Sealing Around PVC Pipe Through Concrete (A How-To Guide)

There are many ways you can seal around PVC pipes. You can use epoxy, fiberglass resin tape, silicone, and rubber tape. It’s a pretty easy process. But what about PVC pipes that are passing through concrete?

The fact that these pipes are covered makes it more difficult to access them. The good news, however, is that there are several ways you can seal around PVC pipes through concrete.

I will share these methods with you in this article and a few tips you can follow.

PVC pipe passing through concrete wall

How to Seal Around PVC Pipe through Concrete?

Here are the top recommended methods for sealing around PVC pipes through concrete;

1. Use Hydraulic Cement

If you don’t know what hydraulic cement is, this is a product that was specifically formulated to stop water leaks in masonry structures. It looks like mortar, however, it usually dries very fast after it has been applied.

What I like most about hydraulic cement is that it works even in the presence of water. So, if your PVC pipes are currently leaking, you can go ahead and seal them with hydraulic cement.

Sealing around PVC pipe through concrete with hydraulic cement guarantees long-lasting repairs. It’s not an expensive product and the best part is that you can get it at a nearby hardware store.

Hydraulic cement is equally as effective in vertical applications. And as it dries, it expands a little bit. Over time, hydraulic cement will not shrink and neither will it corrode.

If you are looking for a quick and effective method of sealing PVC pipes through concrete masonry, hydraulic cement should be your top pick.

2. Fill It with Polyurethane and Silicone Sealants

The other products you can use to seal around PVC pipes through concrete are polyurethane and silicone sealants. Polyurethane sealants are well-known for creating tight seals. It’s waterproof and can stop leaks in hard-to-reach areas.

Its counterpart, silicone is an equally effective sealant. It’s also waterproof and can withstand long-term exposure to concrete.

Can I Use Expanding Foam to Seal Around PVC Pipes through Concrete?

Absolutely not. I understand why spray foam may seem like an excellent option for this application. However, if your PVC pipes are leaking, expanding foam will not adhere properly to the concrete and it may end up being ineffective.

Expanding foam is undeniably an incredible DIY product. But it shouldn’t be used to seal around PVC pipes, especially those that are running through concrete.

It’s also worth mentioning that in some areas, using spray foam to seal PVC pipes inside concrete is against local codes. To avoid issues with the inspectors, you should refrain from using expanding foam.

Do You Need to Dig Through Concrete to Seal Around PVC Pipes?

If you are interested in manually sealing PVC pipes, there is no other option but to dig through the concrete. But you do not need to go through all this hard work.

If a pipe is going through a concrete floor or wall, digging till you expose it can take forever. With a product such as hydraulic cement, all you have to do is fill it inside the hole and the leaking should stop immediately after it dries.

Does the Concrete Need to Be Cleaned Before Sealing Around PVC Pipes?

That’s pretty obvious. The cleaner the surrounding concrete is, the stronger the adhesion of the sealant will be. In concrete masonries that are pretty old, take your time to clean the outside and entry points.

If you can close the supply line so that the pipe can stop leaking that would be better because the concrete will dry up.

Should You Hire a Professional Construction Company to Seal PVC Pipes through Concrete?

There is absolutely nothing wrong with hiring professional help, especially if this is a project that you are not familiar with. An expert contractor will evaluate the situation and recommend a suitable approach.

They will most likely fill the concrete with a polyurethane sealant or use hydraulic cement. One of the perks of working with such a company is that you are guaranteed that the leak will stop.

Also, you won’t have to guess how to fix this problem. It will cost you a few bucks, but when your PVC pipe stops leaking through concrete, you will be glad you called in the experts.

Can You Seal Around PVC Pipes with Fresh Concrete?

This is a pretty interesting idea. But you have to understand that concrete is a porous material. Yes, you can fill the areas around the PVC pipe with more concrete but if there is a leak, water will still seep through and you would have delayed the inevitable.

What Makes Sealing Around PVC Pipes through Concrete Difficult?

The best way to seal a PVC pipe is if you have direct contact with it. The reason sealing around PVC pipes through concrete is so difficult is that you are working from outside.

The inaccessibility of the pipes makes it challenging for you to create a tight seal. This challenge is what limits the number of ways you can seal around PVC pipes.

Even though it’s a difficult procedure, it’s still doable. If you follow the tips, I have shared with you, it will be much easier to seal the PVC pipes and stop the leaks for good.

Can You Inject a Sealant into Concrete to Seal Around PVC Pipes?

This is a pretty invasive procedure and it’s also quite costly. It is possible to inject a sealant into the concrete and seal leaking PVC pipes. But you will have to first confirm the location of the leak.

As mentioned earlier, concrete is porous. If there is a leak in a pipe that’s passing through concrete, depending on the water flow, the water can come out of anywhere.

If you are not sure where the leak is located, you may end up wasting a lot amount of sealant and not fixing the problem. This is a method that should only be executed by professional contractors.

Should You Seal PVC Pipes Before or After Pouring Concrete Over Them?

To avoid all the trouble associated with sealing PVC pipes after pouring concrete, it’s best to do it before. You can wrap it with silicone tape and then pour concrete over it.

Other special types of tape are concrete-friendly. With a little bit of research, you should be able to identify quality tapes for this project.

Why Should You Seal PVC Pipes that Are Running Through Concrete?

One of the main reasons people seal PVC pipes running through concrete is to fix leaks. When PVC pipes entered the market a few years ago, it was received with much enthusiasm because of its durability. However, it is also susceptible to leaks. Sealing closes any holes that may have developed along PVC pipes.

Even though concrete is water resistant, water leaks can damage nearby materials. Such leaks can also lead to abnormal water bills. Sealing is an excellent method of dealing with these leaks.

Still, in dealing with leaks, I must mention that encasing pipes in concrete is a pretty standard procedure. PVC pipes can last for years under concrete. The concrete is responsible for protecting the pipes from structural movements and damage.

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