What is Wolmanized Lumber? (All You Need to Know)

Wolmanized lumber is a type of treated wood, often used for exterior applications, but sometimes found inside residential properties.

Wolmanized lumber is wood that has been through a special treatment process using CCA (Chromated Copper Arsenate). This gives it protection against termites, fungal decay, and rot.

The process is named after Dr. Karl Heinrich Wolman, who created the process in Germany back in 1911. Since then, it has been used to treat wood for a number of applications. But is it safe and are there alternatives? Read on to learn more about Wolmanized lumber.

How Does Lumber Become Wolmanized?

First, the lumber must go through a steaming process to open up the wood cells before being placed in a vacuum chamber. The CCA treatment is then introduced as a liquid solution. This solution is forced into the wood cells by the pressure created by the vacuum. The chemical reaction that takes place forms what’s known as a copper-chromium-arsenic complex which creates an effective pest barrier around the treated lumber and makes it an unattractive food source for insects. It also increases the strength of the wood, but the appearance remains the same.

What is Chromated Copper Arsenate (CCA)?

Chromated Copper Arsenate (CCA) is a chemical compound used in wood to protect against termites, fungi, and other pests. It is made up of oxides from chromium, copper, and arsenic, which is what puts pests off.

When the Chromated Copper Arsenate is introduced to the wood, the compounds become ‘fixated’ meaning that they are completely insoluble and are bound to the wood.

People are often concerned about the presence of arsenic because they know it to be a poison. However, it is completely naturally occurring and it becomes fully bound to the wood, so it does not leach out.

Is Wolmanized Wood Safe?

There have been concerns about the safety of wolmanized wood in the past. However, when used in the right way, it is safe.

Wolmanized lumber is designed for use outside as the treatment protects it against outdoor elements. So, any potential for leaching or off-gassing should not be a concern. But tests show that even when used indoors, wolmanized wood should not pose a risk to your health. As long as the process has been carried out properly, the CCA will be fixed into the cells of the wood and will not escape.

That said, new options have still been developed in recent years and these are often used in place of wolmanized lumber for residential purposes.

Can You Still Buy Wolmanized Lumber Today?

In the last 20 years, there have been concerns about the arsenic in wolmanized lumber and this led to the introduction of different pressure-treated wood compounds. By 2003, the use of lumber containing CCA was banned for residential structures.

A lot of wood is treated with Micronized Copper Azole (MCA) or other benign alternatives instead. The copper and the ‘azoles’ in this compound give the same protection against decay and termites. The most notable difference is that it does not contain arsenic.

Lumber can also be pressure treated with alkaline copper quaternary (ACQ), which is a compound containing copper and ammonium.

However, even though Wolmanized lumber is banned for residential purposes like homes, playgrounds, picnic tables, landscaping features, etc. it can still be bought and used for other applications. It remains popular because it is relatively cheap and durable.

What is Wolmanized Wood Used For?

Wolmanized lumber is usually used in situations where the wood will come into contact with a lot of moisture, or if termites are a significant problem. It has a lot of uses in an agricultural setting for fences and posts, etc.

Agricultural fence

Common applications include:

  • Lumber for marine construction
  • Pilings
  • Poles
  • Highway construction
  • Agricultural fence posts
  • Cooling towers
  • Shakes and shingles

How Long Does Wolmanized Wood Last?

With the right treatment, Wolmanized wood can last for more than 25 years. If it is properly maintained and cared for, it should not succumb to rot or be eaten by termites. However, is it is often used for applications where it is exposed to harsh conditions, and this can shorten its lifespan.

Wolmanized vs Pressure Treated Wood (Is There a Difference?

Wolmanized wood is a type of pressure treated wood. Specifically, wolmanized lumber refers to wood that has been pressure treated with CCA. There are other types of pressure treated wood that have been strengthed and protected with compounds like MCA or ACQ, but these do not count as Wolmanized lumber.

Can You Paint Wolmanized Lumber?

Yes, you can paint wolmanized lumber. But you should only paint it once it has fully dried. Bear in mind that wolmanized lumber takes much longer to dry (weeks or even months). If you put water on it and it still beads on the surface, it is not dry enough for painting yet.

Once the wood starts absorbing the water, it is ready to paint. It is best to use a latex-based primer first and then use an exterior water-based paint. Oil paints do not work well on wolmanized lumber so they are best avoided.

Can You Stain Wolmanized Lumber?

Staining wolmanized lumber is often better than painting as it is easier to apply. Again, it is crucial that you wait until the wood is fully dry before you stain it. Use an oil-based semitransparent exterior wood stain for best results.

Is Wolmanized Wood Bad for the Environment?

CCA-treated wood has been shown to leach chromium, copper, and arsenic into the soil. This suggests that it poses a problem for the environment. However, studies into the impact show that the migration of these compounds is very limited, meaning that they don’t spread around and cause damage to the surrounding environment.

How to Dispose of Wolmanized Lumber

Disposing of wolmanized lumber in the proper way is important as it can pose a risk to health and the environment.

The most important thing to remember is that wolmanized lumber should absolutely never be burned. In fact, this is illegal because it releases so many toxic fumes. There are a number of ways you can dispose of your wolmanized lumber safely:

Put it in the Regular Trash

In some cases, your local authority may accept wolmanized lumber. However, there will be specific pickup requirements, so check with them first before putting it in your bin.

Find an Eco-Friendly Landfill

There are some landfill facilities that are equipped to deal with wolmanized wood.

Take it to a Hazardous Waste Recycling Facility

CCA actually qualifies as hazardous waste, so a local recycling facility will manage it for you.

It is vital that you don’t simply throw your wolmanized lumber away and you ensure that it has been disposed of properly.

Wolmanized Lumber FAQs

How Long Does it Take the Green Color to Fade in Wolmanized Lumber?

On average, it takes a year for the green color to fade from wolmanized lumber. It will then have a natural gray tone to it. However, if you are unhappy with the green or the resulting grey that it fades to, you can stain it in whatever color you like.

What to do if You are Exposed to Wolmanized Lumber?

If you are exposed to wolmanized lumber, you should immediately wash and clean the area with soap and water, just in case. But you should be perfectly safe as long as the wolmanized lumber is still intact.

Is it Safe to Use Wolmanized Lumber for Seating?

Although the dangers of wolmanized lumber are not too serious, it is not legal for use in any residential setting. So, it is not recommended that you use wolmanized lumber for seating. There are many other alternative pressure treated wood options that are better.

When Did Wolmanized Lumber Begin?

Wolmanized lumber was first invented in 1911 in Germany. It has been used around the world since then. However, CCA was not developed until 1933. Shortly after this, it became the standard compound used to create wolmanized lumber.

Does HomeDepot Sell Wolmanized Lumber?

Yes, HomeDepot sells a range of pressure-treated lumber products both in-store and online.

Final Thoughts

Wolmanized wood has been a popular choice for many years and is still widely used today. However, there are a lot of concerns about the CCA that is used, particularly the presence of arsenic. It is for this reason that it was banned for residential purposes in 2003.

But it is still a very affordable and durable option for a lot of exterior projects, especially when there is a lot of moisture present. Many marine building applications, for example, use wolmanized lumber.

If you want to use this building material, it is important that you follow the right safety precautions and only use it in situations where it is safe. Make sure that you buy from a reputable supplier too, so the CCA is properly bonded to the lumber and there is no risk of off-gassing and leaching.

Ideally, you should contact a lumber expert for your next big construction project. They can advise you on whether wolmanized lumber is the right option for you or if other pressure treated woods are better. They can also ensure that wolmanized lumber is used safely in the right places. So, where wolmanized lumber is concerned, best leave it to the experts.

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