A well-designed cable railing system comes down to a few key principles: 3” to 4” spacing between cables, posts ideally at every 4 ft (maximum 6 ft) and at least 8 cable runs for 36" posts (9 minimum for 42" posts). 

Lacking inspiration? Explore our project gallery HERE! Ready to move forward with your cable railing project? Explore our ready-to-install kits or request a custom quote tailored to your space.

What is the spacing between cable railing cables?

To meet safety standards in Canada, cable spacing must prevent a 4-inch (100 mm) sphere from passing through.

In real-world applications, this typically translates to 3” to 4” spacing between cables, depending on tension and overall design.

This rule is critical because:

• It ensures child safety
• It keeps the railing compliant with building expectations
• It maintains a clean, uniform look

How far apart should cable railing posts be?

Cable railing posts are typically spaced at 4 feet apart, which is considered optimal for performance and aesthetics.

However, spacing can go up to a maximum of 6 feet depending on:

• The rigidity of the top rail
• The type of tensioners used
• The overall structure of the project

Key considerations:

• Closer spacing (≈4 ft) = better tension, less deflection, longer lifespan
• Wider spacing (up to 6 ft) = fewer posts, lower cost, but requires stronger framing

Intermediate posts are essential to:

• Keep cables straight and posts in place
• Reduce sag over time
• Maintain consistent spacing between cables

How many cables do I need for a railing?

The number of cables depends mainly on the height of your railing.

Typical configurations:

• 36” railing → 8 cable runs
• 42” railing → 9 to 10 cable runs

The goal is always to respect the maximum 4” spacing rule from top to bottom.

Adding more cables:

• Improves safety
• Enhances visual uniformity
• Slightly increases cost

How tight should cable railing cables be?

Cables should be tensioned enough to remain straight and resist movement, but not excessively tight.

General guideline:

• Tight enough that cables do not deflect easily when pushed
• Not so tight that it puts stress on posts or structure

Over-tensioning can:

• Damage posts
• Warp the structure
• Reduce long-term durability

Proper installation and gradual tensioning across all lines is key. Also, handrails must be installed before tensioning. 

Can I install cable railing myself?

Yes, cable railing systems are commonly designed for DIY installation.

Most projects can be completed with:

• Basic tools
• Clear measurements
• Step-by-step guidance

Key success factors:

• Accurate initial measurements
• Proper post alignment
• Even cable tensioning

This is why many systems (like ours) are built to be easy to assemble without specialized labor. Every single one of our cable railing kits comes with a video installation guide like this one.

What is the best cable size for railing?

The most commonly used cable specification is:

• 5/32” (4 mm) diameter
• 1x19 stainless steel construction

This type of cable offers:

• High strength
• Minimal stretch
• Clean, modern appearance

It is ideal for both residential and commercial applications.

Conclusion

When all of these elements are respected, you get a system that is safe, durable, clean-looking and built to last.

Ready to Get Started?

If you know what you are looking for, browse our cable railing hardware here. Most items are in stock and ship within 24 to 48 hours.

If you need a complete system with custom aluminum posts and handrail, request a quote here. Our team typically responds within one business day.

Questions? Call us at 1-418-524-0222 or email info@gauthierdelaplante.com. Monday to Thursday, 8:30 to 4:30, Friday until 1:00.

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