.


Pull off the DW. Makes the wiring easy and lets you check for water, fungus, etc.


Consider using flexible Z strips to mount the second layer of drywall on the walls. It works well and it cheap.


There are kits of rigid insulation for garage doors like yours. If sound transmission is critical don't forget weather striping.


Replace the window with a double pane job.

 

[nathan_h]

Thanks for the suggestions. I'm in the South Bay, so both cold and heat (especially heat) can be a concern, depending on the time of year. I plan to get a "split" HVAC system that can both cool and heat, as needed.


Yes, I agree that the wiring is whacky. "3 Stooges Electric Company." No doubt! Makes me worried about what might be hidden in the main house!


I'm going to have one box of Green Glue, so I can use that for the second layer of drywall, I think. I hadn't originally budgeted for a second later of drywall, but now that the Green Glue is a reality, I'll want to do that, it sounds like.


R36 huh? Okay, sounds plausible. This weekend may be my first look behind the drywall, so I'll take a few photos and share the results.

 

[nathan_h]

Has a renovations guys take a look at the main house today, and as an added bonus, he review the stuff in the garage. He agreed about yanking out the electrical and starting over, but he suggested that the drywall, after a few repairs, was actually not too bad -- especially if I'm thinking of a second batch of drywall on top of it -- and there is already blown in insulation behind it! Still a little worried about what might be behind it, but I'm tempted to follow his advice.


Of course, doing the electrical without pulling off the drywall is more of a challenge, but maybe it's worth it.

 

[Smarty-pants]

Blown-in already existing?... good deal. Since that's the case w/the DW. Don't worry too much about fishing new wires through as you can just knock holes or channels though the old drywall to do it. It's going to get covered up with new DW anyway. Being a garage, it'll be easy to guesstimate any existing hazards behind the DW too. Punch a little hole here and there to see if there any mold or infestations. Mybe close it up and set off like 3 bug-bombs it there or something like that. BTW, not to make you paranoid or anything, but bats love to nest in blown-in insulation.

 

[nathan_h]

If the bats don't harm anything, that's cool. But I think I will plug and caulk any openings, so I 'm not sure they'd want to continue staying there. (The cats might find them interesting...)


There are a couple of holes so we'll poke around a bit more and make sure there is nothing too ugly going on inside.


I didn't think at all about cutting channels into it for new wiring, and then patching over it. That's EXCELLENT. I guess the insulation will be a bit of a hassle, but I'm sure it can work. Thanks!

 

[trekguy]

While you are looking do an exploratory near the top of the wall. Blown-in insulation may have settled with time or been poorly installed. You don't want any empty areas at the top of the studbays.


I don't know about bats, but the infamous Norway and roof rats like all types of insulation for nesting and there are no built up areas here that are free of them. Check for droppings near any openings you may find. From personal experience I call tell you that one of our furry friends trapped in a wall can produce a very long lasting odor and a major mess when you try to guess which part of the wall to open. If you find rodent sign you can set traps for several days- the idea being to get them when they are out and around. Don't use poison because they have time to get back in the walls.

Lots of stuff you really didn't want to think about, eh?

Good luck and keep us posted.

 

[nathan_h]

Hmmm. Yes, the cats could find such new "friends" interesting, too, I think.


I didn't think to check the top of the stud bays, but that makes a lot of sense. Thanks.

 

[nathan_h]



Quote:
Originally Posted by trekguy /forum/post/9513082


You don't say where you are in the Bay Area, cooler areas vs warmer. I'm just over the Oakland Hills in CC and I used to live in Oakland. So for both those micro-climates may I suggest some things.


When it gets cold you are going to want heat. When it gets hot if you will really want good insulation. Go R-36 in the overhead. It's true that gain is not linear so R-13 will get you most of it. But you won't want to be uncomfortable. If you want to keep the beamed look their are rigid insulation materials you can apply between the joists.


Blown in vs firberglass. Your square footage is small, so your savings will be small, and there is the joy of patching 2 holes per stud bay.


Wiring- the stuff you have was dangerously done by the 3 Stooges Electric Co. You will want to pull it all out.


Pull off the DW. Makes the wiring easy and lets you check for water, fungus, etc.


Consider using flexible Z strips to mount the second layer of drywall on the walls. It works well and it cheap.


There are kits of rigid insulation for garage doors like yours. If sound transmission is critical don't forget weather striping.


Replace the window with a double pane job.

As you can see from my main thread http://www.avsforum.com/avs-vb/showt...5#post11293005 the good news is that there was minimal damage behind the old drywall. I was able to get all the old electrical OUT, and seal some cracks, and repair some structural issues, etc.


I'm curious, what are these "z strips"? I did some searching and couldn't quite figure it out.