Reinforcing Long Span Ceilings

I'm just curious from reading everything. Please forgive me because I am a construction newbie just trying to wrap my head around some of these methods. How do you reinforce a long span ceiling that is longer than the 8' -10' studs. Does this require a support beam of some kind or do you just screw 2x4s together? What if you are working with metal framing? I guess you need a heavier gauge to support the ceiling, but what do you do if your ceiling span is say, 30' x 40'? Do you weld the metal studs together? Doesn't it lose rigidity the longer it is?

You use the correct dimension of timber for the span and load that you have. My suggestion for that kind of question would be to call in a structural engineer. If you don't know what you are doing with hanging really heavy objects above your head, then you need advice from a professional guy who does know what he is doing, and can do the relevant calculations. This is one area where you don't want to be guessing: Having a few hundred kilograms of stuff fall on your head is not going to be good for your health... - Stuart -

speedo wrote:

I'm just curious from reading everything. Please forgive me because I am a construction newbie just trying to wrap my head around some of these methods. How do you reinforce a long span ceiling that is longer than the 8' -10' studs. Does this require a support beam of some kind or do you just screw 2x4s together? What if you are working with metal framing? I guess you need a heavier gauge to support the ceiling, but what do you do if your ceiling span is say, 30' x 40'? Do you weld the metal studs together? Doesn't it lose rigidity the longer it is?

You are not going to span 30 to 40' with any conventional framing without introducing columns - even for a ceiling load with no live load on it that would take a fairly deep truss member........ If you have existing structure above you can always install isolation hangers (properly sized for the total dead loads) at intermediate locations to carry the loads while maintaining smaller lumber dimensions (I have used this in design so as to have 2x4's sitting as little as 1" below an existing ceiling to maintain maximum headroom.) Everything then begins with your hiring a structural engineer to determine if the existing ceiling can handle the spot and total loads you are going to add to it, and would finish with an acoustical engineer designing the ceiling (and possibly walls) to properly isolate. Sincerely, Rod

OK, I am actually going to hire an engineer and contract this job out. I'm just still trying to get my head around some of the basics and get my questions from Rod's book answered before I go in tell them what I want. Another (prob stupid) question concerning metal framing: Can you use metal framing for an isolated ceiling? All of the examples of metal framing I've seen online are really just for walls. In the case of ceilings, the metal studs are reinforced by an existing wood structure. Can an isolated steel frame support the drywall ceiling placed on load bearing walls? Can steel framed walls even support the ceiling? The studs seem kind of flimsy.

speedo wrote:

OK, I am actually going to hire an engineer and contract this job out. I'm just still trying to get my head around some of the basics and get my questions from Rod's book answered before I go in tell them what I want. Another (prob stupid) question concerning metal framing: Can you use metal framing for an isolated ceiling? All of the examples of metal framing I've seen online are really just for walls. In the case of ceilings, the metal studs are reinforced by an existing wood structure. Can an isolated steel frame support the drywall ceiling placed on load bearing walls? Can steel framed walls even support the ceiling? The studs seem kind of flimsy.

The steel studs you are referring to as "flimsy" are light guage (probably 25 ga.) framing that cannot take a load. Structural framing (the guage is dependent on the unbraced stud height and total load) is heavy guage - ie.: 20 guage - 18 guage, etc, Anything used on a ceiling is joist - studs are only used in walls........ correct termonology help you a lot when it comes to being able to comminicate effectively. Again - the span is the same as it is for wood - the frame depth and guage are dependent upon the total load (dead and live). Rod The short answer is "yes" you can support

Thanks Rod, Yes, 25 gauge is what I have been looking at. So I take it the entire structure (including the walls) will need to be a much heavier gauge? You mentioned in your book that the lighter gauge will have a higher STC rating (equivalent to wood with RC) so I assumed it would be OK for walls, but maybe you were referring to light load carrying walls - or simply non load carrying partitions within the space. Thanks again.