Rod's book - ceiling construction question

Posted: Sun Mar 16, 2008 10:51 pm

Hello from a new member!

I have Rod's book and am planning a new home to be built this summer with a dedicated studio room on the main floor. The book is great - very informative and full of helpful details that give a novice like me very clear direction, except for one thing...I may be missing something, but I have read through the section of the book on wall and ceiling construction several times and I can't find a description of the proper way to construct a ceiling in a room that doesn't have a floor above it. The diagrams all seem to be examples of basement studios, and have floor joists and flooring on top the studio ceiling.

I know next to nothing about construction - am I misunderstanding what I'm reading? My builder has looked over the same chapter also and wasn't sure what to do for a ceiling that has roof trusses and an attic space with 18" of blown insulation above. I have tried to read every post that seemed to have to do with ceiling construction on this site, and I'm still confused. One guy wrote that he had built a double ceiling on his studio, but was informed he had created a three leaf system because he failed to take the roof into account. I very much want to do this right from the beginning. I have retained Ethan Winer for sound treatment advice, and will be purchasing his products for treating the room, once completed. He has been very helpful, but construction is not his area.

I don't have drawing software, but I'll describe the situation and plan as best I can. The room will be a single space for tracking and mixing, mostly just me on guitars (electric and acoustic), bass and vocals. I'd like to be able to record drums in the room, too, but don't expect to be doing this often. The house will be on a dead-end street with neighbors within 100ft. in one direction and a busy highway 300yds in the opposite direction. My wife and I will be the only occupants. I work a day job, so no all-night sessions. The bedrooms will be at the opposite end of the house, as will the mechanical room and laundry. I am more concerned with keeping out the noise of the neighbor's lawnmowers, barking dogs, highway noise, helicopters (we are on the flight path of the air ambulance), garbage truck, snowplow (Minnesota resident), than with disturbing the neighbors with extreme volume. The house will have in-floor geothermal heat.

The room will be 14ft. by 19ft. with an 8ft.ceiling on one end of the 19ft. length, rising to 11ft. at the other end. It will sit on its own concrete slab that is disconnected from the foundation of the house and garage as described in Rod's book. The 3 interior walls will be double 2x4 walls with 1" spacing between and 2 layers of 5/8" drywall on the inside of the inner wall and the outside of the outer wall, insulated, Green Glued and caulked as in the book. The exterior wall, one of the 14ft. ones, will be, outside to inside:
1. Steel siding
2. Tyvek Housewrap
3. Owens-Corning Blue Rigid
4. 2 layers 3/4 OSB, overlapping seams, with all seams caulked
5. 2x6 studs with fiberglass insulation between
6. 1" air gap
8. 2x4 studs with Owens-Corning pink between studs, paper side facing in
9. 2 layers 5/8" drywall with overlapping seams, green glue between layers, all seams caulked with acoustic caulk

The floor will be stained concrete. The door will be one of the Overly models described in the book. Framing and gaskets as described.

On the other side of the three interior walls:
1. garage
2. hallway from garage to interior of house
3. "sun room"/office.

On the other side of the ceiling is an attic with 18" of blown insulation and the roof.

A through-the-wall A/C unit in a small room in the walk-out basement below the sun room will provide cool air - vented up into the studio room as per diagram 7.5 in Rod's book.

My builder is a personal friend and will be doing the framing and drywalling of the room himself. When he saw the level of care that would be required in getting the details right, he told me he wouldn't let the drywall guys do it. He is willing to do whatever it takes to get the job done right. I will probably do the caulking/backer rod work myself for each layer of drywall after it is hung.

What's the best approach for the ceiling in order to get the level of isolation the rest of the room will achieve? Can you direct me to a section of the book that answers my question? Sorry if I've missed it. Thanks for an excellent site!

Doug

Posted: Mon Mar 17, 2008 4:14 am

Welcome to Rod's site on Recording.org!

Congratulations on your build and doing it right (planning before building). I'll leave the ceiling question to Rod to answer.

As I read your post I was curious about the performance of your outside wall. The closest I could find in IR 761 was on pdf page 352. That design is:

Element Description:
1 single layer of 16 mm type X gypsum board
2 single layer of 16 mm type X gypsum board
3 90 mm wood studs at 610 mm on centre
4 90 mm of glass fibre insulation in cavity
5 25 mm gap filled with air
6 90 mm wood studs at 610 mm on centre
7 90 mm of glass fibre insulation in cavity
8 single layer of 16 mm type X gypsum board
9 single layer of 16 mm type X gypsum board

The performance of that design has a TL of 26.7 dB@50Hz, which is excellent. With the difference that you have 2x6 studs, I seriously question the need for Green Glue in your application. It is an excellent product, but possibly not needed with the high standard that the wall design is. It feels strange writing to someone to do LESS than what they planning for sound isolation.

Experts will hopefully comment on my thought.

Good luck and enjoy your new home!

Posted: Mon Mar 17, 2008 8:08 am

Doug,

why is it that everyone makes things so much more difficult than they have to be?

OK - first - read the thread (it's a stickie) called "Read this first before you post" - and follow what it says........ that will get things started here on the right foot.

Next - not only did I put pretty pictures in the book - I also put things into word..........

What did I say about triple leaf systems and living with the cards they dealt you? Re-read chapter 10......... and think about things from your perspective.

My goal (job) with this book was not to details each and every asituation you could possibly come across........ it was to give you enough information that you could then take that and apply it to your situation.

It doesn't matter whether the details are of a floor assembly a ceiling assembly above........ substitute the truss for a ceiling joist - think on it a bit - and then get back to me..........

Sincerely,

Rod

Posted: Mon Mar 17, 2008 10:23 pm

Rod,

I'm sorry if my post made it seem as if I was complaining about your book. I most certainly did not intend that. Yours is far and away the best of the three books I have purchased on building a home studio. My lack of understanding is my fault, not yours.javascript:emoticon('

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Embarassed

I did read the sticky before I posted and thought I had included the required information in my post, even though it was probably poorly organized. I did do several site searches on ceiling construction over a period of several days. I am trying not to waste your time here and I appreciate that you are willing to spend your valuable time helping people like me.

I have no carpentry experience or skills and I'm doing my best to understand unfamiliar concepts well enough that I can tell my builder what needs to be done. I will re-read Ch. 10. I understand that two leaf systems are good, three and four leaf systems are bad.

Doug

Posted: Tue Mar 18, 2008 7:32 am

Nope - him don't get it.............

It isn't a good bad thing - it's most desirable to less desirable.......

Let's see - we build air locks - which are automatically really 4 leaf systems - as are hallways............

We can't avoid doing it - so we design according to our needs - and live with the end result...........

Same thing with small iso-booths.

My point is - you have to do the best you can with the cards you are dealt............

Sincerely,

Rod

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