# metal stud limiting height - what is it?



## syarn (Jul 6, 2012)

if I am building a demising partition wall with 6" metal studs from concrete slab to bottom of metal deck.

the bottom of the deck is approx. 19' AFF.

what is the typical load one should use - 5, 7.5 or 10 psf?

what is the typical min. allowable deflection - l/120, l/240 or l/360?

does limiting height effect what gauge, size & spacing of metal stud I can use?

e.g. is a 6" metal stud 20 gauge (.033) at 24" oc is OK only for the all load levels at l/120 but begins to fall short at stiffer deflections;


----------



## steveray (Jul 6, 2012)

Use 120 or 240 if it is a stiffer finish per 1604.3.....Personally....I'd use 18ga. on a 20' tall wall.....esp 24"OC...


----------



## Big Mac (Jul 6, 2012)

If it is an interior wall with no load other than the sheetrock, a minimum of 5PSF should be used.  If other loads such as shelving are probable, the loading shouldl go up accordingly.  if the wall is in a warehouse where doors are frequently left open and the wall could be subject ot wind loads, that should also be considered.

Many structural steel manufactuerer's have matrixes for these type of issues.  Depending on loads, spans, etc. they will tell you what size and gage of metal stud is needed.


----------



## Mark K (Jul 6, 2012)

Since this is not within the scope of the IRC that IBC would govern.  The studs should be designed by an architect or engineer who should be able to answer your questions.


----------



## GCtony (Aug 2, 2012)

USG has a chart showing limiting heights for interior partitions.  A 6" 25 gauge stud 16" OC with single layer of GWB boths sides can be 20' tall.  Same deal but 24" OC, drops down to 15' tall.   20Gauge 16" oc can be 33' tall.  If you add the horizontal stiffeners, the u shaped steel that snaps into the knockouits of the stud, allows you to increase the height.  I don't know the technical name but we call it "black iron"

A trade related thought; 25 gauge studs shouldn't be used when type x GWB is being attached. Since the X is harder than regular, screws don't sink in well and a significant number strip out of the stud. Course thread "wood" screws are better but if you need the type x, go with 20 gauge studs.

http://www.usg.com/documents/construction-handbook/chapter2.pdf


----------



## brudgers (Aug 3, 2012)

The SSMA Product Technical Info covers it:  http://www.ssma.com/filebin/pdf/SSMA_Product_Technical_Info_Catalog_2011_FINAL.pdf

  Requiring a design professional to read the chart for non-bearing partitions is silly.


----------



## khsmith55 (Aug 3, 2012)

If my memory serves me correctly the code requires a lateral load of 5psf. After "sizing" the studs with the links mentioned above you will need to address the floor and roof connections (about 47.5plf). You may not need a RDP to "read the charts" but they may look at the total assembly like the top and bottom connections. You may be surprised at how onerous the connections are after proper design.

Ken


----------



## brudgers (Aug 4, 2012)

At the thicknesses required for a 19' span, the screws will handle the lateral loads for the partitions.

  In other words, the screws are not the limiting factor for interior partitions.

  That's what makes it a system.


----------

