Historical Context and Manufacturing Background

The Boyd Gibbons No-Fines house is a unique and intriguing property type that emerged in the 1940s. These houses were part of a broader movement in the UK to address the post-war housing shortage. Boyd Gibbons, the manufacturer, played a pivotal role in this era by introducing innovative construction techniques that were both cost-effective and efficient. With only 75 units built, these properties are relatively rare, making them a fascinating subject for home buyers and investors alike.

Design and Architectural Features

Typical Locations and Alternative Names

Boyd Gibbons No-Fines houses are predominantly found in suburban areas across the UK. They are also known simply as “No-Fines” houses, a name derived from the unique concrete mix used in their construction. These properties are typically two-storey semi-detached or detached houses, featuring a medium pitch hipped roof covered with concrete tiles. The external walls are rendered throughout, giving them a distinctive appearance.

Key Architectural Characteristics

One of the most notable features of Boyd Gibbons No-Fines houses is the flat-roofed ground floor bay and porch on the front elevation. This design element not only adds to the aesthetic appeal but also provides additional living space. The houses are constructed with a 10-inch no-fines reinforced concrete (RC) external wall, which is rendered for added durability and insulation.

Construction Details

Substructure

The substructure of Boyd Gibbons No-Fines houses consists of concrete strip footings and a concrete underbuilding. The brick-faced concrete slab provides a solid foundation, while a vertical damp-proof course (DPC) ensures protection against rising damp.

External Walls

The external walls are a defining feature of these houses. They are constructed from 10-inch no-fines reinforced concrete, which includes 1/2-inch square twisted mild steel (MS) bars over ground floor openings. These bars project beyond the reveals, providing additional structural support.

Separating Walls and Partitions

The separating walls between properties are also made from 10-inch no-fines concrete, ensuring robust sound insulation and fire resistance. Internal partitions are constructed from 4-inch clinker precast (PC) blocks, which are recessed into the external walls for added stability.

Floors

The ground floor is made of concrete, providing a durable and low-maintenance surface. The first floor consists of timber boarding on timber joists, which are notched over and skew-nailed to a timber wall plate. This wall plate is set on flat MS plates cast into the wall, ensuring a secure and stable structure.

Roof

The roof is constructed from timber trusses and covered with concrete tiles. This combination provides both strength and weather resistance, ensuring the longevity of the property.

Typical Hazards and Risks

Horizontal and Vertical Cracking

One of the most common issues with Boyd Gibbons No-Fines houses is horizontal and vertical cracking in the external walls. This is often due to the unique properties of the no-fines concrete, which can be more prone to cracking than traditional concrete mixes.

Inadequate Lateral Restraint

Another potential hazard is inadequate lateral restraint in the external walls. This can lead to structural instability, particularly in areas with high wind loads or seismic activity.

Low Cement Content

The no-fines concrete used in these houses has a very low cement content, which can result in friable (easily crumbled) concrete. This can compromise the structural integrity of the walls and may require remedial work to ensure the property remains safe and habitable.

Defective Premises Act Considerations

Boyd Gibbons No-Fines houses are not classified as defective under the Defective Premises Act. However, the unique construction methods and materials used in these properties mean that they may require more frequent maintenance and inspection than traditional houses. It is essential for potential buyers and investors to be aware of these considerations and to factor them into their decision-making process.

Inspection Guide for Surveyors

External Walls

When inspecting a Boyd Gibbons No-Fines house, surveyors should pay close attention to the external walls. Look for signs of horizontal and vertical cracking, as well as any areas where the concrete appears friable. It is also important to check for adequate lateral restraint, particularly in exposed locations.

Roof

Inspect the roof for any signs of damage or wear, particularly in the timber trusses and concrete tiles. Ensure that the roof is watertight and that there are no signs of leaks or water ingress.

Floors

Check the condition of the ground and first floors, looking for any signs of movement or instability. Pay particular attention to the timber joists on the first floor, ensuring that they are securely fixed to the wall plate.

Internal Partitions

Inspect the internal partitions for any signs of cracking or movement. Ensure that the clinker PC blocks are securely recessed into the external walls and that there are no signs of structural instability.

Typical Defects and Remedial Measures

Cracking in External Walls

Horizontal and vertical cracking in the external walls is a common issue with Boyd Gibbons No-Fines houses. This can often be addressed by applying a flexible render system, which can accommodate movement and prevent further cracking. In more severe cases, it may be necessary to install additional lateral restraint, such as wall ties or bracing.

Friable Concrete

The low cement content in the no-fines concrete can result in friable concrete, which may require remedial work to ensure the structural integrity of the walls. This can often be addressed by applying a cementitious coating or by injecting a resin-based consolidant into the affected areas.

Roof Repairs

The timber trusses and concrete tiles used in the roof construction can be prone to wear and damage over time. Regular inspection and maintenance are essential to ensure the roof remains watertight and structurally sound. In some cases, it may be necessary to replace damaged tiles or to reinforce the timber trusses.

Floor Stability

Ensuring the stability of the ground and first floors is crucial for the overall safety of the property. This may involve reinforcing the timber joists on the first floor or applying a self-levelling compound to the ground floor to address any movement or instability.

Conclusion

Boyd Gibbons No-Fines houses are a unique and fascinating property type that offers both challenges and opportunities for home buyers and investors. Understanding the construction methods and materials used in these properties is essential for making informed decisions and ensuring the long-term safety and stability of the house. By being aware of the typical hazards and risks, and by following a thorough inspection process, buyers and investors can make the most of these distinctive homes.

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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