RGV I & RGV II

Rear Ventilated Waterproofing Systems

Developed by The German Roofer

Those innovative systems were specifically designed to address challenges faced by five flat roofs that experienced extensive water damage and dampness due to failed waterproofing applications. The original installations suffered from poor workmanship, resulting in leaks, damp ceilings, and walls–compounded by thermal bridging.

Problem Overview

1. Initial Failure:

• Poorly executed waterproofing led to leaks, causing significant water infiltration.

• Thermal bridges allowed unwanted heat transfer, increasing energy inefficiency and condensation risks.

2. Ineffective Repairs by Other Providers:

• Superficial patches addressed symptoms temporarily but failed to resolve root causes.

• Resulted in further damage to screed and plaster, weakening compressive strength.

3. Long-Term Risks:

• Accelerated structural damage from corrosion and water saturation.

• Threatened overall integrity of the building.

The Solution

Rear Ventilation Waterproofing Systems:

Designed to address both immediate leaks and long-term structural risks, the systems provide:

1. Air Insulation Layer (benefits can be increased when installed from the start with insulation beneath waterproofing layers) 

• Introduced between the existing waterproofing and the new system

• Mitigates condensation and controls moisture more effectively

2. Enhanced Airflow

• Standing water evaporates through constant ventilation.

3. Thermal Benefits

• Provides passive seasonal advantages:

• Winter: Heat retention reduces energy loss

• Summer: Passive cooling minimizes heat gain

4. Added Advantages

• Improves insulation, reducing heating and cooling costs

• Protects structural components by reducing water exposure

Outcome

Verified Success:

• Thermal scans and independent third-party leak detection confirmed the roof is completely dry

Prepared for Final Touches

• Ready for cladding with custom German RHEIN ZINK parapet flashing’s installed by master craftsmen

Application Process

Efficient:

• Fast installation, even in adverse weather conditions

Components:

• Rear ventilated parapets ensure airflow between the old and new waterproofing

• Seamless aluminum window flashing systems are integrated

Inspection and Compliance

Inspected and approved by:

• Leading waterproofing suppliers

• Double glazing window specialists

• Sealant and repair mortar suppliers/importers

• Architects and structural engineers

All installations adhere to strict building regulations

Warranty

• Workmanship:

3 years (insurance-backed by The German Roofer)

• Materials:

10 years (backed by the waterproofing supplier and insurance)

Advantages of Rear Ventilated Systems

Thermal Benefits:

• Energy Efficiency

• Reduces heat transfer through the building envelope

• Minimizes reliance on HVAC (heating, ventilation, and air conditioning) systems, leading to lower energy costs

• Seasonal Comfort:

• Improved indoor temperatures year-round

Moisture Control

• Eliminates condensation risks, preventing mold and material degradation

Structural Durability

• Long-term protection of screed, plaster, and other structural elements

Acknowledgments

A special thanks to our clients, suppliers, and the dream team of “The German Roofers” for bringing this project to life with innovation and expertise

RGV I - Rear Ventilated Parapet System (developed by The German Roofer)
RGV II - Rear Ventilated Window Flashing System (developed by The German Roofer)