Overview of the Hardy House

The Hardy House, a notable example of early 20th-century British architecture, stands as a testament to the innovative construction techniques of its time. Designed and manufactured by T E Hardy in the 1920s, these properties are primarily found in suburban areas across the UK. Known for their distinctive two-storey design and rendered external walls, Hardy Houses have both historical significance and unique structural characteristics that potential buyers and investors should be aware of.

Historical Context and Manufacturing

The Era of Construction

The Hardy House was constructed during the 1920s, a period marked by a post-World War I housing boom. This era saw a significant demand for affordable and quickly constructed homes, leading to the development of various system-built properties. The Hardy House was one such innovation, designed to meet the needs of a growing population.

The Manufacturer: T E Hardy

T E Hardy, the manufacturer behind these homes, was a prominent figure in the construction industry during the early 20th century. Known for their expertise in pre-cast concrete (PC) technology, T E Hardy’s designs were both practical and forward-thinking. The use of PC blocks and reinforced concrete elements was a hallmark of their construction approach, aimed at providing durable and cost-effective housing solutions.

Identifying Characteristics of Hardy Houses

External Features

Hardy Houses are easily identifiable by their two-storey structure and rendered external walls. The rendering is typically roughcast, giving the exterior a textured appearance. These homes often feature PC blocks throughout, contributing to their robust and solid look.

Internal Features

Internally, Hardy Houses were designed with practicality in mind. The first floor typically consists of timber boarding on timber joists, while the ground floor construction details are less well-documented. The internal partitions and separating walls are also not well-known, which can pose challenges during inspections and renovations.

Construction Details

Substructure

The substructure of Hardy Houses remains largely undocumented, which can be a point of concern for potential buyers. Without detailed information on the foundations, it is crucial to conduct thorough inspections to ensure structural integrity.

Frame

The main frame of Hardy Houses consists of double pre-cast reinforced concrete (PRC) columns tied with galvanised iron plates. PRC beams are bolted through mild steel (MS) brackets to the inner column projections. This construction method provides a sturdy framework but also introduces potential points of weakness, particularly where metal components are involved.

External Walls

The external walls are constructed using rendered PC blocks, with a cavity and clinker PC blocks. Wall ties, both metal and other types, are used to secure the structure. The use of PC blocks and wall ties is a significant feature, contributing to the overall durability of the property.

Roof

Details about the roof construction of Hardy Houses are not well-documented. However, given the era of construction, it is likely that traditional roofing materials such as slate or tile were used. Modern inspections should focus on the condition of the roofing materials and any potential issues with water ingress or structural damage.

Floors

The first floor of Hardy Houses is typically made of timber boarding on timber joists. In some variants, the first floor may be constructed of concrete. The ground floor construction details are not well-known, which necessitates careful inspection to identify any potential issues.

Typical Defects and Hazards

Corrosion of Steel in Concrete

One of the primary concerns with Hardy Houses is the potential for corrosion of steel reinforcements within the concrete. This can lead to structural weaknesses and, in severe cases, compromise the integrity of the entire building. Guidance on inspecting and assessing reinforced concrete durability can be found in BRE Digest 444 (Parts 1-3) and other related publications.

Carbonation of Concrete

Carbonation is a process where carbon dioxide from the air penetrates the concrete and reacts with calcium hydroxide to form calcium carbonate. This can reduce the alkalinity of the concrete, leading to corrosion of the steel reinforcements. Assessing carbonation depths in structural-quality concrete is crucial for maintaining the longevity of Hardy Houses.

Wall Tie Failure

The metal wall ties used in Hardy Houses can corrode over time, leading to potential structural issues. Regular inspections should focus on the condition of these ties and any signs of failure, such as cracking or bulging of the external walls.

Render Deterioration

The roughcast render on the external walls can deteriorate over time, leading to potential water ingress and damage to the underlying PC blocks. Inspecting the condition of the render and addressing any issues promptly is essential for maintaining the property’s integrity.

Inspection and Maintenance Tips

Visual Inspection

A thorough visual inspection is the first step in assessing the condition of a Hardy House. Look for signs of cracking, bulging, or other structural issues in the external walls. Pay particular attention to areas around windows and doors, where movement and stress are often concentrated.

Structural Assessment

Engage a qualified surveyor to conduct a detailed structural assessment. This should include checking the condition of the PRC columns, beams, and wall ties. The surveyor should also assess the depth of carbonation in the concrete and the condition of any steel reinforcements.

Roof Inspection

Inspect the roof for any signs of damage or wear. Check for missing or broken tiles, and ensure that the roof structure is sound. Pay attention to any signs of water ingress, which can lead to significant damage if not addressed promptly.

Render Maintenance

Regular maintenance of the external render is crucial for preventing water ingress and protecting the underlying PC blocks. Address any cracks or areas of deterioration promptly, and consider applying a protective coating to extend the life of the render.

Wall Tie Replacement

If wall tie failure is identified, it is essential to replace the affected ties promptly. This is a specialist task that should be carried out by a qualified contractor to ensure the structural integrity of the property is maintained.

Legal Considerations

Defective Premises Act

The Hardy House is not specifically classed as defective under the Defective Premises Act. However, given the potential issues with corrosion and wall tie failure, it is essential to conduct thorough inspections and address any identified defects promptly. Failure to do so could result in legal liabilities for property owners.

Building Regulations

When carrying out any repairs or renovations on a Hardy House, it is crucial to comply with current building regulations. This includes ensuring that any structural work is carried out by qualified professionals and that all materials used meet the required standards.

Conclusion

The Hardy House, with its distinctive design and historical significance, offers a unique opportunity for home buyers and investors. However, it is essential to be aware of the potential structural issues and maintenance requirements associated with these properties. By conducting thorough inspections and addressing any identified defects promptly, 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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