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Re: LONG FLOOR JOIST SPAN

[Subject Prev][Subject Next][Thread Prev][Thread Next] A game room, eh.  A big, open room that people might dance in, or something active like that?  Even more reason to be VERY CONSERVATIVE about floor stiffness.  I think steel beams are a good idea; make them as deep as you possibly can, for stiffness.  The lack of dead weight, like a concrete topping, makes a long-span floor susceptible to feeling bouncy. 

Many modern airport terminals that I've been in also feel bouncy, in spite of their steel framing and concrete topping, when the thundering herd comes off a plane.

Ralph

In a message dated 4/4/05 8:24:10 PM, dnae(--nospam--at)cox.net writes:
Ralph,
Thanks for replying
the room will be over a garage ( game room)   it is separate building from the house
that the reason I'm considering putting steel beam every 18 ft to 20 ft
and span the floor joists between that( 14 inch deep)
again thanks for your comments
Dave A., P.E. 


----- Original Message -----

From: Rhkratzse(--nospam--at)aol.com

To: dnae(--nospam--at)cox.net ; seaint(--nospam--at)seaint.org

Sent: Monday, April 04, 2005 9:04 PM

Subject: Re: LONG FLOOR JOIST SPAN



A few years ago I had some experience with a TJ-type floor system in a small office building that became a very major bone of contention.  There was excessive vibration throughout the floor, to the point where an acoustic engineer was hired to try to help figure out a solution.  Unfortunately I forget what the solution was, but it was a very difficult problem.  I urge you to be EXTREMELY careful about this.  Try to get the owner's/user's expectations clarified, the use, the occupants' sensitivity, etc.  In other words get the client on board, so that they participate in the discussion over what is good enough, since it's always a tradeoff of cost v. performance.  And DON'T CUT ANY CORNERS!  Trus-Joist doesn't devote a whole page in their catalogue to "Floor Performance" for nothing!

Good luck.  I think you'll need it.

Ralph Hueston Kratz, S.E.
Richmond CA USA

In a message dated 4/4/05 7:53:53 PM, dnae(--nospam--at)cox.net writes:


Hi
I would like to know if I have 28 ft to 30 ft span
I use 18 inch or 20 inch TJI at 16 inch on center
I any one has experience has a problem with

1- vibration
2- noise

and how to limit that
even if I limit the deflection to less than 1/2 inch

thanks in advance

Dave A,.P.E.