Overview of the Glasgow Foamed Slag House

The Glasgow Foamed Slag house is a unique and historically significant type of property that emerged in the post-World War II era. Designed by J H Ferrie and W Kerr and manufactured by the Glasgow Corporation, these homes were constructed between 1946 and 1951. A total of 1,650 units, including flats, were built during this period. These properties are primarily found in Glasgow and surrounding areas, and they represent a fascinating chapter in the history of British housing.

Historical Context and Manufacturing Details

Post-War Housing Needs

The aftermath of World War II saw a significant housing shortage in the UK. The need for rapid and cost-effective housing solutions led to the development of various system-built properties, including the Glasgow Foamed Slag house. These homes were part of a broader effort to address the urgent demand for affordable housing.

Designers and Manufacturers

The Glasgow Foamed Slag house was designed by J H Ferrie and W Kerr, two prominent figures in the field of post-war housing design. The manufacturing was undertaken by the Glasgow Corporation, a local government body responsible for public housing in the city. The collaboration between these designers and the corporation resulted in a distinctive and innovative housing solution.

Identification Characteristics

Architectural Features

The Glasgow Foamed Slag house can be identified by several key characteristics:

• Bungalows and 2-Storey Semi-Detached Houses: These properties are typically either single-storey bungalows or two-storey semi-detached houses.
• Flat Roof Covered with Bituminous Felt: The flat roof is a notable feature, covered with bituminous felt for waterproofing.
• Rendered External Walls: The external walls are rendered throughout, providing a uniform appearance.
• Flat Canopy Over Front Door: A flat canopy over the front door is a distinctive architectural element.

Alternative Names

These properties are sometimes referred to by alternative names, but they are most commonly known as Glasgow Foamed Slag houses.

Construction Details

Substructure

The substructure details of the Glasgow Foamed Slag house are not well-documented. However, it is known that a damp-proof course (DPC) was used to prevent moisture ingress.

External Walls

The external walls are constructed using rendered 6″ storey height foamed slag aggregate precast concrete (PC) panels. These panels are designed to provide structural integrity and insulation.

Separating Walls

The separating walls between properties are made of 4″ storey height foamed slag aggregate PC panel cavity walls. This design helps to reduce sound transmission and improve thermal performance.

Partitions

Internal partitions are also constructed using 4″ storey height foamed slag aggregate PC panels, ensuring consistency in the construction materials used throughout the property.

Ground and First Floors

Both the ground and first floors are constructed using hollow PC beams. This method provides a lightweight yet strong flooring solution.

Roof

The roof is constructed using hollow PC beams, foamed slag aggregate screed, and bituminous felt. This combination provides durability and weather resistance.

Typical Hazards and Risks

Structural Concerns

One of the primary concerns with Glasgow Foamed Slag houses is the potential for structural issues. The use of foamed slag aggregate in the construction can lead to problems such as:

• Corrosion of Steel Reinforcement: Over time, the steel reinforcement within the concrete can corrode, leading to structural weaknesses.
• Carbonation: The concrete can undergo carbonation, which reduces its alkalinity and accelerates the corrosion of steel reinforcement.

Moisture Ingress

The flat roof design, while innovative, can be prone to moisture ingress if not properly maintained. The bituminous felt covering can deteriorate over time, leading to leaks and water damage.

Thermal Performance

While the foamed slag aggregate provides some insulation, these properties may not meet modern thermal performance standards. Upgrading insulation and improving energy efficiency can be a significant consideration for potential buyers.

Defective Premises Act

Classification as Defective

The Glasgow Foamed Slag house is not specifically classified as defective under the Defective Premises Act. However, the potential for structural issues and the need for ongoing maintenance mean that these properties require careful consideration and inspection.

Inspection and Assessment

Guidance for Surveyors

Surveyors inspecting Glasgow Foamed Slag houses should refer to several key resources for guidance on assessing reinforced concrete durability:

• Corrosion of Steel in Concrete (BRE Digest 444, Pts 1–3)
• Repair and Maintenance of Reinforced Concrete (BR 254)
• Carbonation Depths in Structural-Quality Concrete (BR 19)

These resources provide valuable information on identifying and addressing potential issues with reinforced concrete structures.

Inspection Checklist

When inspecting a Glasgow Foamed Slag house, surveyors should consider the following:

• Roof Condition: Check for signs of wear and tear on the bituminous felt covering and assess the overall condition of the flat roof.
• External Walls: Inspect the rendered external walls for cracks, spalling, or other signs of deterioration.
• Internal Partitions: Assess the condition of internal partitions and look for any signs of structural movement or damage.
• Moisture Ingress: Check for signs of moisture ingress, particularly around the roof and external walls.
• Thermal Performance: Evaluate the insulation and energy efficiency of the property, considering potential upgrades if necessary.

Typical Defects

Common Issues

Several common defects are associated with Glasgow Foamed Slag houses:

• Cracking and Spalling: Cracks and spalling in the concrete panels can indicate underlying structural issues.
• Corrosion of Steel Reinforcement: Corrosion of the steel reinforcement within the concrete can lead to significant structural weaknesses.
• Moisture Ingress: Leaks and water damage, particularly around the flat roof, can be a common issue.
• Thermal Performance: Insufficient insulation and poor energy efficiency can be a concern for modern homeowners.

Addressing Defects

Addressing these defects requires a thorough understanding of the construction methods and materials used in Glasgow Foamed Slag houses. Potential solutions include:

• Concrete Repairs: Repairing cracks and spalling in the concrete panels can help to restore structural integrity.
• Corrosion Protection: Applying corrosion protection measures to the steel reinforcement can help to prevent further deterioration.
• Roof Maintenance: Regular maintenance of the bituminous felt covering on the flat roof can help to prevent moisture ingress.
• Insulation Upgrades: Improving insulation and energy efficiency can enhance the comfort and performance of the property.

Conclusion

The Glasgow Foamed Slag house represents a unique and historically significant type of property in the UK. While these homes offer a fascinating glimpse into post-war housing design, they also come with potential risks and challenges. Understanding the construction methods, typical defects, and maintenance requirements is essential for anyone considering purchasing or investing in a Glasgow Foamed Slag house.

At Flettons, we’re committed to safeguarding your investment. When considering a property purchase, trust our seasoned expertise to reveal any hidden threats. For a thorough building survey, get your instant quote through our quote calculator or reach out directly at 0203 691 0451. Your home’s safety is our top priority.

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