What is Untreated Timber?
Untreated timber is an often forgotten alternative to its treated counterpart, promising a more natural look, less strain on your purse strings and a notable lack of chemical intervention. However, from longevity to structural integrity, there are many reasons why untreated timber may not be the most apt choice for the job. Take a look through this guide page to find out more!
Contents
Intro
When taking on any project that will involve timber, it’s vital you consider how your timber has been treated - if at all - as this will decide key factors, such as life-span and potential applications. Untreated timber can be a great choice for many projects, namely interior ones where it is safe from weathering. However, for other timber jobs, untreated timber could be a very poor - and potentially dangerous - choice. This guide page will talk you through the benefits and possible negatives of choosing to work with untreated timber.
If you think treated timber may be a better choice for your project and you’d like to find out more about the process or answer any FAQs, check out our What is Treated Timber guide page.
What is Untreated Timber?
As the name suggests, untreated timber is a timber that has been left in its natural state. Although having timber free from any chemical treatment may sound appealing, it means it’s left vulnerable to the environment, including any weathering, fungal-decay and insect visitors.
Due to this, the lifespan of untreated timber is dramatically shorter than its treated counterpart and will only last between a few months and two years. However, just how long it will live is dependent on several factors, including:
- Sun Exposure: With the sun comes ultraviolet rays, which quickly deplete the natural oils in the wood, leaving it dry, discoloured and disfigured.
- Moisture: Any moisture, may that be from humidity, rain or snow, can be absorbed by your porous, untreated timber. This will wreak havoc, causing expansion of the wood and then shrinkage when it dries again.
- Type of Timber: Some timbers are more able to sustain themselves untreated than others, e.g. redwood, white oak, cedar and cypress. Others should really be avoided, e.g. alder, hemlock and pine.
- Other Factors: Other factors, such as exposure to insects and rodents will significantly impact the longevity of your timber. This can also be said for how much contact your wood has with the ground underneath it, as damp earth will often increase its deterioration.
In short, if you have a strong desire to use some untreated timber, it’ll help if you keep the timber for indoor projects, out of direct sunlight, not in a humid environment (think bathrooms) and opt for one of the timbers more apt to tackle life without added support.
Treated VS Untreated Wood
As mentioned above, untreated timber’s lack of chemical intervention can oftentimes be problematic. However, there are also many aspects to untreated timber that still make it a desirable choice.
Let’s take a look at some of the pros and cons of untreated timber below:
✅ Easier to stain: Untreated timber can absorb any woodcare, such as varnishes, stains or oils much easier than its treated counterpart, making it much easier for you to customise your untreated timber however you like.
✅ Reduced health risks: Untreated timber is completely safe to use in close proximity to food (food preparation surfaces, cutting boards, etc). You can also burn untreated timber and not worry about breathing in harmful chemicals or releasing them into the environment. At the end of the day, the ease of mind that comes with using untreated lumber may be worth it. You don't need to worry about potential health concerns, even if the wood comes in contact with your soil or water supply.
✅ Warpage and Shrinkage: Over time, chemicals cause most treated timbers to shrink across their width as they dry out, and their natural wood grains and patterns can be altered from the chemical treatment given. Untreated timber can still shrink and warp, but chemical intervention won't be the thing causing it, meaning if you store it correctly, it can stay like new for longer.
✅ Price: An obvious advantage of untreated lumber is its price; it's much cheaper than treated lumber. Since CCA-treated lumber has been taken off the market, new treatment techniques have been introduced which use high levels of copper, and are more expensive. As a result, the cost of treated wood has risen considerably.
❌ Ageing: Treated wood was designed to defy the effects of natural ageing. As wood is exposed to the natural elements, it slowly breaks down, with moisture speeding up this process even further. If treated, wood can last much longer than untreated wood.
❌ Fire-resistance: Unlike untreated timber, treated lumber can also be fire retardant, taking longer to catch on fire and burning much more slowly when it does, making it safer.
❌ Insects: Many types of treated wood are resistant to insects, like termites, that cause huge amounts of damage and cost homeowners large sums of money. The chemicals used in the treatment process are toxic to insects, so any bug that tries to eat its way through a treated will succumb to the toxins soon after.
❌ Maintenance: Treated timber is a much lower-maintenance choice than its untreated counterpart. The treatment protects the timber for many years, but it is also recommended that you retreat the timber from time to time to protect its longevity.
Applications of Untreated Timber
As a general rule of thumb, untreated timber should be reserved for indoor use, excluding somewhere where there is ground contact, such as the floor of a basement. Here are some applications untreated timber is especially good for:
- For indoor use: Untreated wood can be used within the interior of a home as it is protected against harsh weather conditions and will remain completely dry. Projects such as mouldings and floorboards don’t require treated wood and are also fairly safe from insects.
- For when people are in direct contact with the wood: The chemicals used to treat wood can sometimes hold health risks, especially if you’re planning to be in close proximity to the wood. Untreated wood is great for things such as foldable picnic tables, where one might eat directly off of the wood, for items used to serve food, or for childrens' toys.
- For when you need a combination of different woods: For certain situations, a combination of wood can work well; treated timber should be used in the beams supporting a deck or subflooring, whereas untreated wood can be used for the surface area.
- For outdoor furniture which is not overly exposed: You can use untreated timber for some kinds of playground equipment, such as patio furniture or benches.
- For gardening: Untreated wood can be used for making a raised garden bed, a flowerpot or mulch.
How to Make a Raised Garden Bed
Materials You'll Need:
- Untreated or naturally rot-resistant timber boards (cedar, redwood, or other suitable options)
- Galvanised Screws or Nails
- Tape Measure
- Spirit Level
- Circular Saw or Hand Saw
- Drill or Hammer
- Weed Control Membrane
- Soil
- Compost
- Plants or Seeds
Steps:
- Choose the Location: Decide where to place your raised garden bed. Ensure the area receives adequate sunlight for the plant species you plan to grow.
- Measure and Mark: Determine the dimensions of your garden bed. We suggest measurements around 4 feet wide by 8 feet long, but you can adjust according to your space. Use a measuring tape to mark the corners and edges.
- Cut the Timber: Use a saw to cut the timber boards according to your measurements. If your garden bed is rectangular, cut five equal-length pieces for the sides.
- Assemble the Frame: Arrange the cut timber boards to create the frame of your raised bed. Ensure the corners are square (use a framing square or a 3-4-5 triangle method to check). Secure the corners by drilling pilot holes and using galvanized screws or nails to fasten the boards together.
- Level the Bed: Place a level across the frame to ensure it's even. If necessary, adjust the soil underneath the frame to make it level.
- Install Weed Control Membrane:Lay down weed barrier fabric inside the frame. This will help prevent weed growth from beneath the bed while allowing proper drainage.
- Fill with Soil and Compost: Fill the raised bed with a mixture of quality garden soil and compost. This will provide a nutrient-rich environment for your plants to grow. Leave some space at the top for watering.
- Plant Your Garden: Once the soil is in place, you can start planting your garden. Follow the planting instructions for the specific plants you're growing. Arrange the plants in rows or a layout that works best for your garden design.
- Mulch: Applying a layer of mulch on top of the soil is optional but can help retain moisture, suppress weeds, and improve the overall health of your garden.
- Water and Maintain: Water your plants regularly and provide care as needed based on the specific requirements of the plants you've chosen. Regular maintenance includes watering, weeding, and harvesting.
How to Clean Untreated Wood
Untreated wood furniture that is unfinished or unsealed behaves much like a fresh, unused board, and will be porous and absorbent. Harsh chemical cleaners are out of the question, as they may damage or discolour the wood as it absorbs the liquid. Fortunately, natural cleaning methods offer a safe alternative that is friendly to furniture and humans alike and often comes with a smaller price tag, too.
- Dust: Using a microfiber cloth to gently wipe the surface of a piece of unfinished wood is a simple and easy technique for cleaning the wood. This method is best for surface dirt that is not ingrained very deeply. Just run the microfiber cloth along the surface of the wood to pick up any excess dust and dirt. You can also rub a soft-bristled brush such as a toothbrush, artist's brush or makeup brush into crevices to remove trapped dirt and dust.
- Soap: A squirt or two of natural dish soap mixed into a bucket of lukewarm water serves as a mild cleaner for untreated, unfinished wood. Dip a soft cloth or sponge into the solution and wring most of the liquid out so the cloth is only damp. Wipe the affected areas with the damp cloth or rag, wipe it again with a damp cloth dipped in clean water and wrung out, then dry with a soft, dry cloth. Keep the wood as dry as possible during this process to prevent damage. If the dirty area is difficult to clean, a soft-bristled brush helps to scrub.
- Vinegar: White vinegar is great for removing fingerprints, grime and general dirt left on unfinished furniture. Mix a tablespoon of vinegar into a spray bottle containing a few ounces of water, then squirt the solution onto the affected area, wiping away with a damp cloth. Wipe the cleaned area with a dry cloth afterwards to keep the moisture from soaking into the wood. A stronger vinegar solution, such as 50/50 vinegar and water, may be used for heavier cleaning.
- Ice: Chewing gum or pine tree sap creates a sticky mess that may seem difficult to remove from wood without causing damage to the furniture. Place a few ice cubes in a zippered sandwich bag, then set the bag over the area until the gum or sap hardens. Carefully chip the hardened mass away with a plastic knife or spatula.
For further information regarding the legal standards surrounding the treatment of timber, please see the Timber Preservation Page provided by the NHBC (National House Building Council).
If you’d like more information on what applications treated timber is apt to tackle or what different kinds of timber are available, take a look through our other timber guide pages: