Cement board/Apt. Noise

[Steve Leverich]

Thanks Matt, I'd be really depressed if I didn't - unless you've ALSO spent the last 25 years (off and on) digging into it and helping several thousand musicians worldwide in the past 4 years to build studios they'd never have had - those last 4 years were also a peak in my own learning curve, including friendships with several VERY smart people who were willing to share.

In spite of spending an average of about 20 hours a week helping others, I feel I got the better part of the deal every time someone finished doing what we recommended and were amazed that they couldn't tell a drummer was thrashing his kit on the other side of a wall, till they opened the door(s) and had to plug their ears

I've actually had a few people build spaces, then THANK me for badgering them to tear down entire walls and start over - the difference in isolation can be that amazing... Steve

[Chris Padilla]

Good stuff, Steve. Thanks for the link. I WAS planning a master bath addition to my master bedroom (2nd story) and was seriously considering some stuff on the soundproof.org site. Unfortunately, bids came in about 50% higher that I expected so no new master bath!

I have your link added to my "sound" bookmarks for that one day in the future when I build my own home!

[Matt Mutus]

Steve, since we're on the topic... maybe I can ask your advice.

The reason for my friends garage is my band need a new spot to practice. The inside wall touches the house, the outside wall faces the neighbor. The back wall has a regular door and the front wall is a retractable garage door. It has a peak ceiling sloping up/down from front to back. There are no windows.

The outside wall is concrete up to about 7 feet, then above that raw framing up to the peak. The ceiling is also just bare frame. The house wall is all concrete up to the peak.

What we've done is put insulation into all framed areas, then apply silicone to studs, followed by sheetrock then MLV. While the original plan was to add another layer of sheetrock over the MLV, we're now thinking of seeing how it works before going any further.

for the concrete wall on the house side, we are going to frame a wall 3-4 inches out and then hang sheetrock/MLV/sheetrock on that. We were also planning to do the same to the other concrete walls which don't touch the house, however we now want to test before going any further. There is not a lot of floor space so if we will avoid framing out new walls if we can.

My biggest concern is the doors, especially the garage door. The system will only be as good as the weakest link and this seems to be it.

My friend has made some hanging pieces that will block the doors when we play, I forget exacty, but the are mainly insulation and MLV from what I remember. He got this idea from a guy who was advising him.

1) for the bare framed areas, do you think another layer of sheetrock on top of the MLV will have enough impact to make it worth the trouble? or will it be a case of diminishing return give that it's a huge PITA to do it.

2) Short of buying a new garage door, do you have any tips to soundproof the doors, espcially the garage door. What ever is there has to be removable.

thanks very much - Matt

[Steve Leverich]

Matt, this is a common problem with few workable solutions - here is one of the best, check a few pages either side of this one

http://www.johnlsayers.com/phpBB2/vi...=asc&start=435

The basic concepts of sound isolation are

1. Hermetic seal (if it won't float, it won't hold sound in or out)
2. Mass - the more the better but ALWAYS in TWO places - no more, no less.
2-a. IF this isn't possible (like the garage door) then try to build your mass-air-mass construct as close as possible to the door, use an extra layer of mass (like 3 sheets instead of two) - the idea here is to minimise the "3-leaf effect" by beefing up the two leaves you have control over, thereby lessening the "3-leaf problem".

Avoid flanking - if your inner walls/ceiling cannot be separately framed, then using resilient mounts for inner wallboard (ALL layers) is a (very) second best. Best is a floated room-in-room, which becomes very math-intensive. Not recommended for less than high-budget with NASTY neighbors.

As to being able to breath in your hermetic room - check out the "stickies" at the top of the Construction forum, under "ventilation, poor man's air conditioning, etc." - the secret is long, large cross-section ducts with at least two 90 degree corners and fiberglass duct liner (such as JohnsManville "superduct")

I've probably forgotten to mention a few items - for a few evening's reading, here's the best place to start

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=2125

I've done several representative sketches on that site for different scenarios, but you can imagine that in 4 years they've gotten kinda buried - if, after reading thru the "reference section", you still have questions (I'm sure you will) post back here and I'll see what I can do.

It'll help if you can draw a sketch of some kind showing your walls, in enough detail to see where frames, panels,layers, holes, and insulation are located.

It'd also help if I knew whether you need to be able to actually OPEN the garage door or just "return the space to normal" after you don't need it for practice... Steve

[Matt Mutus]

Steve thanks for the detailed response. I'll read through the material and see if I have any followup questions.

as for the garage door, it will definitely have to be opened to get our gear in and out between gigs/practice.

thanks again, Matt

[Steve Leverich]

" as for the garage door, it will definitely have to be opened to get our gear in and out"



I had ta ASK... you SURE there isn't another door for that? Durn... Steve

[Matt Mutus]

well there is a back door but it's pretty thin. 28 inches I believe. Be a real pain to carry stuff around and through the skinny door. I'm not sure the guy who owns the house wants to permanently or even semi-permanently block off the garage door.

But it's his wife and kids on the other side of the wall, and his neighbors - so if he's happy I'm happy