Overview of the Kingsthorne Special House

The Kingsthorne Special house, also known as the King’s Thorn, is a distinctive type of property that emerged in the mid-20th century. Designed and manufactured by D W Smith, these homes were primarily constructed in 1956. As an expert surveyor with extensive knowledge of system-built properties, I will provide a detailed examination of the Kingsthorne Special house, covering its construction, typical characteristics, potential hazards, and inspection tips.

Historical Context and Manufacturer

Period Built

The Kingsthorne Special houses were built in 1956, a period marked by a post-war housing boom in the UK. The need for rapid and cost-effective housing solutions led to the development of various system-built properties, including the Kingsthorne Special.

Manufacturer

D W Smith, a prominent name in the construction industry during the mid-20th century, was responsible for the design and manufacture of the Kingsthorne Special houses. Their expertise in prefabricated construction methods allowed for the efficient production of these homes.

Typical Characteristics of the Kingsthorne Special House

Identification Characteristics

The Kingsthorne Special houses are typically detached bungalows with a medium pitch gable roof covered with tiles. The external walls are rendered with Tyrolean finish and feature exposed Precast Reinforced Concrete (PRC) columns. These characteristics make the Kingsthorne Special easily identifiable among other property types.

Construction Details

Substructure

The substructure of the Kingsthorne Special house consists of concrete foundations, providing a stable base for the property.

External Walls

The external walls are constructed using a combination of materials:
– Render (Tyrolean): A textured finish applied to the exterior walls.
– Storey Height T-Section PRC Columns: These columns provide structural support.
– PRC Panels: Measuring 1 1/8″ x 21″ x 36″, these panels are used in the wall construction.
– Cavity: The walls feature a cavity for insulation purposes.
– Timber Noggins: These are used to provide additional support within the wall structure.
– Foil-Backed Hollow Core Plasterboard: Used for the internal wall finish.

Partitions

Internal partitions are typically constructed using timber stud walls, with a spine wall made of block for added stability.

Ground Floor

The specific construction details of the ground floor are not well-documented, but it is likely to be a solid concrete slab, common in properties of this era.

Ceilings

Ceilings in the Kingsthorne Special house are made of plasterboard, providing a smooth finish.

Roof

The roof structure consists of timber trusses, bituminous felt, and tiles, offering durability and weather resistance.

Typical Hazards and Risks

Structural Issues

One of the primary concerns with the Kingsthorne Special house is the potential for structural issues related to the PRC columns and panels. Over time, these components can deteriorate, leading to reduced structural integrity.

Corrosion of Steel Reinforcement

The steel reinforcement within the PRC columns and panels is susceptible to corrosion, particularly in areas with high moisture levels. This can compromise the strength of the structure and pose significant safety risks.

Carbonation

Carbonation is a chemical process that occurs when carbon dioxide penetrates the concrete, reducing its alkalinity and leading to the corrosion of steel reinforcement. This is a common issue in older concrete structures, including the Kingsthorne Special house.

Defective Premises Act

The Kingsthorne Special house is not specifically classified as defective under the Defective Premises Act. However, the potential structural issues and material degradation warrant careful inspection and assessment.

Inspection Tips for Surveyors

Visual Inspection

When inspecting a Kingsthorne Special house, start with a thorough visual inspection of the exterior and interior. Look for signs of cracking, spalling, or other damage to the PRC columns and panels.

Corrosion Assessment

Assess the extent of corrosion in the steel reinforcement by examining exposed areas and using non-destructive testing methods. Refer to the following resources for guidance:
– 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)

Structural Integrity

Evaluate the overall structural integrity of the property, paying close attention to any signs of movement or settlement. Check for uneven floors, misaligned doors and windows, and other indicators of structural issues.

Moisture Levels

Measure moisture levels in the walls and floors to identify potential areas of concern. High moisture levels can accelerate the corrosion of steel reinforcement and lead to other issues such as mould and damp.

Roof Condition

Inspect the roof for signs of damage or wear, including missing or broken tiles, deteriorated felt, and compromised timber trusses. Ensure that the roof is watertight and in good condition.

Typical Defects in the Kingsthorne Special House

PRC Column and Panel Deterioration

As mentioned earlier, the PRC columns and panels are prone to deterioration over time. This can manifest as cracking, spalling, and delamination, compromising the structural integrity of the property.

Corrosion of Steel Reinforcement

Corrosion of the steel reinforcement within the PRC components is a common defect. This can lead to reduced strength and stability, posing significant safety risks.

Carbonation

Carbonation of the concrete can reduce its alkalinity, leading to the corrosion of steel reinforcement. This is a gradual process that can significantly impact the longevity of the property.

Moisture Ingress

Moisture ingress can occur through the external walls, roof, and ground floor, leading to issues such as damp, mould, and timber decay. It is essential to address any sources of moisture to prevent further damage.

Roof Defects

The roof of the Kingsthorne Special house may suffer from various defects, including damaged tiles, deteriorated felt, and compromised timber trusses. Regular maintenance and timely repairs are crucial to ensure the roof remains in good condition.

Maintenance and Repair Recommendations

Addressing PRC Deterioration

To address PRC deterioration, consider the following steps:
– Repair or Replace Damaged Components: Replace severely damaged PRC columns and panels with new, structurally sound components.
– Apply Protective Coatings: Use protective coatings to prevent further deterioration and extend the lifespan of the PRC components.

Corrosion Mitigation

Mitigate corrosion of steel reinforcement by:
– Applying Corrosion Inhibitors: Use corrosion inhibitors to protect the steel reinforcement from further corrosion.
– Cathodic Protection: Implement cathodic protection systems to prevent corrosion of the steel reinforcement.

Carbonation Prevention

Prevent carbonation by:
– Applying Anti-Carbonation Coatings: Use anti-carbonation coatings to protect the concrete from carbon dioxide penetration.
– Regular Inspections: Conduct regular inspections to monitor carbonation levels and address any issues promptly.

Moisture Control

Control moisture levels by:
– Improving Drainage: Ensure proper drainage around the property to prevent water ingress.
– Repairing Leaks: Address any leaks in the roof, walls, or plumbing systems to prevent moisture ingress.
– Installing Damp-Proof Membranes: Use damp-proof membranes to protect the property from rising damp.

Roof Maintenance

Maintain the roof by:
– Regular Inspections: Conduct regular roof inspections to identify and address any issues promptly.
– Replacing Damaged Tiles: Replace any missing or broken tiles to maintain the roof’s integrity.
– Repairing Felt and Trusses: Repair or replace deteriorated felt and compromised timber trusses to ensure the roof remains watertight.

Conclusion

The Kingsthorne Special house, with its unique construction and historical significance, presents both opportunities and challenges for home buyers and investors. Understanding the typical characteristics, potential hazards, and common defects of this property type is essential for making informed decisions. By following the inspection tips and maintenance recommendations provided in this guide, you can ensure the longevity and safety of your Kingsthorne Special 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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