×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Type BA Acoustic Metal Deck

Type BA Acoustic Metal Deck

Type BA Acoustic Metal Deck

(OP)
I'm doing a small penthouse addition on an existing building. It is basically a steel framed box. While this is not really a structural question does anyone have experience with sound transmission of using only metal roof deck + insulation in a space like this. The architect is asking if sound such as rain will be evident through the roof. It would not be easy to get concrete up to the space and they are also trying to keep it as thin as possible. What about type BA acoustic deck? Never used it and not really sure if this is the intended application.

RE: Type BA Acoustic Metal Deck

I think the acoustic deck deals with sound generated within the building and knocks down echoes and reverberations from within. I don't think it does much with sound generated from outside (above) the building such as rain pounding on the roof. (or hail).

RE: Type BA Acoustic Metal Deck

We've used BA before without negative feedback, however I post this because we did have one job with an issue... the acoustic deck was requested by the architect for an auditorium, and vetted by their aucoustics consultant. Less than a year after construction we received a call asking if the roof structure had enough "reserve" capacity for them to strip off the roofing and insulation and place concrete or lightweight fill instead...

Apparently, the rigid insulation on the deck with an applied membrane acted as somewhat of a snare drum, to the point that one especially significant downpour "drowned out" their guest speaker at a commencement...with a microphone...and postponed the event.

To be fair, I have no idea if the acoustics of the space were such that using standard type B or any other decking would have mattered...

fyi

RE: Type BA Acoustic Metal Deck

The Steel Deck Institute Manual may help:

http://www.sdi.org/whites/moc2.pdf

I also have a steel deck question open at the same time, and I found it interesting you have one as well. I'm reading through the manual now.

p. 9 of 48 is the first mention of acoustic deck.

RE: Type BA Acoustic Metal Deck

(OP)
JAE - I think you're right, the more I looked into it it seems the intent is for sound reverberating off the deck from inside.

MBullism - thanks, the 'snare drum' effect is what I am worried about.

I found that Georgia Pacific has some info (STC Ratings) when using their 'DensDeck Roof Boards' on top of roof deck. In their tables they compare to metal deck with rigid insulation alone and it doesn't look great. It looks like the Dens Deck is basically just adding mass in terms of acoustic improvement. At some point I guess it makes sense to just get concrete up there instead. Will update this if I get any better info, I'm going to bug an acoustician.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources