When considering a property purchase in the UK, understanding the intricacies of different property types is crucial. One such property type that often piques the interest of home buyers and investors is the Cornes house. This article delves into the essential aspects of Cornes houses, providing a detailed overview of their construction, typical characteristics, potential hazards, and inspection tips. As an expert surveyor, I aim to equip you with the knowledge needed to make informed decisions about these unique properties.

Historical Context and Manufacturers

The Cornes house, also known by alternative names such as Cornes Cussins, Cussins, and Cussins Cornes, was manufactured in 1964. These properties were primarily built by C Cornes & Son Ltd and Cussins Ltd, two prominent manufacturers in the construction industry during that period. The design and construction of these houses were influenced by the need for rapid housing solutions post-World War II, leading to the development of system-built properties.

Identification Characteristics

Cornes houses are typically 2-storey semi-detached and terraced houses. They can be identified by their shallow pitch gable roofs, which are covered with either bituminous felt or interlocking concrete tiles. The front and rear external walls are often clad with horizontal timber boarding, flat asbestos cement sheets, or plastics-coated steel sheets. These materials may be used throughout the structure or only on the first floor, with exposed aggregate precast concrete (PC) panels above.

The separating walls between properties are constructed using PC panels or brick, while the gable walls feature exposed aggregate PC panels, brick, or plastics-coated steel sheets that return around one corner. These distinctive features make Cornes houses relatively easy to identify.

Construction Details

Substructure

The substructure of Cornes houses consists of concrete pads below stanchions, a precast reinforced concrete (PRC) ground beam below the separating wall, and a PRC slab plinth. A damp-proof course (DPC) is also included to prevent moisture ingress.

Frame

The main frame of Cornes houses is composed of various steel components, including:
– 4 RS hollow box stanchions
– 4 RSC stanchions
– 9 RSC perimeter beams
– 2 RSJ floor support beams
– 1 RST ceiling support beam
– 5 support rods (2 for single-storey structures)
– 2 RSA trussed spandrel beams and RSA vertical struts
– 3 RSA roof trusses and diagonal bracings

These frame members are connected using Kariscol joints, ensuring structural stability.

External Walls

The front and rear external walls are constructed using storey-height timber-framed panels that incorporate doors and windows. These panels are clad with shiplap boarding and exposed aggregate PC panels, creating a cavity that is insulated with glass fibre and lined with foil-backed honeycomb plasterboard. The gable walls are clad with exposed aggregate PC panels throughout.

Separating Walls and Partitions

The separating walls between properties are timber-framed cavity walls lined with two layers of plasterboard, with glass fibre insulation between the frame studs. Internal partitions are made of honeycomb plasterboard.

Floors and Ceilings

The ground floor consists of chipboard on timber joists, while the first floor follows a similar construction. Ceilings are typically made of plasterboard.

Roof

The roof structure includes timber purlins, timber boarding, and bituminous felt. Some variants of Cornes houses feature interlocking concrete tiles as the roof covering.

Typical Hazards and Risks

While Cornes houses offer unique architectural features, they also come with certain hazards and risks that potential buyers and investors should be aware of.

Asbestos

One of the primary concerns with Cornes houses is the presence of asbestos cement sheets used in the external cladding. Asbestos poses significant health risks if disturbed, as inhaling asbestos fibres can lead to serious respiratory diseases, including asbestosis and mesothelioma. It is crucial to have a professional asbestos survey conducted before any renovation or demolition work.

Structural Integrity

The steel frame construction of Cornes houses, while robust, can be susceptible to corrosion over time, especially if the protective coating is compromised. Corrosion can weaken the structural integrity of the property, leading to potential safety hazards. Regular inspections and maintenance are essential to ensure the longevity of the steel frame.

Insulation and Energy Efficiency

The insulation materials used in Cornes houses, such as glass fibre and expanded polystyrene, may not meet modern energy efficiency standards. Upgrading the insulation can improve the property’s thermal performance, reduce energy bills, and enhance overall comfort.

Damp and Moisture

The presence of a damp-proof course (DPC) is intended to prevent moisture ingress; however, over time, the effectiveness of the DPC can diminish. Damp and moisture issues can lead to mould growth, which poses health risks and can damage the property’s structure. Regular inspections and maintenance of the DPC are necessary to mitigate these risks.

Defective Premises Act

Cornes houses are not typically classified as defective under the Defective Premises Act. However, it is essential to conduct thorough inspections to identify any potential defects or hazards that may require attention. Engaging a professional surveyor can help ensure that any issues are promptly addressed, safeguarding your investment.

Inspection Tips for Cornes Houses

When inspecting a Cornes house, it is crucial to pay attention to specific areas and potential issues. Here are some useful tips for a thorough inspection:

External Cladding

Inspect the external cladding for signs of damage, wear, or asbestos. If asbestos is present, ensure that it is in good condition and not disturbed. Consider engaging a professional asbestos surveyor for a comprehensive assessment.

Steel Frame

Examine the steel frame for signs of corrosion, particularly at connection points and areas exposed to moisture. Look for rust, flaking, or weakened joints. If corrosion is detected, consult a structural engineer for further evaluation and potential remediation.

Insulation

Check the insulation materials in the walls and roof. Ensure that they are in good condition and provide adequate thermal performance. Consider upgrading the insulation to meet modern energy efficiency standards if necessary.

Damp-Proof Course

Inspect the damp-proof course for any signs of deterioration or failure. Look for damp patches, mould growth, or musty odours, which may indicate moisture ingress. Address any issues promptly to prevent further damage.

Roof

Examine the roof covering for signs of wear, damage, or leaks. Check the condition of the bituminous felt or interlocking concrete tiles. Ensure that the roof structure, including timber purlins and boarding, is in good condition and free from rot or decay.

Internal Walls and Partitions

Inspect the internal walls and partitions for any signs of damage, cracks, or movement. Ensure that the honeycomb plasterboard is intact and provides adequate structural support. Address any issues promptly to maintain the integrity of the property.

Typical Defects in Cornes Houses

Understanding the common defects in Cornes houses can help you identify potential issues during inspections and make informed decisions about repairs and maintenance.

Corrosion of Steel Frame

As mentioned earlier, the steel frame of Cornes houses can be susceptible to corrosion, particularly in areas exposed to moisture. Regular inspections and maintenance are essential to prevent structural weakening and ensure the longevity of the property.

Asbestos-Related Issues

The presence of asbestos cement sheets in the external cladding poses significant health risks if disturbed. It is crucial to handle asbestos with care and engage professional asbestos surveyors for safe removal or encapsulation.

Damp and Moisture Problems

Damp and moisture issues can arise due to the deterioration of the damp-proof course or inadequate ventilation. These issues can lead to mould growth, which poses health risks and can damage the property’s structure. Regular inspections and maintenance of the DPC and ventilation systems are necessary to mitigate these risks.

Insulation and Energy Efficiency

The insulation materials used in Cornes houses may not meet modern energy efficiency standards. Upgrading the insulation can improve the property’s thermal performance, reduce energy bills, and enhance overall comfort.

Roof Leaks and Damage

The roof covering, whether bituminous felt or interlocking concrete tiles, can deteriorate over time, leading to leaks and water damage. Regular inspections and maintenance of the roof are essential to prevent further damage and ensure the property’s integrity.

Variants of Cornes Houses

Cornes houses come in various variants, each with unique characteristics and construction details. Understanding these variants can help you identify specific features and potential issues during inspections.

External Wall Cladding

Some variants of Cornes houses feature external wall cladding made of flat asbestos cement sheets or plastics-coated steel sheets. These materials may be used throughout the structure or only on the first floor, with exposed aggregate PC panels above.

Insulation

Certain variants of Cornes houses are insulated with expanded polystyrene, which may not meet modern energy efficiency standards. Upgrading the insulation can improve the property’s thermal performance and reduce energy bills.

Gable Wall Construction

The gable walls of some Cornes houses are constructed using brick, which returns around one corner. This construction detail can provide additional structural stability and aesthetic appeal.

Roof Covering

While the standard roof covering for Cornes houses is bituminous felt, some variants feature interlocking concrete tiles. These tiles can provide enhanced durability and weather resistance.

References and Further Reading

For more detailed information on the inspection and assessment of steel-framed houses, the following references can be useful:

• CIBSA 1967
• NBA Certificate February 1966
• Steel framed and steel clad houses: inspection and assessment (BR 113)
• Inspecting steel houses (IP 14/87)
• Maintaining and improving steel houses (IP 15/87)

These references provide valuable guidance on inspecting and maintaining steel-framed properties, including Cornes houses.

Conclusion

Cornes houses, with their unique construction and historical significance, offer a distinctive option for home buyers and investors in the UK. Understanding the typical characteristics, potential hazards, and common defects of these properties is essential for making informed decisions. Regular inspections and maintenance are crucial to ensure the longevity and safety of Cornes houses.

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.