PVC pipes are commonly used in residential and commercial buildings for plumbing. In many cases, these pipes need to be laid outdoors. And there lies the risk of these pipes breaking or corroding over time. So, what’s the right way to seal these pipes?
Can PVC pipe be buried in concrete? Yes, you can bury PVC pipes in concrete. But that should be done in the right way where the PVC pipe isn’t in direct contact with the concrete. Otherwise, the concrete can create extreme pressure on the pipe and break it.
Let’s know more about this topic throughout the article.
Can PVC Pipe Be Buried In Concrete?
Be it water supply lines or wastewater lines, PVC pipes are everywhere. They are commonly used in almost all plumbing systems for their reliability. But when you need to route them through the ground, you are at risk of having eroded pipes after a few years.
Different elements in the soil can affect the longevity of these pipes. So, the best way to protect them is to cover them with concrete. In some cases, sewer pipe encased in concrete might be a lot less harmful to the environment even if it has got some minor leaks.
Now that you know PVC pipes can be buried in concrete, how should you do that? And what should you keep in mind while doing this? Let us guide you throughout the process.
How to Bury PVC Pipe In Concrete?
Before pouring concrete around plumbing, you should make sure everything is done properly. Follow these steps below to seal PVC pipes in concrete.
1. Dig a Trench to Lay the Pipe
Laying the plumbing on the ground isn’t safe. So, you need to dig a narrow and shallow trench for this. You should make sure the PVC pipe doesn’t come in direct contact with the concrete. So, fill the bottom of the trench with sand or gravel. It also helps soak any fluid should the pipe has any leaks.
2. Make Sure the Pipe Has No Leaks
Before laying the pipe, give it a visual inspection and make sure there is no leak on the pipe. If there is any leak on the pipe, it may increase once buried in concrete.
3. Cover the Pipe with Sand or Gravel
Once the pipe is laid, you need to cover its top with sand or gravel in the same fashion you did at the bottom. This will prevent the concrete from creating extra pressure on the pipe.
4. Prepare the Concrete Mixture
While preparing the concrete mixture, use all the ingredients in the correct ratio. If the concrete is too dry or too wet, it can be harmful to the plumbing system.
5. Pour the Concrete Mixture Over the Pipe
Once the concrete mixture is ready, carefully pour the concrete over the sand or gravel layer. Let the concrete sit and cure for at least 24 hours. Remember, the thickness of the concrete layer over the pipe should never be higher than six inches.
How Deep Should PVC Pipe Be Under Concrete?
As we have already mentioned, the maximum thickness of concrete over PVC pipe should be six inches. Anything thicker than that might cause problems when you put plastic water pipe in concrete.
If you use rigid PVC pipes, thicker concrete layers might make the pipe brittle. As a result, leaks would develop over time. And if you use flexible PVC pipes under thick concrete, the weight of the concrete layer might suppress the pipe and block the plumbing system.
So, you should carefully pour the concrete layer so that it doesn’t cross its allowed thickness.
Related Read: How Repair Damaged Plastic Pipe Threads?
Does Cement Hurt PVC Pipe?
The chance of cement hurting PVC in slab is very low. There might be no chemical effect of cement on PVC pipes. But if the PVC pipe is directly inside the concrete encasement, it might not have enough space for expansion or contraction. As a result, the pipe can break over time.
And if there are major shifts or cracks in the concrete layer surrounding the PVC pipe, it can physically hurt and damage the pipe. So, you should be careful when layering concrete around PVC pipes.
How Long Will PVC Pipe Last Under Concrete?
PVC pipes usually have a long lifespan. In general use, they can survive for about 40-60 years. But when you install drain pipe under concrete, their lifespan gets extended.
As the pipe is not exposed to direct sunlight when under concrete, it will last for about 50-100 years. The concrete layer around PVC pipes also protects them from harmful elements in the soil. It is one of the reasons why PVC pipes last longer under concrete than in the ground.
But if PVC pipe isn’t properly buried under concrete, its lifespan may get reduced.
Read more: Why is my kitchen sink drain pipe leaking?
To conclude this discussion, we want to remind you of the importance of burying PVC pipe under concrete in the right way. You must leave some flexible space around the pipe so that it can flex. Otherwise, the chance of PVC pipes breaking under concrete is too high.
The sand or gravel layer you use around the pipe works as the flexible layer and protects the pipe from direct hits by the concrete layer.
As a result, the plumbing system will be more durable than just pouring concrete over the PVC pipe. We hope you do things the way we showed and save your plumbing system from damage.