We have a workman on site at the moment whose primary hobby seems to be slagging off the work our builders did. Among other things, he is critical that our two supporting walls, that are timber frame with OSB for racking strength, don’t have noggins.

 

I’ve checked our SE drawings and no noggins were specified.

 

The workman is keen to get me to allow him to add in noggins, so I’m looking for some external opinions about this.

 

I don't think he is generating work for self-enrichment - there’s no shortage of work and I know he isn’t even charging me for all of the time he spends on site - I think this is a genuine concern from him.

 

My assurances that the SE would have specified noggins if they were needed have so far fallen on deaf ears, so would value others’ experience - especially anyone with the same design. 
 

thanks!

If you are lining with OSB, then noggins are redundant. Noggins are there to stop the studs twisting and deflecting from vertical load. The OSB will do this instead, and then some!

 

Find him something else to keep him busy!

Edited February 11, 20242 yr by Conor

Based solely on my very limited experience building "stick" outbuildings from 4x2 and 11mm OSB2, I find that if you've only got OSB on one side, then noggins will add noticeable stiffness to the structure, and reduce any tendency to twist.

If you've got OSB on both sides, then it doesn't seem worth it (as long as there's sufficient fixings for the OSB)

But I'm just a DIYer!

1 hour ago, Conor said:

If you are lining with OSB, then noggins are redundant. Noggins are there to stop the studs twisting and deflecting from vertical load. The OSB will do this instead, and then some!

 

Find him something else to keep him busy!

Plus 1 

I do loads of these If the walls are lined one side or both with ply or OSB

You don’t need noggings As Conor as already stated There sole purpose is to stop the studs twisting 

 

If you get the original builder back to inspect there work In sure he could find fault with there’s 

More importantly the OSB is there to give the wall racking strength, i.e. it can't fall over sideways like a pack of cards. A very important feature of a supporting wall.

It just depends on the particular design and the loading. There are no rules.

 

My two storey timber frame build inside an old stone-walled building had noggins (at mid height) in the ground floor walls but not in the upstairs walls. BUT that is probably because the roof structure rests entirely on the the existing stone outer walls. The mid-floor joists rest on top of the ground floor timber frame stud walls so those needed to be much stronger. Both upper and lower level stud walls had a single 11mm OSB sheet for racking and to retain the wood fibre insulation. I'm talking about the outer walls only here - not the internal partitions walls.

 

I'm no engineer but I'm pretty sure that plywood is there to prevent racking and noggins are there to support the vertical studs from buckling under compression. The ply will also help stop the verticals failing but only to a limited extent but that might be enough, depending on the particular overall design.

 

I had one contractor who helped a bit with the work refuse to do some ceiling insulation in a lean'to a particular way (no SE drawings to refer to, just my own past experience) and so I had to tell him to leave it to me to do.

Edited February 11, 20242 yr by Hastings

Thanks all. Helpful as always! I will give the workman the definitive opinion that these are not needed because of the OSB (which I have already told him), and if he continues to insist, I will let him add them once everything else is finished, as long as he only uses leftover timbers  😂

Have him use screws - then you can easily remove them once he's left site  

All edges of a OSB sheet in a shear wall should either be fixed to a common timber (stud or noggin) to the next sheet or be a tongue & groove glued joint.

 

 

This is a simplification method and is potentially a bit conservative, but is the assumed/default installation for a load bearing timber wall. From the IStructE guidance:

 

Quote

all panel edges are fastened either to neighbouring panel edges, via nailing to a common joist, rafter, ceiling tie or batten, or else via a tongue and groove joint glued in accordance with Table 12.1, or else to supports around the wall perimeter

 

Edited February 14, 20242 yr by George