Introduction

Grounding an old house can be challenging, especially if you want to avoid the messy and disruptive process of tearing out walls and ceilings to access the electrical system. Proper grounding is crucial for safety, protecting against shocks and blown fuses. In this comprehensive guide, I will walk through various methods for grounding an old house while keeping the existing plaster intact.

Assess the Existing Electrical System

The first step is to thoroughly inspect the existing electrical system and components. This will help you understand what needs to be upgraded or replaced for proper and safe grounding.

Creating a detailed assessment highlights what grounding solutions will be viable for your unique old home's needs.

Improve Grounding at the Main Panel

Updating the main electrical panel is key for creating a safe grounding system. But choosing the right approach depends on your existing panel.

Upgrade to a Grounding Panel

If the electrical panel is very old or undersized, the best option is upgrading to a full grounding panel. This gives you:

Upgrading the main panel resolves grounding at the central source. But don't stop here - you still need proper grounding through all wires and outlets.

Add a Ground Rod

If the panel itself doesn't need replacement, adding a ground rod creates a basic grounding system.

This DIY ground rod install is low cost. But it has limitations depending on soil conditions and alone may not fully ground the system.

Install a Subpanel

Another option without replacing the main panel is installing a grounded subpanel.

The existing ungrounded wiring connects to the subpanel, which distributes grounded power. It's a good compromise option.

Update Outlets and Wiring

Once the main panel/subpanel is grounded, the next step is replacing ungrounded wiring and outlets throughout the home.

Replace Outlets

Updating all outlets, room by room, ensures accessible grounded plugs anywhere needed.

Re-Wire Circuits

For a full grounding solution:

Re-wiring upgrades old cloth-coated wire while minimizing plaster demolition. Opening walls in a few key spots allows access for pulling new wire.

Use Grounding Plates

Grounding plates are another option that keeps plaster walls intact.

Use grounding plates on boxes with grounded wiring. It's quick and doesn't require new wire.

Install GFCI Outlets

While not a full grounding solution, adding GFCI outlets enhances safety:

Use GFCI outlets selectively in combination with other methods. Don't rely only on GFCIs for grounding an old system.

Conclusion

While daunting, grounding an old home without demolition is very feasible. Start by evaluating the existing system then make incremental upgrades. Replace the main panel, re-wire circuits and add ground rods and plates. With proper attention to detail, an old house can have a safe, grounded electrical system.