Is Straightening Warped Pressure Treated Wood Possible?

Pressure-treated wood that becomes warped is every carpenter’s nightmare. Warped wood can mess up measurements and ruin the wooden structure you build. So, is straightening warped pressure-treated wood possible, or does it go to waste?

Straightening warped pressure treated wood is possible through the heat and moisture technique. Applying pressure on wood or placing it in sunlight can also work. Another solution is to use a jack plane, which may reduce the material’s size. You can even get rid of the warpage at home.

Wood warping manifests itself in many ways. It usually happens when the wet wood doesn’t dry evenly or you don’t store it properly. This article will explain how to straighten wood warping and why the phenomenon happens in the first place. 

Is Straightening Warped Pressure Treated Wood Possible?

How To Straighten Warped-Pressure Treated Wood?

Straightening warped-pressure-treated wood is possible, but you must be careful with it. Excessive pressure or a poor drying technique can cause further damage. You can use several unwarping methods. You can even execute most of these techniques at home without professional help. 

Let’s look at some of them.

The Sunlight Technique 

With this technique, you use sunlight to straighten warped wood. The sunlight technique takes some time to give you results, so you mustn’t use it for time-sensitive jobs. Here’s what you’ll need for this method.

  • Towels
  • Water bucket.
  • Flat, water-resistant table or any flat surface.

Here are the steps you’ll want to follow:

  1. Soak the towels thoroughly in the water bucket. 
  2. Take the towels out and wring them until all the water is out. Your towels must be damp, not soaking wet. 
  3. The next step is to wrap the wood in damp towels completely. 
  4. You must place the wood on a flat, water-resistant surface or table. It’s important to ensure that the warped side of the wood faces downward. It shouldn’t face the sunlight.
  5. Leave the table out in the sunlight until the wood is completely dry. 

Remember to find an area that receives direct sunlight for extended periods. The table or the surface must receive light evenly from all sides. 

You must repeat the sunlight technique until you successfully unwarp the wood. It can take you several days to achieve the desired results. 

The Heat and Moisture Technique 

You can use the heat and moisture technique at home. It doesn’t cost any money or require too much effort. Here’s what you need for the heat and moisture technique:

  • Towels.
  • Water bucket.
  • Iron. 
  • Flat surface or table.

Let’s see the method now:

  1. You must first soak the towels in the water bucket thoroughly.
  2. Wring the towels so that there is no dripping water. You need damp towels, so you must wring them well. 
  3. Next, you must wrap the wood properly with damp towels. 
  4. Plug the iron in, set the temperature to the highest limit, and wait for it to heat up. It’s best to get a steam iron as it works best for this method.  
  5. Now place the wood on the flat surface or table with the warp side facing upward. 
  6. The next step is the ironing of the wood. You must place the iron on the warped surface and leave it there for a few seconds (about 10 seconds).
  7. Slide the iron onto the next warped area. 
  8. Check for the results by running your hand along the length of the wood.
  9. Leave the wood out to dry if the warped surface is smooth. 

Once you iron all the surfaces and check for results, it’s best not to remove the towels. You may have to repeat the ironing process several times to achieve the desired effect. 

Remember that the heat and moisture technique works best for thinner wood panels. You won’t get any results if the wood is thick or the warping is severe. 

The Pressure Technique 

The pressure technique is also an excellent way to smooth the warped surface of the wood. However, you may have to invest a little money in it, especially if you don’t have clamps to hold the wood down. 

Here’s what you need for the pressure technique:

  • Towels.
  • Water bucket.
  • Cling sheet.
  • Clamps.
  • Flat surface or table. 

Let’s see the method now:

  1. The first step is to soak the towels in water thoroughly. 
  2. Next, wring the towels out to make them damp. The water shouldn’t drip. 
  3. Now, cover the wood with towels completely.
  4. You must wrap the wood with the cling sheet to prevent moisture from escaping. You must make the cling sheet airtight.
  5. Now place the wood on the table right on one of the edges.
  6. Now put the clamps on so the wood clamps tightly to the table. 
  7. Leave the clamps on for several days. 

There is another way to use the pressure technique. 

The process is the same up until you wrap the wood with plastic. However, once the wood is damp, you can remove the wrapping and place the wood on the table. Now, you can clamp the wood down to the table and leave it for several days to remove the warpage. After clamping the wood, you must apply heat to the warped area. 

Check for results after a week. You may have to rewrap the wood if the issue is still there. This method may take a while as you must apply the pressure and then leave the clamps on until the warped surface becomes smooth. 

The Nylon Paper Technique 

The nylon paper technique is easy and doesn’t take too much time. Here’s what you’ll need for this method:

  • Towels.
  • A water bucket.
  • Nylon paper. 
  • Bricks or some other objects with similar weight. 
  • A flat surface or a table. 

Let’s see the method:

  1. The first step is to soak the towels thoroughly in the water bucket. 
  2. Wring the towels so that no water is dripping from them.
  3. Wrap the wood in damp towels.
  4. Next, wrap the wood with nylon paper. 
  5. Now, place the wood on the table or a flat surface with the warpage facing upward.
  6. The next step is to place the weight or bricks on the warped area. 
  7. Leave the weight on the board so it can flatten the warpage. 

The method may take between two to seven days to work. 

Is Straightening Warped Pressure Treated Wood Possible?

Reasons for Wood Warping

Warped wood doesn’t always mean the material is of bad quality. It sometimes happens when you don’t store the wood in optimal conditions or you don’t take care of it. 

Let’s understand some of the reasons why pressure-treated wood can warp.

Exposure to Too Much Moisture

You need moisture to unwarp the wood, but moisture can also be the reason for warping. When you leave the wood in the rain, or it gets wet another way, it can lead to warping. The reason is simple. 

Some parts can swell up when the wood stays wet for a long time. When the same wood dries unevenly, it can’t return to its original shape. So, its surface warps in different places. 

Extreme Temperatures

Wood can warp when you leave it in the sun for an extended period. Prolonged exposure to heat or sunlight can cause thermal expansion. When the wood expands, the space between the particles can warp. 

As the temperature drops, the wood tends to shrink. The shrinking changes the wood’s shape unevenly, leading to warping. So, it’s important to store wood in moderate temperatures.

When You Store Wood Incorrectly

Proper wood storage is essential. It means the conditions of your warehouse must be suitable for the material. The storage area shouldn’t be too hot, wet, or humid. It must also protect the wood from external factors such as rain. 

Humidity can also lead to excessive moisture absorption. So, constant heat and humidity can change the shape of the wood, causing it to warp. 

Another factor to consider is how you place the wood. It needs proper support along its length to maintain its shape. The wood will warp if you leave it standing upright. 

Another important element is to dry the wood thoroughly before you store it. Wet pressure-treated wood will warp even if it is lying flat on a surface. This happens due to uneven drying in storage rooms with poor ventilation or high humidity. [Why Does Your Pressure Treated Wood Feel Wet?]

The right way to keep wood is to store it in an area with moderate temperatures and dry conditions with shade. If you live in a humid region, you must wrap the wood in a material that doesn’t let moisture in.

Types of Warping

Warping occurs when wood bends or twists out of shape, making the surface bumpy and uneven. Warping is most common in poor-quality wood. However, sometimes, even quality wood can warp due to bad storage conditions. 

Wood can warp in more than one way.

The types of warping include:

  • When the wood bends backward or inwards, the warping is called Bow.
  • When the wood turns at the edges at an angle of 45 degrees, the warp is called Kink.
  • An inward bend at the edges along the length of the wood is called a Cup warp.
  • Sometimes the edges of the wood can twist out of shape leading to a Twist warp.
  • When the lumber curves inward from one edge, forming a C-type shape, the warp is called Crooked.  


Pressure-treated wood can warp due to several reasons. However, the good news is you can unwarp it by using several techniques. Most of these methods aren’t that difficult to execute. However, most DIY techniques take a bit of time to work.

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