Do you need treated timber for studwork?

In this article, we will be looking at whether you need to use treated timber for studwork.

Studwork is the most common way of building non load bearing, internal walls in properties. They are relatively quick and easy to construct and offer several advantages over solid walls. Some of the advantages include:

  • Lower cost to construct.
  • Easy access for adding first fix plumbing and electrics.
  • Convenient for adding insulation.
  • Easy to achieve a good finish by fixing boards and plastering.

Generally, you don’t need to use treated timber for building stud walls. In most cases something like a standard CLS or scant timber will be just fine. The only exception to this rule, would be areas where there is considerable risks of moisture or condensation.

Most stud walls won’t be at a high risk of exposure to moisture. Therefore, there isn’t much need to pay the extra money for a treated timber.

do you need treated timber for studwork
upstairs and bathroom studwork – All untreated CLS

When is treated timber a good option?

As we already mentioned, a standard untreated timber will usually be sufficient for building studwork. However, there are instances when a treated timber might be a better option.

If you think there is a high risk of moisture, damp, or condensation, then you may opt to spend a little more money and build your wall with a treated wood.

Treated timbers will offer protection from moisture, as well as insect infestation. Therefore, if you think either of these could be an issue, treated timbres can offer extra protection.

One area you may worry about damp, is a stud wall that is in contact with an external wall. This could have the potential of moisture coming in contact with the timbers. Because a solid external wall is exposed to the elements outside, there is a chance it could suffer with penetrating damp.

Penetrating damp could seep through the wall and directly into the timbers, causing issues over time. It could also create condensation in the void behind the studwork if there is no ventilation, this condensation could build up over time. Whether the issue is damp or condensation, the outcome will be the same. Wet timbers, that could suffer from rot and mould.

Insect infestation is another thing to consider. Wood boring insects will not attack treated timbers. This is due to the chemicals that are used to treat the wood. Depending on the species, wood boring insects can attack dry or damp timber. So, if the property has any history of infestation, you may benefit from airing on the side of caution, and just paying a little extra for treated timber.

What about bathroom studwork timber?

Your bathroom is likely the room in your home that will have the highest exposure to moisture. This is caused by steam created during baths and showers. Other rooms in your home will also generate high levels of moisture and condensation. These include your kitchen, utility rooms, or any areas you use to dry clothes.

So, the question is, do you need treated timber in a high moisture area such as a bathroom? The answer to this, is exactly the same as any other room in the house. The studwork is not really at any more risk to moisture exposure, as it will usually have layers of boards, plaster, paint, and tiles, protecting it from any moisture that is produced.

Really, it is at no more risk than a wall that has plumbing pipes running inside it. The main risk here, would be leaks, or burst pipes, and not water penetrating into the wall from moisture in the room. 

With that said, there are extra precautions you would take on a bathroom stud wall. The main difference would be the finish you apply to your studwork.

Moisture resistant surfaces for bathroom walls

On a standard stud wall, elsewhere in a property, you would generally use a standard plasterboard. However, when it comes to a high moisture area such as a bathroom, you would be better opting for moisture resistant boards. These offer additional protection and resistance to the extra moisture in the room.

If you are tiling your bathroom, another alternative to moisture resistant plasterboards, are backer boards. These are cement based boards designed specifically for tiling. Because of the way they are constructed they contain no organic material. This means they won’t support the growth of rot or mould. They are also water resistant so they will stop moisture getting anywhere near your timber studwork.

Also, if your bathroom is tiled, this will add another layer of protection to the timber below. For any areas that are painted, you should also use a water resistant bathroom paint.

Essentially, your bathroom studwork, should follow the same rules as any other stud wall in the property. If you feel there is a risk of extra moisture, or possible insect infestation, then by all means you can use a treated timber. However, it is not a requirement. In most cases standard timber, with the correct moisture resistant surface will do the job just fine.


As you can see, treated timber is not a requirement in most studwork. But as with any job, it is not a textbook answer. You need to consider the risk of moisture and make an educated decision based on the specific situation.

Using a treated timber is completely acceptable, it offers no real negatives. The only downside is that you will end up paying a little more for the timber. However, if in doubt this small extra expense may give you some extra piece of mind.