The GC's statement that conduits and MC cables must exit the wall at a 90-degree angle to be properly sealed is likely incorrect and a misunderstanding of code requirements and sealing practices.

While a 90-degree exit can sometimes be a convenient configuration, it's not a mandatory requirement for a proper seal. The focus should be on achieving an effective and code-compliant seal, regardless of the angle.Here's a breakdown of why the GC is likely wrong and what you should consider

Why a 90-Degree Exit Isn't a Universal Requirement:
Sealing Methodology

The primary method of sealing around a conduit or MC cable where it exits a wall relies on sealant (like caulk, expanding foam, or specialized firestop materials) and the fitting or connector used. The effectiveness of the seal depends on:

Proper Application

The sealant must be applied correctly, filling all gaps and voids around the conduit/cable and adhering properly to both the wall and the conduit/cable jacket.

Appropriate Sealant

The right type of sealant must be chosen for the application. This depends on: Fire-resistance rating (if required) Environmental conditions (e.g., moisture, temperature) Compatibility with materials

Correct Fitting/Connector

The connector or fitting used must be appropriate for the type of conduit or cable and provide a secure connection to the electrical system. Some connectors are designed to compress and seal around the cable jacket.

Code Requirements Focus on Sealing Integrity

Building codes and the National Electrical Code (NEC) primarily focus on maintaining the integrity of fire-rated assemblies, preventing the spread of fire and smoke, and/or maintaining environmental separation (like preventing the intrusion of moisture or pests). They don't typically dictate the specific angle of the conduit/cable exit.

Practical Considerations

A rigid 90-degree exit can sometimes be impractical or even detrimental to a proper seal. For example:

Wall Irregularities

Walls are not always perfectly flat. Forcing a rigid 90-degree exit might create gaps that are difficult to seal effectively.

Strain on Conduit/Cable

If the run of conduit/cable isn't aligned perfectly with the wall surface, forcing a 90-degree exit can create stress on the conduit/cable and potentially compromise the seal over time.

MC Cable Flexibility

MC Cable's flexibility is an advantage. Restricting it to a 90-degree exit can make installation more difficult without providing a better seal.

Where Might a 90-Degree Angle Appear Important (and why it's still about the seal, not the angle)



Firestopping

In fire-rated walls, a clean, perpendicular penetration can simplify the application of firestop materials and ensure that the required depth of the firestop material is achieved consistently around the conduit or cable. However, even in these cases, a slight angle is usually acceptable as long as the firestop material is properly installed and meets the fire-resistance rating. The UL Listing of the firestop material must be followed precisely.

Aesthetics

In some cases, a consistent 90-degree exit might be preferred for aesthetic reasons, but this is a separate issue from proper sealing.

What to Do


Ask for Clarification and Documentation

Politely ask the GC to provide the specific code section, standard, or manufacturer's specification that requires a 90-degree exit for proper sealing. Ask them, "Can you show me where the code says the conduit/cable must exit at 90 degrees to be sealed?" They likely won't be able to provide concrete evidence.2.

Review the Project Specifications and Drawings

Check the project documents for any specific requirements related to conduit/cable penetrations and sealing. Pay close attention to sections on firestopping (if applicable) and any details about approved materials and installation methods.3.

Consult with an Electrical Inspector

If you're unsure about the code requirements or the best way to seal the penetrations, consult with your local electrical inspector. They can provide guidance on code compliance and acceptable sealing practices.4.

Focus on Proper Sealing Techniques

Ensure that all penetrations are sealed effectively using appropriate materials and methods. Follow the manufacturer's instructions for all sealants and firestop materials. Pay attention to these important points:

Surface Preparation

Clean the surfaces around the penetration to ensure proper adhesion of the sealant.

Backer Rod

Use backer rod in large openings to provide support for the sealant and control its depth.

Proper Tooling

Tool the sealant to create a smooth, professional finish and ensure a good seal.

Inspection

Inspect the seals after installation to ensure that there are no gaps or voids.5.

Document Your Work

Keep records of the materials used, the installation methods followed, and any inspections that were performed. This documentation can be helpful in the event of a dispute or future inspection.

In conclusion, the GC's statement is likely inaccurate. Focus on achieving a secure and code-compliant seal using the appropriate materials and methods, regardless of the angle of the conduit/cable exit. Prioritize the intent of the NEC and building codes, which is to ensure safety and prevent the spread of fire or environmental hazards. Flag for review