The MFC House: A Comprehensive Guide for Home Buyers and Investors

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Overview of the MFC House

The MFC house, a product of the 1960s, represents a significant chapter in the history of British housing. These properties were primarily constructed by F C Precast Concrete Ltd and W Moss & Sons Ltd, with designs crafted by Miall Rhys-Davies & Partners and A MacDonald. Approximately 900 of these homes were built, and they are commonly found as bungalows and 2- and 3-storey terraced houses. The MFC house is also known by its alternative name, MFC Housing.

Identification Characteristics

Roof

MFC houses typically feature shallow or medium pitch gable or monopitch roofs covered with concrete tiles. This roofing style is not only distinctive but also functional, providing adequate drainage and durability.

External Walls

The front and rear external walls of MFC houses are constructed using storey-height precast concrete (PC) panels up to the first-floor level. Above this, the walls are clad with either tile hanging or aluminium sheets. The gable walls are made entirely of brick, which extends around the corners of the building, providing additional structural integrity and aesthetic appeal.

Construction Details

Substructure

The foundation of MFC houses is a concrete raft foundation, which includes a damp-proof membrane (DPM) to prevent moisture ingress.

External Walls

The front and rear walls consist of storey-height 3′ x 6 1/2″ PC panels with 1″ polystyrene cast-in for insulation. These panels are located on 3/4″ dowels and fixed to gable panels using 3/4″ stainless steel bolts with washers and cast-in sockets. Above the first floor, storey-height timber frame panels are sheathed externally with plywood and clad with tile hanging on timber battens. The internal lining is foil-backed plasterboard, with glass fibre insulation between the frame studs.

Gable Walls

The gable walls are clad with brick and have expanded polystyrene insulation in the cavity. Storey-height 5 1/2″ PC panels are bedded on dry pack and levelled on 1″ high-tensile steel dowel bars. A 4″ PC apex panel with fixing battens cast-in is used at the top, and a galvanised mild steel fire stop is installed at the first floor and eaves level.

Separating Walls

Separating walls are constructed using 7″ storey-height PC panels, bedded on dry pack and levelled on 1″ high-tensile steel dowel bars. These panels have rebates on each side at the first-floor level to house 7″ x 1 1/2″ bridging joists at alternate joist spacing.

Partitions

Loadbearing walls are made of storey-height PC panels, while non-loadbearing walls are constructed using Paramount partitions.

Floors

The ground floor is made of concrete, while the upper floors consist of chipboard on timber joists fixed to the gable wall with 1 1/4″ mild steel cramps turned over the wall and supported on mild steel lintels over openings in internal partitions.

Ceilings

Ceilings are typically made of plasterboard.

Roof

The roof structure includes timber trusses, PC purlins, and concrete tiles.

Typical Hazards and Risks

Structural Integrity

One of the primary concerns with MFC houses is the potential for structural issues, particularly related to the precast concrete panels. Over time, these panels can suffer from corrosion of the steel reinforcement, leading to cracking and spalling of the concrete. This can compromise the structural integrity of the building.

Insulation and Damp Issues

The insulation used in MFC houses, particularly the polystyrene cast-in panels, can degrade over time, leading to reduced thermal efficiency. Additionally, the damp-proof membrane (DPM) in the foundation can deteriorate, allowing moisture to penetrate the building and cause damp issues.

Fire Safety

The use of timber frame panels and glass fibre insulation in the construction of MFC houses can pose a fire risk. While the galvanised mild steel fire stops provide some protection, it is essential to ensure that these are in good condition and have not been compromised over time.

Asbestos

As with many properties built in the 1960s, there is a potential risk of asbestos being present in MFC houses. Asbestos was commonly used in building materials during this period, and its presence can pose significant health risks if disturbed.

Defective Premises Act

MFC houses are not specifically classed as defective under the Defective Premises Act. However, given the potential structural and safety issues associated with these properties, it is crucial to conduct a thorough survey and assessment before purchasing.

Inspection Guide for Surveyors

External Inspection

  1. Roof: Check the condition of the concrete tiles and the overall structure of the roof. Look for any signs of sagging, missing tiles, or damage to the timber trusses and PC purlins.
  2. Walls: Inspect the precast concrete panels for any signs of cracking, spalling, or corrosion of the steel reinforcement. Check the condition of the tile hanging or aluminium sheets above the first floor.
  3. Gable Walls: Examine the brickwork for any signs of deterioration or damage. Ensure that the expanded polystyrene insulation in the cavity is intact and effective.
  4. Foundation: Assess the condition of the concrete raft foundation and the damp-proof membrane (DPM). Look for any signs of moisture ingress or subsidence.

Internal Inspection

  1. Separating Walls: Check the condition of the 7″ storey-height PC panels and the bridging joists. Look for any signs of cracking or movement.
  2. Partitions: Inspect the loadbearing and non-loadbearing walls for any signs of damage or deterioration.
  3. Floors: Assess the condition of the concrete ground floor and the chipboard upper floors. Look for any signs of sagging, movement, or damage to the timber joists.
  4. Ceilings: Check the plasterboard ceilings for any signs of cracking or damage.
  5. Insulation: Ensure that the glass fibre insulation between the frame studs is intact and effective. Look for any signs of damp or mould.

Additional Considerations

  1. Fire Safety: Ensure that the galvanised mild steel fire stops are in good condition and have not been compromised. Check for any potential fire hazards, particularly in the timber frame panels and insulation.
  2. Asbestos: Conduct an asbestos survey to identify any potential asbestos-containing materials in the property. If asbestos is present, ensure that it is managed and removed safely by a qualified professional.

Typical Defects in MFC Houses

Corrosion of Steel Reinforcement

One of the most common defects in MFC houses is the corrosion of the steel reinforcement in the precast concrete panels. This can lead to cracking and spalling of the concrete, compromising the structural integrity of the building. Regular inspections and maintenance are essential to identify and address this issue promptly.

Damp and Insulation Issues

The insulation used in MFC houses, particularly the polystyrene cast-in panels, can degrade over time, leading to reduced thermal efficiency. Additionally, the damp-proof membrane (DPM) in the foundation can deteriorate, allowing moisture to penetrate the building and cause damp issues. It is crucial to address any damp problems promptly to prevent further damage and maintain a healthy living environment.

Fire Safety Concerns

The use of timber frame panels and glass fibre insulation in the construction of MFC houses can pose a fire risk. While the galvanised mild steel fire stops provide some protection, it is essential to ensure that these are in good condition and have not been compromised over time. Regular fire safety inspections and maintenance are crucial to mitigate this risk.

Asbestos

Asbestos was commonly used in building materials during the 1960s, and its presence in MFC houses can pose significant health risks if disturbed. It is essential to conduct an asbestos survey and manage any asbestos-containing materials safely to protect the health and safety of the occupants.

Variants of MFC Houses

While the typical MFC house features tile hanging on the front and rear first-floor external walls, some variants are clad with aluminium sheets. These variants may have different maintenance and inspection requirements, so it is essential to identify the specific construction details of the property being inspected.

References and Further Reading

For further information on the inspection and assessment of reinforced concrete durability, the following references are recommended:

  • 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)

These resources provide valuable guidance on identifying and addressing potential issues with the precast concrete panels used in MFC houses.

Conclusion

The MFC house represents a unique and significant chapter in the history of British housing. While these properties offer distinctive architectural features and historical value, they also come with potential risks and challenges. By understanding the typical characteristics, hazards, and inspection requirements of MFC houses, home buyers and investors can make informed decisions and ensure the long-term safety and integrity 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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