Overview of the KenKast House

The KenKast house, also known as Kencast, is a distinctive type of system-built property that emerged in the 1960s. Manufactured by KenKast Buildings Ltd, these homes were designed to address the post-war housing shortage in the UK. Approximately 1,000 units were constructed, primarily as detached and semi-detached bungalows. These properties are notable for their medium pitch gable roofs, external rendered walls, and tile hanging at the gable apex. Some variations also feature vertical timber boarding below the front wall windows.

Historical Context and Manufacturing Details

Period of Construction

The KenKast houses were built during the 1960s, a period marked by a significant demand for affordable and quickly constructed housing solutions. This era saw the rise of various system-built properties, which were designed to be assembled rapidly on-site using pre-fabricated components.

Manufacturer and Designer

KenKast Buildings Ltd was the manufacturer behind these innovative homes. While the specific designer is not widely documented, the design reflects the architectural trends and construction technologies of the time, focusing on efficiency and cost-effectiveness.

Typical Locations

KenKast houses can be found in various parts of the UK, often in suburban areas where there was a need for rapid housing development. These properties were particularly popular in regions that experienced significant population growth during the post-war period.

Characteristics and Construction Details

Identification Characteristics

KenKast houses are easily identifiable by their distinct features:
– Detached and semi-detached bungalows.
– Medium pitch gable roofs covered with slates or tiles.
– External walls rendered throughout.
– Tile hanging at the gable apex.
– Some bungalows have vertical timber boarding below some front wall windows.

Construction Details

Substructure

The substructure of KenKast houses typically includes concrete pads below columns and a concrete raft foundation. A damp-proof course (DPC) is also present to prevent moisture ingress.

External Walls

The external walls are constructed using 6-inch pre-cast reinforced concrete (PRC) kerb units and 6-inch square storey height PRC columns. These walls are rendered and consist of 3-inch by 2-foot by 3-foot 3-inch PRC slabs reinforced with 1/8-inch steel mesh. The slabs are bolted together with 8 1/2-inch by 1/4-inch bolts. Timber fillets impregnated with preservative and polystyrene-backed plasterboard are also used in the construction. Tile hanging is nailed to timber battens secured to the gable end roof truss.

Internal Partitions

Internal partitions are typically made of timber stud lined with plasterboard.

Ground Floor

The ground floor construction includes brown asphalt on felt underlay on concrete.

Ceilings

Ceilings are constructed using plasterboard.

Roof

The roof structure comprises timber rafters and purlins, covered with slates or tiles.

Variants

Some KenKast bungalows feature external front walls made of storey height timber frame panels clad with vertical tongue and groove (T&G) timber boarding, backed with bituminous felt on timber studding.

Typical Hazards and Risks

Structural Issues

One of the primary concerns with KenKast houses is the potential for structural issues, particularly related to the pre-cast reinforced concrete (PRC) components. Over time, these components can deteriorate, leading to hairline cracking between the components. This can compromise the structural integrity of the property.

Moisture Ingress

The presence of a damp-proof course (DPC) is crucial in preventing moisture ingress. However, if the DPC is compromised or not properly installed, it can lead to damp issues within the property.

Timber Decay

The timber elements used in the construction, such as the timber fillets and timber battens, are susceptible to decay if not properly treated or maintained. This can lead to further structural issues and potential safety hazards.

Insulation and Energy Efficiency

KenKast houses were built during a time when energy efficiency was not a primary concern. As a result, these properties may have inadequate insulation, leading to higher energy costs and a less comfortable living environment.

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 KenKast houses were innovative for their time, the potential structural issues and other hazards associated with PRC components mean that these properties could be considered defective under the Act if they have not been properly maintained or if significant deterioration has occurred.

Inspection Guide for Surveyors

External Inspection

Roof

• Check the condition of the slates or tiles on the roof.
• Inspect the timber rafters and purlins for signs of decay or damage.
• Examine the tile hanging at the gable apex for any loose or missing tiles.

Walls

• Look for hairline cracking between the PRC components.
• Check the condition of the render on the external walls.
• Inspect the timber boarding below the front wall windows for signs of decay.

Foundation

• Examine the concrete pads and raft foundation for any signs of movement or cracking.
• Ensure the damp-proof course (DPC) is intact and functioning properly.

Internal Inspection

Walls and Partitions

• Check the condition of the plasterboard lining on internal partitions.
• Look for any signs of moisture ingress or dampness on the walls.

Floors

• Inspect the ground floor for any signs of damage or wear.
• Check the condition of the brown asphalt and felt underlay.

Ceilings

• Examine the plasterboard ceilings for any signs of cracking or damage.

Additional Considerations

• Assess the overall structural integrity of the property, paying particular attention to the PRC components.
• Check for any signs of timber decay, particularly in the timber fillets and battens.
• Evaluate the insulation and energy efficiency of the property, considering potential upgrades if necessary.

Typical Defects in KenKast Houses

Hairline Cracking

Hairline cracking between the PRC components is a common issue in KenKast houses. While minor cracks may not pose an immediate threat, they can indicate underlying structural problems that need to be addressed.

Moisture and Damp Issues

Moisture ingress and damp issues can arise if the damp-proof course (DPC) is compromised or if there are defects in the external render. These issues can lead to further structural damage and potential health hazards for occupants.

Timber Decay

Timber elements used in the construction, such as timber fillets and battens, are prone to decay if not properly treated or maintained. This can compromise the structural integrity of the property and pose safety risks.

Insulation and Energy Efficiency

KenKast houses may have inadequate insulation, leading to higher energy costs and a less comfortable living environment. Upgrading the insulation can improve energy efficiency and reduce heating costs.

Conclusion

KenKast houses represent an important chapter in the history of UK housing, offering a glimpse into the innovative construction methods of the 1960s. While these properties have their unique characteristics and charm, they also come with potential hazards and risks that need to be carefully considered by home buyers and investors.

When inspecting a KenKast house, it is crucial to pay close attention to the structural integrity of the PRC components, the condition of the timber elements, and the overall energy efficiency of the property. Addressing these issues can help ensure the long-term safety and comfort of the home.

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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