BalcoDeck® - Oxfordshire

Case Study: Solving Balcony Waterproofing Failures with an Integrated Deck & Balustrade Solution

Project Overview

Location: Oxfordshire
Balcony Size: Approx. 5.0m wide x 2.5m deep
Property Type: Residential, first-floor balcony above a habitable room

This project began with a problem many homeowners only discover after installation: a beautiful balcony that unfortunately caused ongoing waterproofing failures to the room below. The client approached us after experiencing repeated water ingress, looking for a permanent solution that would not risk further damage to their home.

The Original Problem

The property already had a completed deck and frameless glass balustrade installed on a first-floor balcony. Beneath this balcony was a fully habitable room, making waterproof integrity absolutely critical.

The original construction included:

• A short parapet wall (approximately 200–300mm high)
• A frameless balustrade mounted inside the parapet
• Balustrade fixings bolted directly through the waterproofing layer

Despite attempts at sealing around the fixings, water penetration occurred over time. Once waterproofing is pierced, even well-intentioned mitigation measures such as sealants can fail, leading to persistent leaks. In this case, the result was water ingress into the room below and a growing concern for long-term structural damage.

The client’s key requirement was clear: no further penetrations to the waterproofing, walls, or structure.

 

Exploring the Options

Two potential solutions were considered:

1. Face-Fixed Balustrade to the Outside of the Parapet

While this would avoid fixing through the balcony floor, it still required penetration into the building structure. Additionally, a site assessment showed that the existing parapet walls were unlikely to be strong enough to safely support a face-fixed balustrade.

2. An Integrated Deck & Balustrade System (BalcoDeck®)

The alternative was a fully integrated decking and balustrade solution that could be installed without any penetration to the waterproofing membrane.

After site discussions and a visit to our showroom, the client was particularly drawn to the BalcoDeck® solution, as it addressed both the technical issues and the aesthetic requirements of the balcony.

Design & Technical Challenges

As with many retrofit projects, there were constraints that required careful detailing.

Low Threshold Heights

The existing door thresholds were extremely low, and because this was a retrofit installation, there was no opportunity to alter window or door heights. This meant:

• The deck build-up had to be ultra-low, particularly close to the doors
• Drainage falls still had to be maintained

To overcome this, we developed a bespoke, ultra-low deck support solution for the first metre of the balcony, where the slope and thresholds were most critical.

Balustrade Integration

The deck system was designed to run continuously around the inside of the parapet wall. The balustrade was integrated into the deck structure itself rather than fixed through the waterproofing.

The chosen system was the Hybrid® Aerofoil balustrade, which allowed:

• Minimal posts (only a single post near the staircase)
• Post-free sections elsewhere
• Easier substructure design, crucial for maintaining the low deck height

On one side, the handrail was discreetly wall-mounted, further reducing the need for vertical posts.

Installation Process

The previous deck and balustrade had already been removed, and the waterproofing layer had been repaired before our installation began.

Despite challenging weather conditions, the installation was completed over three days:

Day 1 – Substructure Installation
The non-penetrative substructure was assembled directly above the waterproofing membrane, ensuring full protection of the layer beneath.

Day 2 – Decking & Balustrade Framework
Decking boards were installed, followed by the balustrade framework integrated into the deck system.

Day 3 – Glazing & Finishing Touches
Glass panels were fitted, final adjustments made, and detailing completed around the staircase interface.

The Result

​Picture Gallery: BalcoDeck - Oxfordshire - Picture Gallery

The completed balcony delivers a clean, modern appearance while completely eliminating the risk of future waterproofing failure.

Key outcomes include:

• Zero penetration through the waterproofing, parapet, or walls
• A fully compliant balustrade providing safe edge protection
• A visually striking deck and glass balustrade system
• Long-term peace of mind for the homeowner

Most importantly, the original issue of water ingress has been fully resolved.

Why This Matters

This project highlights a common issue with many traditional balustrade installations. Even when care is taken, any penetration through waterproofing creates a long-term risk. Sealants degrade, movement occurs, and water eventually finds a way in.

An integrated, non-penetrative decking and balustrade system avoids these risks entirely by supporting the balustrade above the waterproofing rather than through it.

Whether you already have a balcony experiencing leaks, or you’re planning a new installation, this case study demonstrates why considering waterproofing from the very beginning is essential.

Looking for a Waterproof-Safe Balcony Solution?

BalcoDeck® systems are designed specifically to protect waterproofing while delivering a premium finish. If you’re dealing with an existing waterproofing issue—or want to ensure you never have one—our team can help you find the right solution.