Noggins are used to add stability and rigidity to a stud wall or timber joists. They also provide an area to fix the edges of plasterboards, as well as providing additional support for the boards and finished plaster.
Whether you use noggins or not, can vary based on several factors. For example
- Centers used to space timbers – This is usually between 400mm – 600mm
- Thickness of the timber – This could range anywhere from 63mm CLS studwork timber. All the way up to 235mm floor joists.
- Plasterboard thickness – The most common sizes are 9.5mm and 12.5mm. You will also see 15mm, although less frequently.
If you are building a stud wall with standard 400mm centres, then in my opinion, you should always use noggins. Even if you are boarding with 12.5mm plasterboard.
12.5mm boards will be more rigid, and there is less risk of plaster cracking. However, the edge of the board is still not sat on anything. If something or someone fell into the wall, the plaster could easily crack, or even snap.
This is regardless of timber thickness. Even if the wall is made with 4×2 and really robust. The edge between the studs, with no noggins behind it would still be weak.
Let me end this section by saying one thing.
Adding noggins is only going to have a positive result on the frame they are added too.
The wall, ceiling, or floor will be stronger, plasterboard joints that land on noggins will be stronger, and they will reduce natural movement in the timber. This means less twisting, bowing, and warping.
The only downside is the extra time and effort. Admittedly, there is also a potential small cost for additional timber. However, if you are building a wall, or fitting joists, there is almost always off cuts. This means the cost to add noggins is often zero.
Times you don’t need noggins for 12.5mm boards
Personally, I would nearly always add noggins to walls. However, there are a few instances, where they might not be needed
Also, there is an argument they can be left out of ceilings in some instances.
No noggins in walls
When it comes to walls there are only a couple of instances where I wouldn’t use noggins.
- The wall is very small (maybe not full height) and there will be no plasterboard joints.
- A wall is built with thick 4×2 timber and again no joints are present. This could be something like floor to ceiling dry lining boards. In this case all the joints would be vertical.
In both of these scenarios you probably don’t need noggins. Although I may add them to the latter example, if I had the timber spare. Again, like I mentioned before, it is a net positive to the strength of the wall. So, if the timber was there, I would use it and add them.
No noggins in joists
Joists are generally made with thicker timber. Even ceiling joists that have no weight above them tend to be at least 4inch. Also, it is far less likely that joints will be banged and damaged on a ceiling.
For these reasons, there is a slightly better argument for not adding noggins in some cases.
If you are adding 12.5mm plasterboards, you will not always need noggins. If joists are spaced at 400mm centres, the edge of the board should have sufficient support. This should avoid movement and issues such as cracks in the plaster joints.
However, if your joists are spaced at 600mm centres, a 12.5mm board will not be sufficient. In this case you will either have to add noggins. Or alternatively use a thicker board, such as 15mm.
One other thing you should consider, is the size of the ceiling, and the number of plasterboard joints. If it is a particularly big ceiling, the chance of movement in one or more places is greater.
Even if the joists are thick enough to span the distance following building regulations. And even if the joists are spaced at 400 centres, there is still a greater chance of issues. There will simply be more potential points of failure.
Conclusion
Even with a 12.5mm plasterboard, noggins are still recommended in most instances. There are times when you can get away without them, but generally it is better to have them fitted.
Certainly, when you are building a stud wall, there are very few instances where you wouldn’t add noggins. In most cases they are essential to add additional support, and fixings for plasterboards
