DIY Concrete Conundrum: Is PEX Fitting Insertion Possible?

The answer is yes, you can embed PEX fittings in concrete, but it’s important to take the necessary precautions to ensure their longevity and performance. PEX, or cross-linked polyethylene, is a flexible and versatile plumbing material, and when properly installed, it can last for decades.

Considerations for Embedding PEX Fittings in Concrete

Before embedding PEX fittings in concrete, consider the following factors:

1. Type of Concrete: Not all types of concrete are suitable for embedding PEX fittings. High-strength concrete, such as that used in structural applications, can exert excessive pressure on the fittings, causing them to fail. Use a concrete mix designed for embedding plumbing fixtures.

2. Concrete Curing: Allow the concrete to cure for at least 28 days before subjecting it to water pressure. This will ensure that the concrete has reached its full strength and will not crack or shift, damaging the fittings.

3. Expansion and Contraction: PEX fittings can expand and contract with temperature changes. Ensure that there is sufficient space around the fittings to accommodate this movement without putting stress on the concrete.

4. Corrosion Protection: Concrete can be corrosive to metal fittings. Protect the fittings by using corrosion-resistant materials, such as brass or stainless steel.

Steps for Embedding PEX Fittings in Concrete

1. Plan the Layout: Determine the placement of the PEX fittings and mark their locations on the concrete surface.

2. Excavate the Holes: Dig holes in the concrete deep enough to accommodate the fittings and provide space for expansion.

3. Clean the Holes: Remove any loose concrete or debris from the holes to ensure a secure fit.

4. Apply Sealant: Apply a sealant to the holes to prevent water seepage around the fittings.

5. Insert the Fittings: Carefully insert the PEX fittings into the holes and ensure they are level and properly aligned.

6. Fill the Holes: Fill the holes around the fittings with concrete mix, using a trowel to smooth the surface.

7. Cure the Concrete: Allow the concrete to cure according to the manufacturer’s instructions.

Advantages of Embedding PEX Fittings in Concrete

1. Durability: Concrete provides excellent protection for the fittings, increasing their lifespan.

2. Concealment: Embedding the fittings in concrete conceals them from view, creating a clean and aesthetically pleasing finish.

3. Leak Prevention: The concrete surrounding the fittings forms a tight seal, preventing leaks and water damage.

Disadvantages of Embedding PEX Fittings in Concrete

1. Limited Access: Once the fittings are embedded in concrete, they are difficult to access for repairs or modifications.

2. Thermal Expansion: Concrete does not expand and contract at the same rate as PEX, which can lead to stress on the fittings over time.

3. Concrete Damage: If the concrete cracks or shifts, it can damage the fittings and compromise the plumbing system.

Alternatives to Embedding PEX Fittings in Concrete

If embedding PEX fittings in concrete is not feasible, consider these alternatives:

1. Chase and Studs: Cut a chase (groove) in the concrete and secure the PEX fittings with studs.

2. Surface Mount: Mount the PEX fittings directly onto the concrete surface using brackets or clips.

3. PVC Conduit: Encase the PEX fittings in PVC conduit and secure it to the concrete with clamps or straps.

Summary:

Embedding PEX fittings in concrete can be an effective solution for concealing and protecting plumbing lines. However, it’s crucial to follow the proper procedures and precautions to ensure the fittings remain functional and prevent potential problems. If you are unsure about the process, consult with a licensed plumber for guidance.

Basics You Wanted To Know

1. Can I use any type of PEX fitting in concrete?

• No, use only corrosion-resistant PEX fittings designed for concrete embedment.

2. How deep should I bury the PEX fittings in concrete?

• Deep enough to accommodate the fittings and provide space for expansion.

3. What type of sealant should I use around the fittings?

• Use a water-resistant sealant specifically designed for concrete applications.

4. Can I embed PEX fittings in existing concrete?

• Yes, but you may need to use a concrete saw to cut holes and ensure a proper fit.

5. How long should I wait before applying water pressure to the embedded fittings?

• Allow at least 28 days for the concrete to cure before pressurizing the system.