Understanding the BCCF House

The British Cast Concrete Federation (BCCF) house, also known as the BCCF Temporary Bungalow, British Cast Concrete Federation Croft, or Granite Prefab, is a unique property type that emerged in the 1940s. These homes were part of the post-war housing boom, designed to address the urgent need for affordable and quickly constructed housing. As an expert surveyor, I will guide you through the essential aspects of these properties, from their construction characteristics to potential hazards and inspection tips.

Historical Context and Manufacturers

Period Built and Typical Locations

The BCCF houses were predominantly built in the 1940s, a period marked by a significant housing shortage following World War II. These homes were primarily constructed in urban and suburban areas across the UK, where the demand for quick and affordable housing was most acute. The British Cast Concrete Federation, a key player in the construction industry at the time, was responsible for the design and manufacture of these properties.

Design and Construction

The BCCF houses were designed as both bungalows and two-storey semi-detached houses. They featured a medium pitch hipped or gable roof covered with clay or concrete tiles. The external walls were typically rendered throughout or constructed with Precast Reinforced Concrete (PRC) columns and panels. Some bungalows also had a gable apex with tile hanging, adding a distinctive architectural feature.

Typical Characteristics and Identification

External Features

• Roof: Medium pitch hipped or gable roof covered with clay or concrete tiles.
• Walls: Rendered throughout or constructed with PRC columns and panels.
• Gable Apex: Tile hanging on bungalows.
• Front Door Hoods: Precast concrete (PC) front door hoods.
• Corner Columns: Dished corner columns, with some encased in brick.

Internal Features

• Substructure: Concrete strip footings, PRC ground sill units, concrete slab, and Damp Proof Course (DPC).
• External Walls: Eaves height T-section PRC columns with vertical slots and non-ferrous bars, PRC corner columns, PRC perimeter beams, PC panels with flanges and inclined slots, cavity, clinker PC blocks, PC eaves units, lightweight PRC boot lintel, and PC perimeter beams.
• Separating Wall: Clinker aggregate concrete cavity wall.
• Partitions: Clinker PC blocks.
• Ground Floor: Concrete.
• First Floor: Timber joists on PRC beam, RSA bolted to floor joists.
• Ceilings: Plasterboard.
• Roof: Timber rafters, concrete tiles.

Variants

• Corner PRC Columns: Some encased in brickwork.
• External Walls: Rendered throughout.
• Wall Linings and Partitions: Foamed slag aggregate PC blocks or woodwool slabs.
• Ground Floor: Suspended timber.
• Roof Cover: Clay tiles, with tile hanging to gable apex.

Potential Hazards and Risks

Structural Concerns

One of the primary concerns with BCCF houses is the durability of the reinforced concrete used in their construction. Over time, the steel reinforcement within the concrete can corrode, leading to structural weaknesses. This is particularly problematic in properties that have not been adequately maintained or where the concrete has been exposed to moisture.

Common Defects

• Corrosion of Steel Reinforcement: This can lead to cracking and spalling of the concrete, compromising the structural integrity of the property.
• Carbonation: The process by which carbon dioxide from the air penetrates the concrete and reacts with the calcium hydroxide to form calcium carbonate. This can reduce the alkalinity of the concrete, leading to corrosion of the steel reinforcement.
• Concrete Deterioration: General wear and tear, exposure to the elements, and lack of maintenance can all contribute to the deterioration of the concrete.

Defective Premises Act

The BCCF houses are not typically classified as defective under the Defective Premises Act. However, due to the potential structural issues associated with the use of reinforced concrete, it is crucial for prospective buyers and investors to conduct thorough inspections and assessments before purchasing these properties.

Inspection and Assessment Tips

Guidance for Surveyors

When inspecting a BCCF house, it is essential to follow the guidance provided in the following documents:

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

Step-by-Step Inspection Process

1. External Inspection:
2. Examine the roof for any signs of damage or wear, particularly focusing on the tiles and the overall structure.
3. Inspect the external walls for cracks, spalling, or any signs of concrete deterioration.

4. Check the condition of the front door hoods and corner columns, noting any encasement in brickwork.

5. Internal Inspection:

6. Assess the condition of the substructure, including the concrete strip footings, PRC ground sill units, and concrete slab.
7. Inspect the external walls from the inside, looking for any signs of moisture ingress or structural weaknesses.
8. Examine the separating wall and partitions for any cracks or signs of deterioration.
9. Check the ground and first floors for any unevenness or structural issues.

10. Inspect the ceilings and roof structure, paying particular attention to the timber rafters and concrete tiles.

11. Specialist Testing:

12. Conduct tests to measure the carbonation depth in the concrete.
13. Use non-destructive testing methods to assess the condition of the steel reinforcement within the concrete.
14. Consider employing a structural engineer to provide a detailed assessment of the property’s overall condition.

Typical Construction Details

Substructure

The substructure of a BCCF house typically consists of concrete strip footings, PRC ground sill units, a concrete slab, and a Damp Proof Course (DPC). These elements provide the foundation and support for the rest of the structure.

External Walls

The external walls are constructed using eaves height T-section PRC columns with vertical slots and non-ferrous bars, PRC corner columns, PRC perimeter beams, PC panels with flanges and inclined slots, a cavity, clinker PC blocks, PC eaves units, lightweight PRC boot lintel, and PC perimeter beams. This combination of materials and construction techniques provides the necessary strength and durability for the property.

Separating Wall

The separating wall between properties is typically constructed using clinker aggregate concrete cavity wall. This provides both structural support and sound insulation between adjoining properties.

Partitions

Internal partitions are usually made from clinker PC blocks, providing a lightweight yet durable solution for dividing internal spaces.

Floors

The ground floor is typically constructed from concrete, providing a solid and durable base. The first floor is usually made from timber joists on a PRC beam, with RSA bolted to the floor joists for additional support.

Ceilings and Roof

Ceilings are typically made from plasterboard, providing a smooth and easily finished surface. The roof structure consists of timber rafters covered with concrete tiles, providing both strength and weather resistance.

Common Defects in BCCF Houses

Corrosion of Steel Reinforcement

As mentioned earlier, one of the most common defects in BCCF houses is the corrosion of the steel reinforcement within the concrete. This can lead to cracking and spalling of the concrete, compromising the structural integrity of the property.

Carbonation

Carbonation is another common issue in BCCF houses. This process reduces the alkalinity of the concrete, leading to corrosion of the steel reinforcement. It is essential to measure the carbonation depth and take appropriate remedial action if necessary.

Concrete Deterioration

General wear and tear, exposure to the elements, and lack of maintenance can all contribute to the deterioration of the concrete. Regular inspections and maintenance are crucial to ensure the longevity and safety of the property.

Moisture Ingress

Moisture ingress can lead to a range of issues, including the deterioration of the concrete, corrosion of the steel reinforcement, and the growth of mould and mildew. It is essential to address any signs of moisture ingress promptly to prevent further damage.

Maintenance and Repair Tips

Regular Inspections

Conducting regular inspections is crucial to identify and address any potential issues before they become significant problems. This includes both external and internal inspections, as well as specialist testing to assess the condition of the steel reinforcement and the carbonation depth in the concrete.

Addressing Corrosion

If corrosion of the steel reinforcement is identified, it is essential to take appropriate remedial action. This may include removing and replacing the affected concrete, applying corrosion inhibitors, or using cathodic protection to prevent further corrosion.

Repairing Concrete

Any cracks or spalling in the concrete should be repaired promptly to prevent further deterioration. This may involve patching the affected areas, applying a protective coating, or using specialist repair techniques to restore the integrity of the concrete.

Preventing Moisture Ingress

Addressing any signs of moisture ingress is crucial to prevent further damage. This may involve repairing or replacing damaged DPC, sealing any cracks or gaps in the external walls, and ensuring that the roof and gutters are in good condition to prevent water from entering the property.

Conclusion

The BCCF house is a unique and historically significant property type that offers both opportunities and challenges for home buyers and investors. Understanding the typical characteristics, potential hazards, and common defects associated with these properties is crucial to making an informed decision. By conducting thorough inspections and regular maintenance, you can ensure the longevity and safety of your 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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