Historical Context and Manufacturing Background

The Hamish Cross Type 1 house is a notable example of early 20th-century British architecture, specifically designed to address the housing shortages that arose during and after World War I. These properties were constructed between 1915 and the 1940s, a period marked by rapid urbanisation and the need for affordable, quickly-built homes. The primary manufacturers of these houses were Abdon Clee and Stobe Quarry, with the design spearheaded by the innovative architect Hamish Cross.

These houses are predominantly found in suburban areas across the UK, particularly in regions that experienced significant population growth during the early 20th century. The Hamish Cross Type 1 house is also known by several alternative names, reflecting its widespread adoption and slight regional variations.

Identification Characteristics

Exterior Features

The Hamish Cross Type 1 house is typically a two-storey detached property, easily identifiable by its shallow pitch hipped roof covered with slates. The external walls are constructed using Precast Reinforced Concrete (PRC) columns with integral corbels at the eaves level, infilled with PRC panels. This construction method was chosen for its cost-effectiveness and speed of assembly.

One of the distinctive features of these houses is the ground-level PRC sill and the chimney stack, which is also formed with PRC columns and infill panels. The windows are usually metal-framed, and the gutters are made from asbestos cement, a common material used during that era.

Interior Features

Internally, the Hamish Cross Type 1 house features concrete floors on both the ground and first levels. The ground floor is a solid concrete slab, while the first floor consists of coffered reinforced concrete (RC) floor slabs supported by RC beams and intermediate exposed PRC columns with splayed heads. The partitions within the house are made from PC columns with splayed heads and recessed concrete panels.

Construction Details

Substructure

The substructure of the Hamish Cross Type 1 house consists of concrete strip footings, which provide a stable foundation for the property. Between the columns, clinker concrete underbuilding is used, adding to the structural integrity of the house. The concrete slab forms the base of the ground floor, ensuring durability and resistance to moisture ingress.

External Walls

The external walls are a key feature of the Hamish Cross Type 1 house. They are constructed using 6-inch eaves height PRC columns and 10-inch by 10-inch PRC corner columns placed directly on the strip foundations. The walls are infilled with dense PRC panels measuring 18 inches by 36 inches by 1 3/4 inches, creating a cavity that enhances the thermal insulation of the property. Additionally, clinker PRC panels of the same dimensions are used, contributing to the overall robustness of the structure.

Roof

The roof of the Hamish Cross Type 1 house is characterised by its shallow pitch and hipped design, covered with slates and clay hip tiles. This design not only provides an aesthetically pleasing appearance but also ensures effective water drainage, reducing the risk of leaks and water damage.

Typical Hazards and Risks

Cracking and Spalling of PRC Components

One of the most common issues with the Hamish Cross Type 1 house is the cracking and spalling of the external PRC components. Over time, the concrete can deteriorate due to exposure to the elements, leading to cracks and the eventual spalling (breaking away) of the material. This can compromise the structural integrity of the house and may require significant repairs.

Asbestos Concerns

The use of asbestos cement gutters poses a health risk, as asbestos fibres can become airborne if the material is disturbed or damaged. It is essential to have these components inspected and, if necessary, replaced by a qualified professional to ensure the safety of the occupants.

Metal Window Frames

The metal window frames, while durable, can be prone to rust and corrosion, particularly in areas with high humidity or salt air. Regular maintenance and timely repairs are crucial to prevent these issues from escalating.

Defective Premises Act Considerations

The Hamish Cross Type 1 house is not classified as defective under the Defective Premises Act. However, due to the age and construction methods used, it is essential to conduct thorough inspections and address any identified issues promptly. This will ensure the property remains safe and habitable for its occupants.

Inspection Guide for Surveyors

External Inspection

1. Roof: Check for any missing or damaged slates and clay hip tiles. Inspect the overall condition of the roof structure, paying particular attention to any signs of sagging or water ingress.
2. Walls: Examine the PRC columns and panels for any signs of cracking, spalling, or other damage. Look for any areas where the concrete may be deteriorating or where the infill panels are coming loose.
3. Chimney Stack: Inspect the chimney stack for any signs of damage or instability. Ensure that the PRC columns and infill panels are intact and free from significant cracks.
4. Gutters: Check the asbestos cement gutters for any signs of damage or wear. If asbestos is present, ensure that it is handled and disposed of safely by a qualified professional.
5. Windows: Inspect the metal window frames for any signs of rust or corrosion. Ensure that the windows open and close properly and that the seals are intact.

Internal Inspection

1. Floors: Examine the concrete floors for any signs of cracking or unevenness. Check for any areas where the concrete may be deteriorating or where there is evidence of moisture ingress.
2. Partitions: Inspect the PC columns and recessed concrete panels for any signs of damage or instability. Ensure that the partitions are securely in place and free from significant cracks.
3. Ceilings: While the specific construction details of the ceilings are not known, it is essential to check for any signs of sagging, water damage, or other issues that may indicate structural problems.

Typical Defects and Maintenance Tips

Cracking and Spalling

To address cracking and spalling of the PRC components, it is essential to carry out regular inspections and repairs. Small cracks can be filled with appropriate sealants, while more significant damage may require the replacement of the affected panels. It is crucial to use materials that are compatible with the original construction to ensure the longevity of the repairs.

Asbestos Management

If asbestos cement gutters are present, it is vital to have them inspected by a qualified professional. If the asbestos is in good condition and not disturbed, it may not pose an immediate risk. However, if the material is damaged or deteriorating, it should be safely removed and replaced with modern, non-hazardous alternatives.

Window Maintenance

Regular maintenance of the metal window frames is essential to prevent rust and corrosion. This includes cleaning the frames, applying rust inhibitors, and repainting as necessary. If the frames are severely corroded, they may need to be replaced to ensure the windows remain functional and secure.

Conclusion

The Hamish Cross Type 1 house is a significant example of early 20th-century British architecture, designed to address the housing needs of a rapidly growing population. While these properties offer a unique charm and historical value, they also come with specific challenges and maintenance requirements.

By understanding the typical characteristics, construction details, and potential hazards associated with the Hamish Cross Type 1 house, home buyers and investors can make informed decisions and ensure the long-term safety and stability of their investment. Regular inspections and timely repairs are crucial to maintaining the structural integrity and habitability of these properties.

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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