5 Tips to Keep in Mind When Burying uPVC Pipes Underground

5 Tips to Keep in Mind When Burying uPVC Pipes Underground

5 Tips to Keep in Mind When Burying uPVC Pipes Underground

Underground drainage systems are essential in any residential and commercial property that keep wastewater in check to prevent water damage. For such applications, the long-lasting and robust uPVC pipe has become the go-to choice for many projects for its unparalleled durability at an economical price.

That said, there are a couple of requirements for it to achieve its potential, starting with proper installation. Unlike other applications, burying uPVC pipes requires additional research before installation, like following relevant standards such as Land Transport Authority (LTA) and other local building codes. Below is a quick overview of how to take special care when handling underground uPVC to avoid damage and extend their lifespan.

1. Handling and Storage

While uPVC is a strong and rigid plastic with high weather resistance, that does not mean they are completely invulnerable to the elements. Like most other building materials, uPVC can expand and contract slightly under prolonged exposure to more intense weather conditions. Thus, it is vital to store and transport uPVC pipes correctly and understand how they move to control their expansion and contraction for the best fit and installation process.

2. Pre-installation

Before installing uPVC pipes underground, a quality check is a must to spot any signs of damage that may become problematic once buried. These defects include gouges, cuts, and split ends, which could compromise its structural integrity during operation.

If any are found, cut away the affected pieces and discard them. It is also recommended to use stakes and string to mark the location of the pipe prior to digging to secure the proper placement and help determine pipe length if necessary.

3. Trenching

For trenching, the best practices entail digging wide enough for installation with sufficient tolerances for expansion and contraction due to temperature changes. That said, avoid making them wider than is needed.

One of the best ways to make sure of this is by joining the pipes outside the trench before installing them. Also, ensure no large rocks are visible in the trench by removing or covering them with tamped earth to reduce the risk of pipe damage after burial.

4. Depth

It is crucial to determine the correct depth of the trench according to several factors, such as the uPVC pipe’s application, property location, and local weather. For instance, in regions with winter seasons, uPVC pipes should be buried 12 inches below the frost line at the very least to avoid ruptures under freezing temperatures.

On the other hand, if the location is expected to have heavy traffic, drainage trenches need to be 24-36 inches deeper. In cases with continuous heavy traffic, like beneath roadways, it may also be necessary to use concrete or metal. In short, adhere to the relevant standards and state and local building codes when calculating trench depth.

5. Backfill and Project Completion

Once the pipes are in place, it is best practice to wait out the solvent cement until it is fully cured and verify the stability of the entire pipeline. Also, inspect and test for leaks before backfilling, as any damages incurred during installation are easier to fix before the pipes are buried. Ensure that the first layer of backfill, which is generally around six to eight inches deep, must be free of any rocks or gravel larger than half an inch, while additional layers should be fine with having larger particles. Employ vibration or water flooding when tamping each layer for proper compaction.

Backfill and Project Completion


The durability, versatility, and ease of installation make uPVC one of the most popular piping materials for underground drainage systems and many other applications. By following the best practices around underground installation, uPVC pipes can better serve their purpose and be free of complications like leaks or flooding that can prove challenging to resolve once they are buried.

For the best and most eco-friendly uPVC piping solution for your projects, look no further than Vicplas’s wide range of lead-free pipes suited for various applications, from plumbing systems to hydroponic farming. We are dedicated to constantly innovating with piping systems for many industries offering unbeatable performance without compromising sustainability. We offer a large selection of underground pipes and fittings to suit any drainage project, including non-toxic SS213, SS272, and SS141 uPVC pipes ideal for commercial and domestic applications.

To learn more about our plumbing solutions and components for hydroponic systems in Singapore, contact us today for additional details.