Pressure-treated wood is lumber that has undergone a particular process to enhance its inherent qualities. The treatment involves infusing chemical preservatives into the wood to boost its resistance against decay, insects, and rot.
This unique procedure increases the longevity and resilience of the wood, making it an excellent alternative for outdoor projects and constructions exposed to extreme weather conditions.
Untreated wood is susceptible to decay, rot, and insect infestations, limiting its usefulness in outdoor applications. Pressure-treated wood, on the other hand, offers enhanced durability and resistance to these issues.
While untreated wood may have an appealing natural look, its lifespan is considerably shorter than pressure-treated wood.
Types of pressure-treated wood
Various types of pressure-treated wood can be classified based on the preservatives used and the intended applications. Some common types include:
Alkaline Copper Quaternary (ACQ)
A water-based treatment that combines copper and quaternary ammonium compounds for resistance to decay, insects, and rot.
Copper Azole (CA)
A treatment similar to ACQ uses copper and azole biocides to protect against decay, insects, and rot.
Micronized Copper Azole (MCA)
A newer treatment uses micronized copper particles and azole biocides to enhance protection and a lighter color.
Chromated Copper Arsenate (CCA)
A treatment that uses chromium, copper, and arsenic to protect against decay, insects, and rot. Due to environmental concerns, CCA-treated wood is now primarily used for industrial and agricultural applications.
Each treatment chemical offers different levels of protection, environmental impact, and color.
The treatment choice depends on the wood’s intended use and desired appearance. For instance, ACQ and CA treatments are ideal for residential and commercial applications, while CCA is more suitable for industrial and agricultural use.
What is Impregnated or pressure-treated wood?
Impregnation and pressure treated wood are the same. The process is identical and is usually performed outdoor for rot protection. The two terms used to describe the same wood treatment:
Impregnation is done using impregnating agents; a well-known brand of an impregnating agent is ‘Tanalith E.’ This brand has been known since the 1940s. Pressure-treating is when a product like ‘Tanalith E’ is used.
When impregnating wood, the wood is treated with a combination of chemicals, with copper as the main component.
The metal copper protects the wood excellently against wood rot and insects. The other added substances preserve the wood against other forms of attack, which the copper does not influence.
Impregnated wood often has a characteristic green glow, and this is due to the copper that is now in the wood.
Two common ways to impregnate wood
are dipping or applying vacuum pressure-treated wood. In both cases, an impregnating agent is used to preserve the wood, and the way is different.
Impregnation of wood by dipping
The dipping technique is a popular technique for preserving garden wood. This technique is used for black impregnation.
Wood is immersed in an impregnating agent in a large bath for a few minutes. This allows the wood to absorb as much impregnating agent as possible. Sometimes the wood is so fresh and, therefore, still a bit damp that it absorbs the impregnating agent less well.
The quality of the dipping technique, therefore, depends on the moisture content in the wood. It also makes it difficult to get an even color.
Nevertheless, this method gives the wood a beautiful black color and leaves the wood structure visible. When planks are placed undercover, for example, under a roof, they will discolor to a minimum.
When impregnating through dipping, the wood is immersed in a bath in impregnating agent. The wood is then given a few minutes to absorb the impregnating agent.
This treatment method is very popular but produces less durable wood than wood impregnated under vacuum pressure.
Impregnation of wood by vacuum pressure treatment
Wood is placed in a large boiler, which is then vacuumed. The tank is then filled with an impregnating agent, ‘pressed’ into the wood by the pressure; that is why it’s said as “pressure-treated” wood.
This ensures that the impregnating agent penetrates deep into the wood to protect it better.
A plank impregnated under high machine pressure lasts about 2x longer than a dip-impregnated garden plank.
Pressure-treated wood chemical
The main component is copper, to which other chemicals have been added. Copper is excellent protection against wood rot and insects.
The other chemicals (biocides) protect against wood rot that copper has no influence on, such as brown rot fungus.
Benefits of Pressure Treated Wood
Durability and resistance to decay
One of the most significant advantages of pressure treated wood is its enhanced durability.
The preservatives infused into the wood during treatment protect it from decay, rot, and insect infestations, which are common issues untreated wood faces.
This extended lifespan makes pressure treated wood a cost-effective choice for outdoor projects.
Cost-effectiveness
While pressure treated wood may be slightly more expensive upfront than untreated wood, its durability and resistance to decay make it a more cost-effective option in the long run. The reduced need for repairs and replacements can save both time and money.
Strength and structural advantages
Pressure treated wood possesses excellent strength and structural integrity, making it suitable for load-bearing applications such as decking, fencing, and framing.
The treatment technique does not weaken the wood’s intrinsic strength, allowing it to handle big weights and resist harsh weather conditions.
Ground contact suitability
Ground contact can harm untreated wood, exposing it to moisture and decay-causing organisms. However, pressure-treated wood is designed to withstand direct ground contact without compromising its structural integrity or lifespan.
Applications of Pressure Treated Wood
Best pressure treated wood for decks
Because of its longevity, strength, and resistance to decay, pressure treated wood is a great choice for decks and other outdoor constructions.
The desired appearance, budget, and local construction standards will determine the pressure-treated wood appropriate for decks.
Common choices for deck construction include ACQ and CA-treated wood, which offer excellent protection and a natural appearance.
MCA-treated wood is another popular option, providing enhanced protection while retaining a lighter color.
Ground contact lumber vs pressure treated
When constructing a deck or other outdoor structure, choosing the right type of lumber is essential.
Ground contact lumber is specifically designed for applications where the wood directly contacts the ground.
In contrast, pressure treated wood is intended for a broader range of applications, including ground contact.
Pressure treated wood is often preferred for decks and outdoor structures due to its enhanced durability and resistance to decay, rot, and insects.
Can you use pressure treated wood for crafts?
While pressure treated wood is a popular choice for outdoor projects, it may not always be the best option for crafts and indoor furniture.
The chemicals used in the treatment procedure can be hazardous, especially if applied near food or in areas where humans frequently contact the wood.
However, if the proper precautions are taken, such as sealing the wood with a suitable finish, pressure treated wood can still be used for certain crafts and indoor furniture applications.
Pressure treated wood for bed frames and dining tables
Pressure treated wood can be used for bed frames and dining tables, but it is essential to consider the potential risks associated with the chemicals used in the treatment process.
Applying a durable finish to the wood is recommended to minimize these risks, which can help seal in the chemicals and create a barrier between the wood and users.
Additionally, ensuring that the wood is thoroughly dried before use is crucial, as excess moisture can cause the chemicals to leak.
Using pressure treated wood for framing and roof rafters
Because of its increased durability and resistance to decay, rot, and insects, pressure treated wood is a great choice for framing and roof rafters in construction projects.
This added protection is particularly beneficial in areas with high humidity or where wood is exposed to moisture, such as basements and crawl spaces.
Following local building codes and guidelines is essential when using pressure-treated wood for framing and rafters to ensure a safe and sturdy structure.
Marine grade pressure treated lumber
Marine grade pressure treated lumber is specifically designed for use in marine environments, such as docks, piers, and seawalls.
This type of pressure treated wood undergoes a more rigorous treatment process to provide enhanced protection against the harsh conditions in marine settings, including saltwater, high humidity, and extreme weather.
Marine grade pressure treated lumber is typically treated with higher concentrations of preservatives, ensuring it can withstand the demanding conditions of these environments.
Safe Handling and Use of Pressure Treated Wood
While pressure treated wood offers numerous benefits, handling and using it safely is essential. To protect yourself and others, take the following precautions:
- Wear gloves, long sleeves, and eye protection when handling pressure treated wood.
- Always work in a well-ventilated area to minimize exposure to chemical fumes.
- Use dust masks and respiratory protection when cutting or sanding treated wood to prevent inhaling wood dust.
- Seal cuts and drilled holes in pressure treated wood with a wood preservative.
- Dispose of pressure treated wood waste properly, as it should not be burned or mixed with regular household trash.
What should never be done with pressure treated wood
- Avoid the following actions when working with pressure treated wood:
- Burning pressure treated wood, as it releases toxic fumes.
- Using treated wood in direct contact with food or water, such as garden beds or cutting boards.
- Using pressure treated wood for children’s play structures without sealing it properly.
- Disposing of treated wood waste in regular household trash or compost.
Pressure-treated wood poisoning symptoms
Exposure to the chemicals in pressure treated wood can lead to various symptoms, including:
- Irritation of the skin, eyes, and respiratory system.
- Nausea, vomiting, and abdominal pain.
- Dizziness, headache, and confusion.
- In extreme cases, difficulty breathing and seizures.
If you suspect pressure-treated wood poisoning, seek medical attention immediately.
Dangers of using pressure treated wood indoors
While pressure treated wood is an excellent choice for outdoor projects, using it indoors can pose risks. The chemicals in treated wood can off-gas and leach into the indoor environment, potentially causing health issues.
Additionally, the wood’s moisture content can lead to issues with indoor humidity and mold growth. If using pressure treated wood indoors, ensure proper ventilation and sealing to minimize these risks.
Dangers and Hazards of Pressure Treated Wood
Toxic fumes emitted by pressure treated wood
Pressure treated wood can emit toxic fumes, particularly when burned or exposed to high heat. These fumes contain harmful chemicals, such as arsenic and chromium, which can cause serious health issues if inhaled.
Always avoid burning pressure treated wood and ensure adequate ventilation when working with it.
Duration of toxicity
The duration of toxicity in pressure treated wood depends on several factors, including the type of treatment, wood species, and environmental conditions.
Generally, the chemicals in treated wood can remain active for several years, with some studies suggesting up to 20 years or more. However, the risk of exposure decreases over time as the chemicals break down and leach out.
Indoor use risks
Using pressure treated wood indoors can pose several risks, such as:
- Off-gassing of chemicals can lead to poor indoor air quality and potential health issues.
- Leaching chemicals into surrounding materials, including flooring, walls, and furniture.
- Moisture-related issues, such as mold growth and increased humidity levels.
To minimize these risks, ensure proper ventilation, sealing, and moisture control when using pressure treated wood indoors.
Pressure treated wood leaching chemicals
The chemicals in pressure treated wood can leach into the surrounding environment, particularly when the wood is in contact with moisture or soil. This can lead to contamination of soil, groundwater, and nearby plants.
To minimize the risk of leaching, use appropriate barriers or containment methods, such as lining garden beds with plastic or using untreated wood for direct food contact.
How long does pressure treated wood remain toxic
As mentioned earlier, pressure-treated wood toxicity can last several years, with some studies suggesting up to 20 years or more.
The risk of exposure decreases over time as the chemicals break down and leach out. Proper maintenance, such as sealing and painting, can further reduce the risk of chemical exposure.
Pressure Treated Wood Brands, Costs, and Availability
Popular pressure treated lumber brands
Various brands produce pressure treated lumber, each with its unique treatment process and chemical formula. Some popular pressure treated lumber brands include:
- YellaWood
- ProWood
- NatureWood
- MicroPro Sienna
- Preserve
When choosing a pressure treated wood brand, consider factors such as the type of treatment, environmental certifications, and performance characteristics.
Pressure treated wood prices
Pressure treated wood prices vary depending on factors like the type of treatment, wood species, dimensions, and the retailer. Here, we provide a general comparison of prices from two popular home improvement stores.
Home Depot pressure-treated lumber prices
At Home Depot, pressure treated lumber prices can range from:
- $2.50 to $5.50 for 2x4s (8 feet long)
- $7.00 to $12.00 for 2x6s (8 feet long)
- $10.00 to $20.00 for 4x4s (8 feet long)
Remember that prices can vary depending on your location and the specific type of treated wood you need.
At Lowe’s, pressure treated lumber prices can range from:
- $2.75 to $6.00 for 2x4s (8 feet long)
- $7.50 to $13.00 for 2x6s (8 feet long)
- $11.00 to $22.00 for 4x4s (8 feet long)
Again, prices may vary depending on your location and the specific type of treated wood you need.
Several factors can affect the price of pressure treated lumber:
Type of treatment: Different treatments have varying costs, which can impact the overall price of the wood.
Wood species: Some wood species are more expensive than others, affecting the price of pressure treated lumber made from them.
Dimensions: The size and length of the lumber will impact its price, with larger and longer pieces generally costing more.
Market conditions: The price of lumber can fluctuate based on supply and demand and other market conditions.
When should I buy pressure treated wood
The best time to buy pressure treated wood depends on your project timeline and budget. Lumber prices fluctuate throughout the year, so monitoring market trends and planning is essential.
Additionally, consider factors like weather conditions, project deadlines, and seasonal sales when determining the best time to buy pressure treated wood for your project.
Identifying Pressure Treated Wood and Choosing the Right Type
How to tell if wood is pressure treated
Determining whether wood is pressure treated can be challenging. Here are some tips to help you identify pressure treated wood:
Color: Pressure treated wood often has a greenish tint due to the treatment chemicals. However, some types may have a brown or dark honey color.
Surface texture: The surface of pressure-treated wood can have small slits or indentations resulting from the treatment process.
End tags or stamps: Many pressure treated wood products have tags or stamps on their ends that indicate the treatment type, wood grade, and other specifications.
Smell: Pressure treated wood can have a distinct chemical odor, especially when it’s new.
Different grades of pressure treated wood
Pressure treated wood comes in various grades, each suitable for different purposes:
Select grade: This grade has minimal knots, making it ideal for applications requiring a smooth and uniform appearance.
Standard grade: This grade is suitable for most general construction applications, with a moderate number of knots and defects.
Utility grade: This grade has more knots and defects, making it suitable for applications where appearance is not a priority.
What is the best treated lumber for ground contact
When choosing treated lumber for ground contact, selecting a wood with an appropriate preservative retention level is essential.
The American Wood Protection Association (AWPA) has established specific standards for ground-contact wood:
UC4A (General Use): Suitable for most ground contact applications, such as deck supports and fence posts.
UC4B (Heavy Duty): Recommended for wood used in critical structural applications or environments with high decay hazards.
UC4C (Extreme Duty): Ideal for wood subjected to extreme decay hazards, such as freshwater or saltwater exposure.
Two basic types of pressure treated lumber
Above Ground (UC3) and Ground Contact (UC4). Above ground-treated lumber is suitable for applications with minimal ground contact or moisture exposure.
Ground Contact treated lumber is designed for direct contact with the ground or when exposed to high moisture levels.
Wood Types Used for Pressure Treatment
Spruce and pine are the most commonly used softwoods for pressure treatment, sourced from sustainably managed forests. A new one is planted for every tree harvested to prevent total deforestation.
These fast-growing woods are unsuitable for outdoor use and are not sustainable if left untreated. Chemical preservation (impregnation) extends the wood’s lifespan from five to fifteen years.
Pressure Treated Wood Myths and Misconceptions
Can pressure treated wood be burned
Burning pressure treated wood is hazardous due to releasing toxic chemicals, such as dioxins and furans. These chemicals can cause respiratory issues and other health problems. Instead, responsibly dispose of pressure-treated wood by taking it to a landfill or recycling facility.
Arsenic usage in pressure-treated wood
Chromated copper arsenate (CCA) was a widely used wood preservative that contained arsenic. However, concerns about potential health risks led to a voluntary industry phase-out of CCA for residential uses in 2003. Nowadays, most pressure treated wood uses alternative preservatives, such as alkaline copper quaternary (ACQ) or copper azole (CA), which do not contain arsenic.
Is pressure treated wood safe for gardens
Using pressure-treated wood in gardens is a controversial topic. While modern pressure-treated wood uses safer preservatives, there is still a risk of chemicals leaching into the soil.
To minimize this risk, use a plastic or fabric barrier between the wood and soil or choose naturally rot-resistant wood species, such as cedar or redwood.
Sealing pressure-treated wood for indoor use
Sealing pressure-treated wood with a high-quality sealer or paint can minimize the risk of chemical exposure when used indoors.
However, it’s still best to avoid using pressure-treated wood for indoor applications where direct contact or prolonged exposure is likely, such as furniture, countertops, or children’s play areas.
Instead, consider using untreated wood or other non-toxic materials for indoor projects.
Weighing the pros and cons of pressure-treated wood
Pressure-treated wood offers numerous advantages, including increased durability, resistance to decay, and cost-effectiveness. However, there are also potential risks, such as chemical exposure and environmental concerns.
When deciding whether to use pressure-treated wood, consider the specific application, the availability of alternative materials, and the potential health and environmental impacts.
To make an informed decision about using pressure-treated wood, consider the following factors:
Purpose: Determine whether the wood will be exposed to moisture, insects, or ground contact. Choose the appropriate grade and type of pressure-treated wood for your needs.
Safety: Consider the potential risks of using pressure-treated wood, particularly in indoor or sensitive applications. Take precautions to minimize exposure to chemicals and follow proper handling guidelines.
Alternatives: Explore other options, such as naturally rot-resistant wood species or composite materials, which may offer similar benefits without the potential risks associated with pressure-treated wood.
Defects found in pressure-treated wood
Sometimes, a customer finds flaws in the process without understanding much of it, as in the review above. Some of the following defects were found:
Formation of salts
With pressure-treated wood, salts sometimes appear on the wood surface; this resin turns yellow/green due to impregnation. These spots are gradually disappearing.
Suppose there are green spots on the wood; there’s nothing you can do about this: Remember that this is quite normal.
Mold and Mildew
Wood impregnated by boiler pressure induction becomes very damp during treatment. As a result, the wood can be susceptible to mildew or mold, especially during warmer seasons.
These external imperfections on the product disappear independently but are also easy to remove manually.
Since wood can expand and contract because it is a natural product, the dimensions stated in the catalog and product pages on the internet may show slight deviations.
How to care for Mildew and the formation of salt crystals
All mold, stains, salts, etc., can be washed off or left on; eventually, they disappear. It is a standard feature of wood that has been pressure-treated.
“Don’t scrub off the splatter!” it will remove the protection. You can safely remove resin drops with a sharp knife, but do not scrub the surface.
As we know, these are not spattered, but they are intrinsic properties of wood and are a normal result of the impregnation process, in which the copper component reacts with the moisture and sap in the wood itself.
Slight fading after the pressure-treated process
Sunlight influences wood, and little can be done about it; During storage, some areas may be covered due to packaging, positioning, etc.
Other areas may be exposed to light. Light triggers a reaction in the wood, turning it brown and silvery. Again: nothing you can do about it, and you better consider it.
Paint or stain pressure-treated wood
Staining pressure-treated wood seems a bit doubly like. Wood that has been impregnated has already been treated. Impregnation ensures that the wood lasts longer.
Why would you still stain pressure-treated wood? Due to the impregnation process, the wood is protected against influences, so additional treatment is unnecessary for principle.
This wood will last 10 to 15 years, thanks to the impregnation. Please note that this wood is not protected against every external factor.
Discoloration may occur under the influence of weather and light. To prevent this, you can treat the wood with special oils.
How can you stain pressure-treated wood?
Fortunately, staining pressure-treated wood is not too difficult a task. Start preparing the substrate. Remove green mold if present.
A solution of water and soda is sufficient, but special products are also available.
Then clean the entire surface and make sure that you degrease the surface. If necessary, you can use a high-pressure cleaner to clean the wood, for example, to (re)stain your fence.
After the wood surface has been thoroughly cleaned, it is recommended to let it dry and then sand it well. After sanding, it’s a good idea to dust the wood to remove all the dust.
If there is soil around the fence you do not want to pollute, it is recommended to cover the ground beforehand. Now you can get started with the stain. It is up to you which stain you choose.
White stain pressure-treated wood and black stain pressure-treated wood are options. You choose what to do with this surface. Using a roller or block brush is best if you paint large surfaces. Use a flat brush for smaller surfaces.
Final thoughts
Understanding pressure treated wood is crucial for anyone working with wood, whether you’re a professional woodworker or a DIY enthusiast.
By learning about the various types, treatment chemicals, and safety precautions, you can decide on the most suitable materials for your projects.
By considering the pros and cons of pressure treated wood and evaluating alternative materials, you can create lasting, safe, sustainable structures and creations.