How to Safely Repair Plumbing and Run Electrical Wires Through Spray Foam Insulated Walls?

Mar 17

3 min read

Can You Repair Plumbing or Run New Electrical Wires in a Spray Foam Insulated Home?

Spray foam insulation is one of the best ways to seal air leaks, improve energy efficiency, and enhance home comfort. However, many homeowners wonder if it’s possible to repair plumbing or run new electrical wires through walls filled with spray foam.

The good news? It can be done, but the difficulty depends on whether your home has open-cell or closed-cell spray foam insulation.

Understanding Open-Cell vs. Closed-Cell Spray Foam

Open-Cell Spray Foam – Softer and more flexible, making it easier to cut through when running new wires or accessing pipes.
Closed-Cell Spray Foam – Denser and more rigid, providing better moisture resistance but harder to remove for repairs or modifications.

The type of insulation in your walls will determine the level of effort needed for plumbing or electrical work.

How to Repair Plumbing in a Spray Foam-Insulated Wall

1. Locate the Pipe Issue

Use a thermal camera or pipe locator to identify the exact spot of the plumbing problem.

2. Carefully Cut the Spray Foam

If your walls have open-cell spray foam, a utility knife or hand saw will typically be enough to cut through it.
If your walls have closed-cell spray foam, a reciprocating saw or oscillating tool will be needed to remove sections of insulation.

3. Repair or Replace the Pipe

Once the foam is cleared, proceed with repairing leaks, replacing damaged pipes, or installing new plumbing lines.

4. Re-Insulate the Area

Use spray foam in a can or foam board insulation to seal the section back up, maintaining your home's energy efficiency.

How to Run Electrical Wires Through Spray Foam-Insulated Walls

Option 1: Pre-Plan Before Insulation

If you're building or remodeling, always install electrical wiring before applying spray foam to avoid complications later.

Option 2: Fishing Wires Through Existing Spray Foam

If you need to add new wiring to an already insulated wall, follow these steps:

Locate the Electrical Path – Use a stud finder or infrared camera to avoid unnecessary cutting.
Drill a Small Access Hole – A small hole in the drywall at the top or bottom of the wall will allow a new wire to be fished through.
Use a Fish Tape or Flexible Drill Bit – This allows you to push or guide wires through the foam without removing large sections.
Seal Any Openings – After running wires, use fire-rated spray foam to seal any gaps while keeping safety codes in mind.

For open-cell spray foam, you can usually push wires through the insulation with minimal effort.For closed-cell spray foam, you may need to clear a pathway using a drill or specialized tools.

Best Practices for Plumbing & Electrical Work in Spray Foam Insulated Walls

Use Conduit for Future Accessibility – Running electrical wires or plumbing inside conduit before spraying foam makes future repairs much easier.
Cut Only What’s Necessary – Minimize insulation damage by carefully cutting just enough foam for the repair.
Follow Local Building Codes – Always ensure electrical and plumbing modifications meet safety regulations to avoid future issues.
Hire a Professional if Unsure – Spray foam insulation is tricky to work around. If you're uncertain, consult a licensed plumber or electrician.

Final Thoughts: Can You Work Around Spray Foam?

Yes, but it requires careful planning and the right tools. Open-cell spray foam is much easier to cut and remove, while closed-cell spray foam requires more effort but offers greater durability. Whether you're fixing a leak, installing new pipes, or running electrical wires, understanding the type of spray foam insulation in your home can help make the process smoother.