Treated vs Untreated Timber: What is Best for Different Projects?

Reading time: 3 minutes

What is treated timber?

Treated timber is a type of wood that has been infused with chemicals through a pressure treatment procedure. These preservatives work to protect the timber from deterioration issues caused by moisture, rot, fungi or interactions with insects.

There are different use classes of treated timber too, which is vital for you to know as you will want to pick the appropriate class to suit the application. Because of this importance, we have a separate guide that explains treated timber grades.

You should be able to recognise treated timber alongside untreated timber, as the former material often has either a brown or green tint due to the type of treatment used.

Four key characteristics of treated timber are:

1. It is a highly durable type of timber for outdoor applications.
 

2. It can withstand exposure to harsh environmental conditions effectively.
 

3. It can last for decades, especially when the material is kept well maintained.
 

4. It can be used for a wide variety of projects.

When to buy treated timber

If you are using timber to construct something that will be based outside or which will be touching the ground, you should always opt for treated timber. 

Here are some ideal jobs for selecting treated timber:

• Decking boards (not in ground contact)

• Fence posts and rails

• Roof soffits and fascias

• Bargeboards

• Landscaping structures

• Raised beds

• Retaining walls

Just remember that if you cut treated timber for any of these jobs, the material will need additional treatment on that area to maintain its integrity.

What is untreated timber?

Untreated timber is wood in its most natural form, with the material cut, cleaned and dried but no chemicals or preservatives added to it.

While this setup means that the product does not have an enhanced resistance to harsh environmental conditions or the effects of moisture, untreated timber is a durable material when used in the correct settings.

When carrying out decorating jobs, you will also be pleased to hear that untreated timber is simple to paint or stain and requires no preparation work.

Four key characteristics of untreated timber are:

1. It is a visually appealing choice, with its natural look allowing its grain and colour to take the spotlight.

2. It is a budget-friendly option of timber.

3. It has a lower impact on the environment compared to treated timber.

4. It is safe to use and handle by those sensitive to chemicals.

When to buy untreated timber

You will want to consider choosing untreated timber when constructing items that will be used in internal environments, as well as for indoor decorative work.

Here are some ideal jobs for selecting untreated timber:

• Cabinetry

• Flooring

• Furniture

• Shelving units

• Stud walls

Now that you know if you need timber that is treated or untreated, be sure to keep browsing through the rest of our expansive and insightful Trade Corner hub. It is filled with expert ideas and advice to improve your approach to any trade project, whether small or large in scope.