Non-Penetrative Steel Sub Frames

Designed, Supplied & Installed with Comprehensive Structural Reports

Protecting waterproofing. MITIGATING thermal bridging.

Modern balconies, terraces and elevated structures require more than simple structural support. Waterproofing systems, insulation layers and thermal performance must all work together to ensure long-term building performance.

Traditional fixing methods often require penetrations through waterproof membranes and insulated build-ups, creating potential risks for water ingress, thermal bridging and long-term maintenance issues.

360 GSS designs, fabricates and installs bespoke non-penetrative steel sub frame systems that provide structural support while helping preserve waterproofing integrity and thermal efficiency. Every system is engineered around the specific structural, architectural and loading requirements of the project, ensuring a practical solution that supports both performance and compliance.

No Penetrative Steelwork & System Specifications

All non-penetrative steel sub frame systems are manufactured to meet both structural and architectural requirements:

  • Bespoke structural steel sub frames fabricated in-house
  • Designed to support balconies, terraces, walk-on structures and elevated platforms
  • Engineered to help reduce penetrations through waterproofing systems
  • Designed to minimise thermal bridging within modern building envelopes
  • Structural calculations and comprehensive technical reports available
  • Galvanised, powder-coated and specialist protective finishes available
  • Fabricated to suit project drawings, engineering requirements and site conditions

Every system is measured, fabricated, supplied and installed by experienced specialists with awareness of LABC guidance, Building Regulations and relevant British Standards.

our process

STEP 1

Request a Quote

how to get a custom glass quote
Share your drawings, specifications or project details so our team can assess the structural and waterproofing requirements.
STEP 2

site survey & measure

steel post glass balustrade survey
A detailed survey is carried out to assess the structure, build-up, access and installation requirements.
STEP 3

DEPOSIT, Design & Engineering

glass partition designer and install
Once approved, a 50% deposit secures your project and allows final design development, structural calculations and engineering work to begin.
STEP 4

Manufacturing of the System

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Steel sub frames are fabricated in-house to ensure quality control, accurate fitment and efficient project delivery.
STEP 4

Install & completion

non penetrative steel sub frame
Installation is completed by experienced professionals with careful attention to structural integrity, waterproofing protection and finish quality.

Engineered for Modern Construction

A non-penetrative steel sub frame must do more than support the structure above. It must integrate with modern construction methods while protecting the wider building envelope.

Our bespoke systems are designed to:

  • Support balconies, terraces and elevated structures
  • Help maintain the integrity of waterproofing systems
  • Reduce the risk of thermal bridging
  • Integrate with insulated roof and terrace build-ups
  • Meet structural and safety requirements
  • Provide long-term durability and stability
  • Minimise future maintenance concerns
  • Support residential and commercial developments

With extensive experience supporting glazing, balustrade, balcony and structural steel projects, 360 GSS provides practical solutions for complex construction challenges.

Why choose 360 gss?

HUNDREDS OF INSTALLS

Proven experience across a wide range of residential and commercial projects.

SPECIALIST INSTALLERS

Every project is handled by skilled professionals to ensure accuracy and quality.

UK MANUFACTURED

We use high-quality UK manufactured materials to ensure reliability, consistency and long-term performance.

ALL WORK GUARANTEED*

Long-term confidence backed by a comprehensive guarantee.

FAST LEAD TIMES

Fast lead times with consistent project delivery.

FULL DESIGN SUPPORT

Guidance at every stage to achieve the right solution for your space.

FREQUENTLY ASKED QUESTIONS

If you cannot find the answer to your welding or fabrication questions below, our team is happy to help – call us on 01494 971 694 or email info@360gss.co.uk for expert advice.

Ready to get in touch?

If your project requires a structural support solution that protects waterproofing systems while reducing thermal bridging, a non-penetrative steel sub frame could be the ideal solution.

360 GSS provides design, fabrication and installation services across London, Buckinghamshire, Berkshire, Oxfordshire, Hertfordshire, Surrey and throughout the UK for suitable projects.
What is a non-penetrative steel sub frame?
A non-penetrative steel sub frame is a structural support system designed to reduce or eliminate the need for fixings through waterproof membranes and insulated roof or terrace build-ups.
They help protect waterproofing systems, reduce the risk of water ingress and minimise thermal bridging within the building envelope.
They are commonly used to support balconies, roof terraces, glass balustrades, walk-on structures and other elevated architectural features.
Yes. We can provide structural calculations and comprehensive technical reports to support the design and approval process.
Yes. All steel sub frames are fabricated in-house, allowing greater quality control, faster turnaround times and accurate project-specific manufacturing.
Yes. Our systems are suitable for both residential and commercial developments and can be tailored to meet project-specific requirements.