Stringers needed or not ?

Beside the fact that they are needed for 10ft+ walls (by code requirements). From an acoustic standpoint should one use stringers in studio walls construction? Since they stiffens the walls my guess is that they should be used but from all the post i see here most walls are built without them .Search all morning on this site for a clear info on this topic, and ended more confused than before. thanks For those who may wonder what i call a stringers is : it's those perpendicular pieces of woods places in between each studs about the middle of the wall.

i think there is a lot of conflicting ideas about whether or not the rigidity is better or worse for purposes of acoustics. i'm not sure if any one has performance metrics on walls with and without them. you want them on either side of a framed door, and if the wall is load bearing i use them. i generally don't use them on non-load bearing treatment walls unless i'm dividing cavities horizontally, or using vertical or less-than-full-height assemblies which need a nailer.

Hi Glenn, Merry chrismas BTW !

think there is a lot of conflicting ideas about whether or not the rigidity is better or worse for purposes of acoustics. i'm not sure if any one has performance metrics on walls with and without them.

Well i'll add even on this site there seem to be some contradiction about the stiffness of a wall conctruction in a studio. I thinks there should be a topics added in the reference aera about that.

you want them on either side of a framed door, and if the wall is load bearing i use them. i generally don't use them on non-load bearing treatment walls unless i'm dividing cavities horizontally, or using vertical or less-than-full-height assemblies which need a nailer.

Thanks for that info Glenn. Just for the record, around here in regular house construction, they use strigners in all less than 2X6 walls (load bearing or not) So the inside division of the house made of 2X4 will use strigners but the outside 2X6 loadbearing walls won't. I Talk a lot with various carpenter and from a structural standpoint, thay all say that they stiffens the wall by making it act as a whole. This obviously is not an acoustic engineer answer but it gives a clue... I wonder what's Rod opinion on this ?

Well, 1st - I have never heard the term used as it's being used here....... According to "Architectural Graphics Standards" which is an AIA (Architects of America) publication (In the USA it is basically the bible of architecture) a stringer is the part of a staircase that sits in a vertical manner and which supports the stair treads and risers. Typically you would see at least part of this at the 2 sides of a stairwell - although there might well be intermediate stringers placed beneath the threads / risers as needed for support. It is also defined as a member (or members) used to support cross-menbers in floor openings Thus you would install a couple of pairs of stringers abvout 3' apaert - locate your stairwell within the length of this opening - and then install the crossmembers required to complete the stairwell opening. I have not heard the term used other than as explained for these 2 (very different) cases. We would normally call (what I believe you are refering to) these members "blocking" when installed in walls - (Bridging if installed in floor framing) OK - that having been said - for residential construction: blocking (placed within a wall cavity) is not a requirement here in the states for bearing partitions UNLESS the partition is: A) An exterior wall and B) Has structural sheathing installed on it in such a manner that a horizontal joint in the structural sheathing does not have a solid nailing backer AND c) The area of construction is within a 110mph wind loading zone. Commercial construction is as required by best engineering practices. As to the question at hand - does the stiffening of a wall increase it's TL value....... Answer = possibly, maybe - maybe not, This much can be verified through the testing performed in IR-761 ( http://irc.nrc-cnrc.gc.ca/pubs/fulltext/ir761/ ) - all else being equal - a wall constructed out of 2x6 installed at 24" centers will have a slightly lower set of TL values in the LF range (with a few exceptions) than a wall built with identical drywall and insulation constructed with 2x4's @ 16" centers. Now - although it might appear that the 2x6 wall (as a whole) is stiffer than the 2x4 wall would expect to be - this would only apply to the wall face as a whole - although the drywall in each individual bay would expect to be less stiff. So I don't see any strong conclusion that installing blocking in bays (which would stiffen the drywall in each individual bay) would increase TL values in the LF range (which is always the range we are concerned about). BUT - this is strictly my reasoning and following what I consider a logical path. I can find no hard test data to support or disprove the theory. So this ends up being just an unanswerable question in the field of acoustics until someone winds up footing the bill to determine reality through the testing of various wall tpes with this specific question in mind. Sincerely, Rod

In Australia we call them noggins - they are compulsory in all wall framing at 4' spacing which also coincides with drywall sheet sizes.

John Sayers wrote:

In Australia we call them noggins - they are compulsory in all wall framing at 4' spacing which also coincides with drywall sheet sizes.

John, That makes perfect sense to me - unfortunately - here in the states - they won't let us space a stud (even in a non-bearing wall) greater than 24". So you never see that condition.......... And thanks fopr sharing the termiology........ Rod

John Sayers wrote:

In Australia we call them noggins - they are compulsory in all wall framing at 4' spacing which also coincides with drywall sheet sizes.

That is 4 feet from ground elevation?

xSpace wrote:

That is 4 feet from ground elevation?

Yep, from the floor up, every 4' you have one noggin. 12' ceilings ==>> two noggins.

4' spacing which also coincides with drywall sheet sizes.

And there are insulation batts made to fit, too. Reduces downward "settling" of the batts, I would think. And less cutting if you're installing in a... nogg-ed wall.