Indoor Coaxial Cable: The Complete Guide

Published by Wassalat Technical Team

While outdoor cables face harsh environmental challenges, indoor coaxial cables have their own unique requirements—fire safety, flexibility, space constraints, and interference management are all critical factors to consider.

This comprehensive guide covers everything you need to know about indoor coaxial cables—from plenum ratings to installation techniques, and from residential wiring to commercial infrastructure.

Why Indoor Cables Are Different

Indoor coaxial cables face challenges that outdoor cables don't:

Indoor Environment Challenges

Indoor Cable Types

Indoor coaxial cables are categorized by their jacket material and fire rating:

1. PVC (Polyvinyl Chloride)

Fire Rating: Standard (not plenum)

Jacket Color: Usually white, black, or gray

Best For: Residential, home theaters, standard office wiring

Pros: Affordable, flexible, easy to work with

Cons: Produces toxic smoke when burned; not allowed in plenum spaces

Common Use: Cable TV, satellite, antenna connections

2. Riser (CMR – Communications Multipurpose Cable, Riser)

Fire Rating: Riser-rated

Jacket Color: Usually white or gray

Best For: Vertical risers, between floors

Pros: Flame retardant, reduces fire spread

Cons: More expensive than PVC

Common Use: Multi-story buildings, commercial installations

3. Plenum (CMP – Communications Multipurpose Cable, Plenum)

Fire Rating: Plenum-rated

Jacket Material: FEP (Fluorinated Ethylene Propylene) or FRPVC

Jacket Color: Usually white, blue, or yellow

Best For: Air handling spaces, dropped ceilings, HVAC plenums

Pros: Low smoke, low toxicity, fire retardant

Cons: Most expensive, stiffer jacket

Common Use: Commercial buildings, schools, hospitals, offices

4. LSZH (Low Smoke Zero Halogen)

Fire Rating: Low smoke, halogen-free

Jacket Material: Polyolefin-based compound

Best For: Enclosed spaces, sensitive environments

Pros: No toxic gas, minimal smoke

Cons: More expensive

Common Use: Ships, submarines, tunnels, data centers

Plenum vs Riser vs PVC: What's the Difference?

Plenum Spaces

What is a plenum space?

An air handling space used for heating, ventilation, and air conditioning (HVAC). Typically found in:

• Dropped ceilings
• Raised floors
• Air ducts
• HVAC return plenums

Cable Requirement: Plenum-rated (CMP)

Why: Standard PVC cables can release toxic smoke when burned, which would spread through the building via the air system.

Riser Spaces

What is a riser space?

Vertical shafts that run between floors in a building. Typically found in:

• Elevator shafts
• Electrical closets
• Telecom rooms
• Vertical cable shafts

Cable Requirement: Riser-rated (CMR)

Why: Cables in vertical shafts can spread fire between floors. Riser-rated cables resist flame spread.

General Purpose (PVC)

What is a general purpose space?

Standard indoor areas not used for air handling or vertical shafts:

• Living rooms
• Bedrooms
• Offices
• Retail spaces

Cable Requirement: General purpose (CM/CMG)

Why: Lower fire risk areas where standard PVC cables are acceptable.

Cable Rating Comparison

RG6 Indoor Cable

RG6 is the most common indoor coaxial cable for residential and commercial video applications.

RG6 Indoor Specifications

RG6 Indoor Applications

• ✅ Cable TV (CATV) – Throughout homes and offices
• ✅ Satellite TV – Indoor runs from wall plates to receivers
• ✅ Broadband Internet – Cable modem connections
• ✅ Home Theater – Video distribution
• ✅ Backbone Wiring – Small building distribution

RG59 Indoor Cable

RG59 is a thinner, more flexible cable used for short indoor video runs and CCTV applications.

RG59 Indoor Specifications

RG59 Indoor Applications

• ✅ CCTV Patch Cables – Short camera connections
• ✅ Video Patch Panels – Studio equipment interconnections
• ✅ Consumer Video – DVD players, game consoles
• ✅ Test Equipment – Laboratory connections
• ✅ Temporary Installations – Quick setups

Indoor Cable Comparison Table

Indoor Applications

1. Residential (Homes & Apartments)

Recommended Cable: PVC RG6 (CM-rated) with white jacket

Typical Uses:

• ? Cable TV distribution
• ? Satellite TV (receiver to wall plate)
• ? Cable broadband internet
• ? Home theater connections

Installation Tip: Use white cable to blend with walls and baseboards.

2. Commercial Offices

Recommended Cable: Plenum RG6 (CMP) or Riser RG6 (CMR)

Typical Uses:

• ? Video distribution systems
• ? Conference room AV systems
• ? Building-wide internet distribution

Installation Tip: Check local building codes for required cable ratings.

3. Hotels & Hospitality

Recommended Cable: Plenum RG6 (CMP) for public areas, PVC RG6 for rooms

Typical Uses:

• ? In-room TV distribution
• ? Satellite TV (head-end to rooms)
• ? Conference/event AV systems

Installation Tip: Use plenum-rated cable in corridors and common areas.

4. Data Centers

Recommended Cable: LSZH or Plenum-rated

Typical Uses:

• ? RF distribution
• ? Video monitoring systems
• ? Network infrastructure

Installation Tip: LSZH is preferred for data centers to minimize risk in case of fire.

Installation Best Practices

1. Plan Your Routes

• ✅ Map out cable paths before installation
• ✅ Identify obstacles (studs, pipes, electrical wiring)
• ✅ Choose shortest possible path
• ✅ Plan for service loops at each end

2. Keep Away from Interference Sources

3. Use Proper Supports

• ✅ Use cable clips or staples (don't crush the cable)
• ✅ Support every 3-5 feet
• ✅ Use J-hooks for ceiling installations
• ✅ Use cable trays for large bundles

4. Avoid Sharp Bends

• ✅ Maintain minimum bend radius
• ✅ RG6: 2-3 inches
• ✅ RG59: 1.5-2 inches
• ✅ Use sweep bends (90° sweeps, not sharp corners)

5. Protect from Physical Damage

• ✅ Use conduit in exposed areas
• ✅ Use wall plates at termination points
• ✅ Avoid running across walking areas
• ✅ Secure cables away from moving parts

6. Label Everything

• ✅ Label both ends of each cable
• ✅ Use clear, readable labels
• ✅ Document cable routing
• ✅ Include date and installer info

Fire Safety & Building Codes

Understanding building codes is essential for indoor cable installations.

NEC (National Electrical Code) Requirements

Article 800 – Communications Circuits

The NEC specifies cable requirements based on location:

Common Code Violations

• ❌ Using PVC cable in plenum spaces
• ❌ Using PVC cable in riser shafts
• ❌ Overfilling conduits
• ❌ No cable supports
• ❌ Exceeding bend radius limits
• ❌ No fire-stopping at floor penetrations

Frequently Asked Questions (FAQ)

1. Can I use outdoor cable indoors?

Yes, outdoor cable can be used indoors. However, it's stiffer and harder to work with than indoor cable. It's also more expensive than necessary.

2. What's the difference between plenum and riser cable?

Plenum cable (CMP) is designed for air handling spaces and produces minimal smoke when burned. Riser cable (CMR) is designed for vertical shafts and resists flame spread between floors.

3. Can I use PVC cable in a commercial building?

Only in non-plenum, non-riser spaces. Check local building codes. Many commercial buildings require plenum or riser-rated cable throughout.

4. What color is indoor coaxial cable?

White is most common for residential installations. Commercial cables come in white, blue, yellow, gray, and black. Color doesn't affect performance.

5. Can I run coax cable through walls?

Yes. Use in-wall rated cable (CM, CMR, or CMP depending on location). Use wall plates with F-Type connectors at termination points.

6. Can I run coax cable next to electrical wiring?

Avoid running coax parallel to electrical wiring. Maintain 12+ inches of separation. Cross at 90° angles when necessary.

7. How do I terminate indoor coax cable?

Use a coaxial stripper to prepare the cable, then attach a compression F-Type or BNC connector. Always test after termination.

8. What is the maximum length for indoor RG6?

For cable TV and satellite, RG6 can run up to 150-200 feet indoors. For longer runs, use RG11 or a signal amplifier.

9. Can I use RG6 for audio?

Yes, RG6 can be used for digital audio (S/PDIF) and some analog audio applications. However, dedicated audio cables are often preferred.

10. What is the best coax cable for in-wall installation?

For residential in-wall, use riser-rated (CMR) RG6 with dual shield. For commercial in-wall, use the appropriate cable for your local building codes.

11. Is LSZH cable required by code?

LSZH is not typically required by building codes but is often specified for data centers, ships, and tunnels where halogen-free cable is preferred.

12. Can I splice indoor coax cable?

Yes, using F-Type barrel connectors. However, each splice adds signal loss. Use a continuous cable when possible.

? Related Articles

• Complete Guide to Coaxial Cables
• Outdoor Coaxial Cable
• Coaxial Cable Construction
• RG6 vs RG11
• Coaxial Cable Connectors Guide
• Best Coax Cable for TV
• Browse Coaxial Cables →

Last Updated: July 2026

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