While pressure-treated wood is designed to withstand external elements, burying it in the ground presents unique challenges. The general consensus among experts is that it is not recommended to bury pressure-treated wood directly in the ground, primarily if it comes into contact with soil or water consistently. The primary reasons include:
- Leaching of Chemicals: Pressure-treated wood is treated with chemicals such as copper-based compounds, including copper azole or alkaline copper quaternary (ACQ). When the wood is in contact with soil or water, these chemicals can leach out, potentially contaminating the environment and groundwater.
- Accelerated Decay: Although pressure-treated wood is resistant to decay, prolonged exposure to soil or water can accelerate the breakdown of the wood fibers, reducing its lifespan.
- Limited Effectiveness: When pressure-treated wood is buried in the ground, the preservatives present in the outer layers may not effectively penetrate the core, leaving the untreated wood vulnerable to decay and insect infestation.
Alternatives to Burying Pressure-Treated Wood
If you require wood to be buried in the ground for a project, several alternatives can be considered:
- Using barrier materials: To minimize contact between pressure-treated wood and soil, use a barrier material like plastic sheeting, pond liner, or geotextiles to line the hole before placing the wood. This can help reduce leaching and prolong the lifespan of the wood.
- Elevating the wood: Instead of burying the wood directly in the ground, consider elevating it using concrete piers, blocks, or other elevated structures to reduce contact with soil and moisture.
- Utilizing alternative materials: In cases where the wood will be in direct and continuous contact with soil or water, consider using alternative materials specifically designed for such applications, such as concrete, concrete blocks, or plastic lumber.
While pressure-treated wood offers many benefits in terms of durability and resistance to rot, burying it in the ground is not recommended. Leaching of chemicals, accelerated decay, and limited effectiveness are significant concerns when it comes to using pressure-treated wood underground. However, with the use of barrier materials or alternative materials, you can still achieve a long-lasting and reliable solution for your outdoor projects.