Introduction to the West’s 5M House

The West’s 5M house, a product of the 1960s, stands as a testament to the post-war era’s innovative approach to housing. Manufactured by West’s Piling & Construction Co. Ltd and designed by G H Wilkinson, these properties were part of a broader movement to address the housing shortage in the UK. As an expert surveyor, I will delve into the intricate details of these homes, providing you with a thorough understanding of their construction, typical characteristics, potential hazards, and inspection tips.

Historical Context and Manufacturing Details

Period and Location

The West’s 5M houses were predominantly built during the 1960s, a period marked by rapid urbanisation and a pressing need for affordable housing. These properties are typically found in suburban areas across the UK, where there was ample space for the development of detached bungalows.

Manufacturers and Designers

West’s Piling & Construction Co. Ltd, a prominent name in the construction industry during the mid-20th century, was responsible for the manufacturing of these homes. The design was spearheaded by G H Wilkinson, who aimed to create a cost-effective yet durable housing solution.

Typical Characteristics of the West’s 5M House

Architectural Features

The West’s 5M houses are easily identifiable by their distinct architectural features:

• Detached Bungalows: These properties are single-storey homes, offering a spacious and accessible living environment.
• Medium Pitch Gable Roof: The roofs are covered with interlocking concrete tiles, providing a robust and weather-resistant structure.
• External Walls: The walls are typically rendered with roughcast, giving the houses a textured and durable exterior.
• Horizontal Timber Boarding: The gable apex is adorned with horizontal timber boarding, adding a touch of rustic charm to the overall design.

Construction Details

Substructure

• Concrete Strip Footings: The foundation consists of concrete strip footings, ensuring stability and support for the structure.
• PRC Ground Beams: The ground beams are made of pre-cast reinforced concrete (PRC), featuring cast-in anchorages for wall panels and projecting tie reinforcement.
• Concrete Slab: The ground floor is constructed with a concrete slab, providing a solid base for the property.
• Damp Proof Course (DPC): A DPC is installed to prevent moisture from rising through the structure.

External Walls

• Rendered Panels: The external walls are made of storey-height pre-cast concrete panels, rendered for added protection and aesthetic appeal.
• Galvanised MS Bolts: The panels are fixed together using galvanised mild steel bolts, ensuring a secure and durable connection.
• Butyl Mastic Sealing Strip: A butyl mastic sealing strip is used to seal the joints between panels, preventing water ingress.
• Insulspan Chipboard Lining: The internal lining of the walls is made of Insulspan chipboard, providing insulation and a smooth finish.

Roof

• Timber Trusses: The roof structure is supported by timber trusses, offering strength and stability.
• Concrete Tiles: The roof is covered with interlocking concrete tiles, providing a weather-resistant and durable covering.

Partitions and Ceilings

• Timber Stud Partitions: Internal partitions are constructed with timber studs, lined with plasterboard for a smooth finish.
• Plasterboard Ceilings: The ceilings are made of plasterboard, offering a clean and even surface.

Typical Hazards and Risks

Structural Concerns

One of the primary concerns with the West’s 5M houses is the potential for structural issues, particularly related to the pre-cast reinforced concrete (PRC) components. Over time, PRC can suffer from corrosion of the steel reinforcement, leading to weakening and potential failure of the structural elements.

Moisture Ingress

The use of butyl mastic sealing strips, while effective initially, can deteriorate over time, leading to gaps and potential water ingress. This can result in damp issues, which can affect the structural integrity and indoor air quality.

Insulation and Energy Efficiency

The insulation provided by the Insulspan chipboard lining may not meet modern energy efficiency standards. Homeowners may need to consider additional insulation measures to improve thermal performance and reduce energy costs.

Asbestos

Given the era of construction, there is a possibility that asbestos-containing materials were used in some components, such as insulation or ceiling tiles. Asbestos poses significant health risks if disturbed, so it is crucial to conduct a thorough survey to identify and manage any asbestos-containing materials.

Defective Premises Act and Classification

The West’s 5M houses are not typically classified as defective under the Defective Premises Act. However, it is essential to conduct a detailed survey to assess the condition of the property and identify any potential issues that may require remediation.

Inspection Tips for Surveyors

Structural Assessment

• Check for Corrosion: Inspect the PRC components for signs of corrosion, such as rust stains or spalling concrete. Use a cover meter to detect the depth of the steel reinforcement and assess its condition.
• Examine Joints: Check the condition of the butyl mastic sealing strips and look for any gaps or signs of deterioration. Ensure that the joints between panels are secure and free from movement.

Moisture and Dampness

• Inspect for Damp: Use a moisture meter to check for signs of dampness in the walls and floors. Pay particular attention to areas around windows, doors, and joints between panels.
• Check DPC: Ensure that the damp proof course is intact and functioning correctly. Look for any signs of rising damp or moisture ingress.

Insulation and Energy Efficiency

• Assess Insulation: Check the condition of the Insulspan chipboard lining and consider the need for additional insulation. Use a thermal imaging camera to identify any areas of heat loss.
• Evaluate Windows and Doors: Inspect the windows and doors for draughts and consider upgrading to double or triple glazing to improve energy efficiency.

Asbestos Survey

• Conduct an Asbestos Survey: Engage a qualified asbestos surveyor to conduct a thorough survey of the property. Identify any asbestos-containing materials and develop a management plan to address any risks.

Typical Defects in West’s 5M Houses

Corrosion of Steel Reinforcement

As mentioned earlier, the corrosion of steel reinforcement in PRC components is a common issue. This can lead to spalling concrete, cracks, and ultimately, structural failure if not addressed promptly.

Deterioration of Sealing Strips

The butyl mastic sealing strips used to seal the joints between panels can deteriorate over time, leading to gaps and potential water ingress. Regular inspection and maintenance are essential to prevent moisture-related issues.

Thermal Bridging

The use of pre-cast concrete panels can result in thermal bridging, where heat is conducted through the structure, leading to heat loss and reduced energy efficiency. Additional insulation measures may be required to address this issue.

Damp and Mould

Moisture ingress, whether through deteriorated sealing strips or other means, can lead to damp and mould issues. This not only affects the structural integrity but also poses health risks to occupants.

Asbestos-Related Issues

If asbestos-containing materials are present, they can pose significant health risks if disturbed. It is crucial to identify and manage any asbestos-containing materials to ensure the safety of occupants.

Guidance on Inspection and Assessment

Reinforced Concrete Durability

For a comprehensive assessment of reinforced concrete durability, refer to the following resources:

• Corrosion of Steel in Concrete (BRE Digest 444, Pts 1–3): This publication provides detailed guidance on the causes, effects, and prevention of steel corrosion in concrete.
• Repair and Maintenance of Reinforced Concrete (BR 254): This guide offers practical advice on the repair and maintenance of reinforced concrete structures.
• Carbonation Depths in Structural-Quality Concrete (BR 19): This publication discusses the effects of carbonation on concrete and provides methods for assessing carbonation depths.

Conclusion

The West’s 5M house, with its unique construction and historical significance, offers a fascinating glimpse into the post-war housing boom in the UK. While these properties have their share of potential hazards and risks, a thorough understanding of their construction and careful inspection can help mitigate these issues. As a home buyer or investor, being aware of the typical characteristics, common defects, and inspection tips can empower you to make informed decisions and 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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