Do I Need Treated Timber? #
In an era of increasing environmental and safety concerns, many customers are starting to question whether having treated timber is necessarily the right call for their upcoming project. While it’s certainly the industry standard, and there are a considerable number of benefits that can come from different timber treatments or coatings, we at Logie often find this all comes back round to a central question – do I really need this? The long waiting periods for treated timber; the hazardous chemicals involved in the process; and the danger it can pose to children or pets are all good reasons to question whether you should get your wood treated or not.
The Risks of CCA Timber #
The primary issue with treating timber comes in the fact that a core aspect of timber treatment has been suffusing chemicals into the wood. Ever since the process began in 1938, it has involved chemicals which pose inherent safety risks not only for the labourers working on the timber, but also to the families inhabiting houses using this wood in their houses. Many of the chemicals sprayed onto treated wood are creosotes, which include phenols, cresols, and polycyclic aromatic hydrocarbons. Not only were none of these chemicals designed for indoor usage, but, if inhaled or exposed to in sufficient quantities, they can cause severe medical issues. These include seizures, vomiting, blackouts, and excessive swelling.
For professional labourers on construction projects (for instance, building timber-framed houses or fencing), these chemicals rarely pose a present danger. This is because you can expect builders to be using up-to-date safety equipment, dispose of sawdust and waste properly, wear masks and organise their construction in a regulated fashion that enables clean cuts and minimal wastage. However, you can often rarely apply most of these same standards to home construction, such as DIY builds, home deck assembly, or modification of timber structures, and it’s here that the danger of excessive chemical exposure lies.
Tanalised Timber #
Among the many methods of timber treatment, tanalised timber is the most generally common in terms of new timber builds. Its mixture includes copper, arsenic, and chromium. These chemicals are all individually dangerous, but their mix becomes relatively safe once mixed into the timber. However, none of these three materials can be sourced ethically, sustainably, or safety. The need for sustainability legislation in the copper industry has been a long-running issue in the mining world. Chromium’s safety issues have long been a concern in the world of tanning, where 90% of leather is tanned using it, and its toxicity has resulted in numerous factory closures in Europe and the US, as well as the pollution of numerous African waterways. As for arsenic’s safety issues…well, you can probably fill in that blank yourself.
Governmental Pressure #
While the industry has long since assured its customers of the inherent safety of tanalised timber (sometimes called CCA timber), many countries have already begun legislating against it. Some nations have already banned it outright, including Denmark, Switzerland, Vietnam and Indonesia. The EPA have banned it entirely for use in residential projects, many Canadian firms refuse to work with it for interior projects, and it’s now illegal to import CCA-treated wood into the EU. The UK, on the other hand, has been dragging its heels on the matter. Few practical changes have been made to restrict its usage.
CCA Timber & Your Home #
If you’re thinking of buying timber that’s been pressure-treated, you might want to reconsider if your project a) might be involved with young children, or b) is close by to any running sources of water. The chemical nature of CCA makes it unviable for use in any kind of children’s playground equipment, as well as for hand-rails, door-handles, or anything else children might touch frequently. Making any kind of boat or jetty with tanalised timber would be a disaster waiting to happen, as constant water pressure can leach the chemicals out from the pores of the wood and into the water, where they could have a devastating effect on local wildlife.
The Ecosystem #
This could even be an issue if you live in an area with very consistently heavy rain, as the chemicals could leach into your soil, contaminating plants or crops. When you set a timber structure into the soil, in addition to any safety concerns, you also need to be aware that you’re introducing a new biological product into a tight-knit ecosystem. Even cut wood products breathe, contracting and expanding in weather; they respond to the rain and the frost; they can be home to insect or bird species that form a vital part of your local ecosystem. If making sure your climate and ecological impact is minimal is a concern to you, you might well want to steer clear of planting CCA timber products outside.
Chemicals Inside The Home #
The same thing is equally true for interior products. While the chemicals in CCA wood stand the highest chance of leaching outside, with rapid moisture exposure, they can similarly leach inside, in the right conditions. Chopping boards pose a huge risk, as they’re often covered in both moisture and food. Experts also advise against using them for dining-room tables, or bed-frames, especially if you live in an area of high humidity. Many treatments, including CCA, also make wood more flammable than it is naturally, making indoor flooring or decking using CCA an unnecessary fire hazard.
All pressure-treated timber, regardless of the treatment, require the wearing of protective gear by the labourers involved. The mere fact that this gear is necessary is often cause for many concerned and environmentally focused hobbyists to argue that all pressure-treated timber is unsafe for indoor use. While this isn’t necessarily true, it does always pay to be cautious; and if you want to work on a small-to-medium scale project that doesn’t substantially interrupt your home life (for instance, working on a table or deck without demanding your family stay out of the garden or wear PPE), you might want to consider avoiding treated timber. Any time you cut or drill into CCA-treated timber, you’re exposing yourself and anyone around you to toxic sawdust. This could even occur as a result of accidental damage, such as children play-fighting on your deck, or a lawnmower malfunction. If you’re living alongside CCA wood, you can never forget that it’s toxic; and the peace of mind that can come from not having that weight is often a good investment for your home.
Alternative Treatments #
Alternatives And Their Problems #
Many alternative timber preservatives have been developed in response to customer and governmental concerns about CCA. However, these can often pose their own issues. Many replace the chromium and arsenic with higher levels of copper, which makes them more corrosive to metals. Also, as a heavy metal, the copper in these treatments remains equally dangerous to soil, plant, and especially tree health if it leaches out into the soil and contaminates the surrounding area.
Many companies are replacing CCA’s with ACQ treatment. ACQ, or Alkaline Copper Quaternary, is graded safe for indoor use, and generally is. However, it’s still at prone to leaching when exposed to excessive quantities of water, so be careful when placing it anywhere it might be exposed to constant water or heavy amounts of rain.
Another alternative is borate-treated wood. Borate, a largely colourless and odourless chemical, penetrates deep into the wood. Its relative safety can be assured by the fact that borate is an essential chemical in the process of plant life and plant cell reproduction. However, this treatment still isn’t considered food-safe, making it unviable for a lot of indoor kitchen/dining-room projects, and those with young children should still be cautious.
Why Use It At All? #
More Plank For Your Buck #
The reasons why the industry used CCA for so long, and why it’s now so insistent on new forms of pressure-treatment, are relatively simple. Both of the main lines of argument boil down to economics. Pressure-treated lumber, when sold in bulk, is cheaper. If you’re bulk-buying timber, or buying from a supplier who bulk-buys, you could save up to 30-40% on the cost of your order. The other factor is simply that it’s stronger, and so requires less maintenance. Depending on the nature of your project (namely where it is and what kind of weather it might be exposed to), if you’re using treated timber, you might well not even need to apply an additional coating or staining material. The treatment enhances durability, confers a good level of scratch and stain resistance, doesn’t need any special maintenance or re-application, and the very toxicity of its nature also means it kills off insects and fungi that try to make their home inside it.
EPA Findings #
Despite the environmental factors, there have been legitimate reasons for using pressure-treated timber. When the EPA conducted their case study, they agreed that pre-existing CCA timber structures didn’t need to come down and found that most structures in urban areas (especially those on concrete bases) had caused minimal, if any, environmental contamination.
Alternatively…No Treatment? #
Why Not Treat? #
However, if you have young children in the home; live somewhere rural and care about the local ecosystem; live somewhere with heavy water flow, either from a waterway on your property or heavy rain; have a project in mind that involves your wood directly meeting the ground; are concerned for your health or your family’s when it comes to toxic sawdust; or even just want to make a stand against corrupt and environmentally toxic industrial practices, you might at this point be looking for an alternative. While some of the other treatments we’ve mentioned might suit you fine, we also want to raise the possibility that you could just…not treat it at all.
Scottish Timber, Scottish Homes #
We’ve always had the ability to make natural wood products that suit our climate and environment with native trees; but, if anything, this is lost knowledge. Often, from suppliers, you’ll hear that Scottish timber simply isn’t good enough to meet the demand for construction. Why? There are numerous great examples of modern-build projects that have been made sustainably and without treatment. The key is just knowing which wood type to use.
Douglas Fir #
Our personal blanket recommendation is Douglas fir. It’s sturdy, it’s reliable, it holds up very well to harsh weather conditions, and it’s easily sourced from all number of estates across Scotland. While CCA wood poses a risk for indoor projects, natural Douglas fir has no such issues, and it’s ideally suited for joinery, decking, cladding, and furniture.
However, if you’re somewhere where excessive rain is a little more of an issue, or if your project will be in prolonged contact with water, you might want to try larch. Larch works at its best in large-scale projects, where longer beams of larch can benefit from their inherent tensile strength to take drilling and nailing with ease.
If scratch or water resistance is a concern of yours, you might want to look into coatings. TreaTex, our personal recommendation, offers high-quality finishes and oils for both Douglas fir and larch, that can imbue the already strong timbers with UV and water resistance. TreaTex products are sustainably sourced, and entirely free from toxins, making them safe for children (if not always food-safe). They’re not only safe, but quick drying, meaning even this stage of your project doesn’t need to be disruptive to a home environment.
If you are going to use untreated timber, be mindful about moisture content. Make sure that the wood you get has been dried properly. Wood that’s dry (under 17% moisture content) won’t rot, but prolonged exposure to water or high humidity can be an issue (especially for species that don’t have natural water resistance). If your timber is exposed in this way, identify the areas of highest moisture, and work to dry it out as quickly as possible.
Hazard Class #
If you’re planning on using a timber that’s not Douglas fir or larch, make sure that it’s at least of a roughly similar level of durability. If your project is load-bearing in any way (flooring, decking, etc), make sure that the timber is of an appropriate Hazard Class for such construction.
Return To Nature #
While the use of untreated timber in construction was something of a rarity throughout the 20th century, it’s becoming increasingly popular again as the modern industry grows to reflect consumer concerns about the environment, sustainability, and aesthetic choices. Many modern cladding projects in particular have started to leave the wood untreated, allowing a natural, silvery patina to develop in response to environmental conditions. Although it might instinctively seem like a dangerous impulse to leave your wood untreated, much of that hesitation has just come from years of it being the standard industry practice. So long as you get the right wood for your project, treat it properly, and do your research ahead of time, there shouldn’t be any issues with your project using untreated timber; and your local area, the planet, and your family will likely thank you for it.