Historical Context and Manufacturer Background

The Cussins house, a notable example of post-war British architecture, was manufactured by Cussins Ltd. These properties were constructed between 1945 and 1946, a period marked by a significant housing shortage following World War II. The urgency to provide affordable and quickly built homes led to the development of various system-built properties, including the Cussins house. Approximately 3,500 of these houses were built, primarily in urban and suburban areas across the UK.

Cussins Ltd, the manufacturer, collaborated with designers to create a property that could be rapidly assembled while maintaining a reasonable standard of living. The Cussins house is also known by alternative names such as Cornes, Cornes Cussins, and Cussins Cornes, reflecting the variations in design and construction methods used during its production.

Identification Characteristics

Identifying a Cussins house involves recognizing several distinct features:

• Structure: These are typically 2-storey semi-detached houses.
• Roof: They feature a medium pitch gable roof covered with either clay pantiles or interlocking concrete tiles.
• External Walls: The walls are constructed from clay-slip-faced (unbonded pattern) or rendered PRC (Precast Reinforced Concrete) panels, or brick throughout.
• Windows: The window sizes vary, adding to the unique aesthetic of each property.
• Additional Structures: A single-storey brick outhouse is often attached to the gable wall.
• Entrance: A flat canopy over the front door is a common feature.

These characteristics make the Cussins house easily recognizable and distinguishable from other post-war housing types.

Construction Details

Substructure

The substructure of a Cussins house typically consists of concrete strip footings and a brick-faced reinforced concrete (RC) edge beam. A damp-proof course (DPC) is also included to prevent moisture from rising through the structure.

Main Frame

The main frame is composed of nine double RSC (Rolled Steel Channel) stanchions, each forming a hollow box. The frame also includes twelve RSJ (Rolled Steel Joist) perimeter beams, six RSJ floor and ceiling support beams, one RSJ trimmer beam, and RSC horizontal and vertical secondary framing. The frame members are connected using Kariscol joints, which are known for their strength and durability. The primary frame is coated with red oxide paint for protection, while the secondary frame is coated with black bituminous paint.

External Walls

The external walls are constructed from PRC panels faced with clay slips in an unbonded pattern. These panels are tied back to mild steel (MS) bars, creating a cavity that is filled with woodwool slabs for insulation. Variants of the Cussins house may feature brick external walls or rendered PRC panel external walls.

Separating Walls and Partitions

The separating wall between semi-detached units is typically a 9-inch brick wall. Internal partitions are made from timber studs lined with plasterboard. Variants may include woodwool slab cavity separating walls, concrete block separating walls, and metal and timber-framed partitions.

Floors

The ground floor is usually constructed with asphalt on concrete, while the first floor consists of tongue-and-groove (T&G) boarding on timber joists. Some variants may feature suspended ground floors with T&G boarding on timber joists.

Roof

The roof structure includes timber rafters, bituminous felt, timber battens, and interlocking concrete tiles. Some variants may have a clay pantile roof cover.

Typical Hazards and Risks

Corrosion

One of the primary concerns with Cussins houses is the corrosion of metal components. This includes minor corrosion of hollow box RSC stanchions, particularly at the bases and below the DPC, as well as minor corrosion of RSJ ground floor beams. Superficial corrosion of RSC secondary framing is also common. Additionally, corrosion of reinforcement in PRC panels, restraining hooks, associated rods, and spacers can occur.

Structural Issues

Displacement of PRC panels and cracking of mortar joints between PRC panels are typical structural issues. Cracking of brickwork and detachment of render are also common problems that can affect the integrity of the building.

Moisture and Damp

Due to the age of these properties, moisture ingress and dampness can be significant issues. The DPC may have deteriorated over time, allowing moisture to penetrate the structure. This can lead to further corrosion of metal components and degradation of building materials.

Defective Premises Act Considerations

The Defective Premises Act 1972 imposes a duty on builders, developers, and landlords to ensure that properties are constructed and maintained to a reasonable standard. While the Cussins house was built to address the urgent housing needs of the post-war period, some of the construction methods and materials used may not meet modern standards. As a result, these properties could be considered defective under the Act if they pose a risk to the health and safety of occupants.

Inspection Guide for Surveyors

When inspecting a Cussins house, surveyors should pay close attention to the following areas:

Foundation and Substructure

• Check for signs of subsidence or settlement: Look for cracks in the walls, floors, and around windows and doors.
• Inspect the DPC: Ensure it is intact and functioning correctly to prevent moisture ingress.

Main Frame

• Examine the RSC stanchions and RSJ beams: Look for signs of corrosion, particularly at the bases and below the DPC.
• Check the Kariscol joints: Ensure they are secure and free from significant corrosion.

External Walls

• Inspect the PRC panels: Look for signs of displacement, cracking, and corrosion of reinforcement.
• Check the render: Ensure it is intact and not detaching from the underlying structure.
• Examine the brickwork: Look for cracks and signs of movement.

Roof

• Inspect the roof covering: Check for missing or damaged tiles and ensure the bituminous felt is intact.
• Examine the timber rafters and battens: Look for signs of rot, insect infestation, and structural integrity.

Internal Walls and Partitions

• Check for cracks and movement: Look for signs of structural issues in the separating walls and partitions.
• Inspect the plasterboard: Ensure it is in good condition and free from significant damage.

Floors

• Examine the ground floor: Look for signs of dampness, cracking, and movement.
• Check the first floor: Ensure the T&G boarding and timber joists are in good condition and free from rot and insect infestation.

Common Defects in Cussins Houses

Corrosion

As previously mentioned, corrosion of metal components is a common issue in Cussins houses. This can affect the structural integrity of the building and may require remedial work to address.

Cracking

Cracking of mortar joints between PRC panels, brickwork, and internal walls is a typical defect. This can be caused by movement, settlement, or thermal expansion and contraction.

Moisture Ingress

Moisture ingress and dampness are common problems in older properties. This can lead to further issues such as rot, mould growth, and deterioration of building materials.

Render Detachment

The detachment of render from the external walls is a common issue. This can be caused by movement, moisture ingress, or poor adhesion of the render to the underlying structure.

Maintenance and Repair Considerations

Corrosion Treatment

Addressing corrosion in metal components is crucial to maintaining the structural integrity of a Cussins house. This may involve cleaning and treating the affected areas with rust inhibitors and protective coatings. In severe cases, replacement of corroded components may be necessary.

Crack Repair

Cracks in mortar joints, brickwork, and internal walls should be repaired to prevent further deterioration. This may involve repointing, filling, and sealing the cracks to prevent moisture ingress.

Damp Proofing

Improving the damp proofing of a Cussins house can help prevent moisture ingress and associated issues. This may involve repairing or replacing the DPC, installing a new damp proof membrane, and addressing any sources of moisture ingress.

Render Repair

Detached render should be repaired or replaced to protect the underlying structure. This may involve removing the damaged render, preparing the surface, and applying a new render coat.

Modernisation and Energy Efficiency

Insulation

Improving the insulation of a Cussins house can enhance energy efficiency and reduce heating costs. This may involve adding insulation to the cavity walls, roof, and floors. Modern insulation materials such as spray foam, rigid foam boards, and mineral wool can be used to achieve this.

Windows and Doors

Upgrading the windows and doors to modern, energy-efficient units can help reduce heat loss and improve the overall comfort of the property. Double or triple glazing, along with well-sealed frames, can significantly enhance thermal performance.

Heating Systems

Modernising the heating system can improve energy efficiency and reduce running costs. This may involve installing a new, energy-efficient boiler, upgrading radiators, and adding smart heating controls.

Renewable Energy

Incorporating renewable energy sources such as solar panels, heat pumps, and biomass boilers can further enhance the energy efficiency of a Cussins house. These systems can reduce reliance on fossil fuels and lower carbon emissions.

Conclusion

The Cussins house represents a significant chapter in the history of British housing. Built to address the urgent need for affordable homes in the post-war period, these properties have unique characteristics and construction methods that set them apart from other housing types. While they may present certain challenges, such as corrosion, cracking, and moisture ingress, with proper maintenance and modernisation, they can continue to provide comfortable and energy-efficient living spaces.

When considering the purchase of a Cussins house, it is essential to conduct a thorough inspection to identify any potential issues and assess the overall condition of the property. By understanding the typical construction methods, common defects, and maintenance requirements, buyers and investors can make informed decisions and ensure the long-term viability of their investment.

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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