Okay, let's break down the situation and address the potential prohibitions or considerations when securing 1" conduit to existing securement means in a garage built two years ago. There haven't been new sweeping prohibitions, but there are best practices, code-related concerns, and specific situations that might apply.

Key Considerations and Potential Issues


Original Intent of the Securement



Load Capacity

Was the existing securement (e.g., a joist hanger, a bracket) originally designed to hold only its current load, or was it over-engineered with extra capacity? You need to be absolutely certain adding the weight of the conduit and its contents won't overload the existing structure or securement. Overloading could lead to failure, potentially causing damage or injury.

Vibration and Stress

Will the added conduit introduce vibration or stress to the existing structure that it wasn't designed to handle? Conduit carrying wires can vibrate, especially if it's a long run.

Corrosion

Introducing dissimilar metals (e.g., galvanized conduit attached to a steel bracket) can lead to galvanic corrosion. Consider using isolation methods if dissimilar metals are unavoidable.2.

Code Compliance (Primarily NEC)



Support Spacing (NEC 352.30, 344.30)

The National Electrical Code (NEC) dictates how often conduit needs to be supported. For 1" rigid metal conduit (RMC), intermediate metal conduit (IMC), or PVC conduit, the support spacing is typically every 10 feet. For EMT, the support spacing is typically every 10 feet. Check the specific conduit type you're using and the NEC article covering it. You can't just rely on existing securement points unless they meet these spacing requirements.

Securely Fastened (NEC 300.11)

This is a broad requirement that electrical wiring must be securely fastened in place. Improvising connections without considering the long-term security is a violation. Improper connections can loosen over time, leading to hazards.

Dedicated Support (NEC 300.11(D))

The NEC generally prefers electrical wiring (including conduit) to be supported independently of other systems (like plumbing, HVAC, etc.). This doesn't completely prohibit sharing support, but it requires careful consideration and adherence to other code requirements. The key is ensuring the electrical system is independently secure.3.

Coordination with Other Trades



Communication is Key

Always communicate with the other trades involved (plumbers, HVAC technicians, carpenters) before attaching to their supports. They may have reasons why it's not suitable (e.g., planned maintenance, future expansion, weight restrictions).

Respect Their Work

Don't drill into or modify existing supports without permission. You could compromise their integrity.

Documentation

If you do share support, document it clearly, including the rationale, calculations (if any), and any agreements made with the other trades.4.

Type of Garage Structure



Wood Frame

If it's a typical wood-framed garage, you can often add your own appropriate fasteners (screws, nails, etc.) to the framing members (joists, studs). Ensure you're using fasteners rated for the intended load and that you're not over-driving them, which can weaken the wood.

Concrete Block/Masonry

Attaching to concrete block requires specialized anchors designed for the load.

Metal Frame

If the garage has a metal frame, you'll need appropriate fasteners (self-tapping screws, bolts) designed for metal.5.

Aesthetic Considerations

While not a code issue, consider the overall appearance. A haphazardly attached conduit run can look unprofessional.

Why "Teeing off a Plumber" is a Common Example

The prohibition against teeing off of a plumber is pretty much, do not support your electrical conduit off of the plumbing pipe.

Movement and Vibration

Plumbing pipes, especially those carrying water under pressure, can move and vibrate. This movement can transfer to the conduit, potentially loosening connections or causing stress on the wiring.

Corrosion

Dissimilar metals between the conduit and plumbing can accelerate corrosion.

Maintenance

Plumbing systems often require maintenance or repair. Having conduit attached to the plumbing can make these tasks more difficult.

When Sharing Securement Might Be Acceptable (with caution and proper planning)



Engineer's Approval

If there's any doubt about the structural capacity, consult with a structural engineer. They can perform calculations to determine if the existing securement can handle the additional load.

Dedicated Straps/Clamps

Use dedicated straps or clamps designed to securely attach the conduit to the existing support. Avoid using zip ties, wire, or other makeshift methods.

Isolation

Use isolation materials (e.g., rubber grommets, plastic spacers) to prevent direct contact between dissimilar metals and to dampen vibration.

Clearance

Ensure there's sufficient clearance around the conduit and existing systems for maintenance and future modifications.

Minimal Load

If the conduit is a short run with very little weight (e.g., a short run of empty conduit), it might be acceptable to share support, but still with careful consideration and secure attachment.

In Summary:

While there isn't a blanket new* prohibition on sharing securement, it's generally best practice to avoid it unless absolutely necessary. If you do share, prioritize safety, code compliance, and communication with other trades. Always assess the load capacity, potential for vibration, and compatibility of materials. When in doubt, add your own dedicated support system for the conduit.If there is any doubt, consult with a qualified electrician or electrical inspector. Flag for review