Preservation of Timber And Methods For Preservation in Civil Engineering | Types of Preservatives

Types of Preservatives in Timber

The Following Preservatives Are Commonly Used for Preservation of Timber:

  1. AsCu treatment
  2. Chemical Salts
  3. Coal Tar
  4. Creosote Oil
  5. Oil Paints
  6. Solignum Paints

1. AsCu Treatment:

  • AsCu treatment involves the use of copper and arsenic compounds to protect timber from insects, fungi, and decay.
  • The treatment involves impregnating timber with a solution of copper and arsenic salts under pressure.
  • AsCu treatment is widely used because it is cost-effective and provides long-lasting protection.

2. Chemical Salts:

  • Chemical salts, such as borate and ammonium sulfate, are commonly used to protect timber from insects and fungi.
  • The salts are dissolved in water and then injected into the timber under pressure.
  • Chemical salt treatment is effective in preventing insect infestation and decay but may not provide protection against weathering.

3. Coal Tar:

  • Coal tar is a by-product of coal processing, and it is commonly used as a timber preservative.
  • Coal tar is applied to the timber surface and penetrates into the wood fibers.
  • Coal tar provides protection against insects, fungi, and weathering but may discolor the timber.

4. Creosote Oil:

  • Creosote oil is a mixture of chemicals obtained by distilling coal tar.
  • It is commonly used to protect timber from insect infestation and decay.
  • Creosote oil is applied to the timber surface, and it penetrates into the wood fibers.
  • It provides long-lasting protection against insects, fungi, and weathering.

5. Oil Paints:

  • Oil paints are commonly used to protect timber from weathering and water damage.
  • The paint forms a barrier on the timber surface, preventing water from penetrating the wood.
  • Oil paints may also provide some protection against insects and fungi.

6. Solignum Paints:

  • Solignum paints are oil-based paints that contain fungicides and insecticides.
  • These paints are used to protect timber from insect infestation and decay.
  • Solignum paints penetrate into the wood fibers, providing long-lasting protection.

Conclusion: In conclusion, timber preservatives are essential to protect timber from insect infestation, decay, and weathering. There are various types of timber preservatives, including AsCu treatment, chemical salts, coal tar, creosote oil, oil paints, and Solignum paints. The choice of preservative depends on the type of timber, the intended use, and the environment in which the timber will be used. By choosing the right preservative, you can ensure that your timber lasts longer and remains in good condition.

Methods For Preservation Of Timber:

Following are the six methods adopted for preservation of timber:

  1. Brushing
  2. Charring
  3. Dipping
  4. Hot and Cold Open Tank Treatment
  5. Injecting Under Pressure
  6. Spraying.

1. Brushing:

Brushing on timber

  • Brushing involves applying a preservative solution to the timber surface using a brush.
  • The preservative solution penetrates into the wood fibers, providing protection against decay and insect infestation.
  • Brushing is a simple and cost-effective method of timber preservation. However, it may not provide long-lasting protection.

2. Charring:

Charring on timber

  • Charring is a traditional method of timber preservation that involves burning the timber surface to create a layer of charcoal.
  • The charcoal layer provides protection against decay and insect infestation.
  • Charring is a low-cost preservation method that can be used for small-scale projects. However, it may not be suitable for large-scale projects.

3. Dipping and Steeping:

  • Dipping involves immersing the timber in a preservative solution for a specified period.
  • The preservative solution penetrates into the wood fibers, providing protection against decay and insect infestation.
  • Dipping is a simple and effective preservation method. However, it may not be suitable for large-scale projects due to the large volumes of preservative solution required.

4. Hot and Cold Open Tank Treatment:

  • Hot and cold open tank treatment involves immersing the timber in a tank containing a preservative solution.
  • The tank is heated to a high temperature for hot treatment or maintained at room temperature for cold treatment.
  • The preservative solution penetrates into the wood fibers, providing protection against decay and insect infestation.
  • Hot and cold open tank treatment is an effective preservation method. However, it may require a significant investment in equipment and infrastructure.

5. Injecting Under Pressure:

  • Injecting under pressure involves injecting a preservative solution into the timber under high pressure.
  • The pressure forces the preservative solution deep into the wood fibers, providing long-lasting protection against decay and insect infestation.
  • Injecting under pressure is a popular preservation method for large-scale projects. However, it requires specialized equipment and skilled personnel.

6. Spraying:

Spraying on timber

  • Spraying involves applying a preservative solution to the timber surface using a sprayer.
  • The preservative solution penetrates into the wood fibers, providing protection against decay and insect infestation.
  • Spraying is a simple and effective preservation method that can be used for small-scale projects. However, it may not provide long-lasting protection.

Conclusion: In conclusion, timber preservation is essential to ensure the long-term use of timber in civil engineering projects. There are various preservation methods, including brushing, charring, dipping, hot and cold open tank treatment, injecting under pressure, and spraying. The choice of preservation method depends on the type of timber, the intended use, and the environment in which the timber will be used. By choosing the right preservation method, you can ensure that your timber lasts longer and remains in good condition.

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