Historical Context and Manufacturing Background

The SSHA Wartime Cellular Concrete house, also known as the SSHA No-Fines house, is a unique piece of British architectural history. These properties were constructed during the 1940s, a period marked by significant housing shortages due to the Second World War. The Scottish Special Housing Association (SSHA) was the primary designer and manufacturer of these homes, aiming to provide quick and affordable housing solutions for the population.

The SSHA built approximately 100 of these houses, primarily in Scotland, although some examples can be found in other parts of the UK. The term “No-Fines” refers to the type of concrete used in construction, which lacks fine aggregates like sand, resulting in a porous, lightweight material. This type of concrete is also occasionally referred to as cellular concrete, although the naming conventions can be somewhat imprecise.

Architectural Characteristics and Design

Structural Overview

The SSHA Wartime Cellular Concrete houses are typically two-storey semi-detached or terraced properties. They feature a flat roof covered with bituminous felt, and the external walls are rendered throughout. The design was intended to be both functional and economical, addressing the urgent need for housing during and after the war.

Substructure

The substructure of these houses consists of concrete strip footings and brick under-building. A concrete slab forms the base, with a damp-proof course (DPC) integrated to prevent moisture ingress. This robust foundation was designed to provide stability and durability, essential for the quick construction methods employed during the wartime period.

External and Internal Walls

The external walls are constructed from 8-inch no-fines concrete, rendered to provide a weather-resistant finish. The separating walls between properties are also made from 8-inch no-fines concrete, ensuring sound insulation and structural integrity. Internal partitions are similarly constructed from no-fines concrete, contributing to the overall solidity of the building.

Floors and Ceilings

The ground floor is a concrete slab, providing a solid and durable base. The first floor is constructed from reinforced concrete (RC) slab, offering additional strength and stability. Ceilings are typically plastered, providing a smooth and clean finish.

Roof

The roof is a reinforced concrete slab covered with bituminous felt. This flat roof design was a common feature in many wartime and post-war houses, chosen for its simplicity and ease of construction. However, flat roofs can be prone to water pooling and leaks if not properly maintained.

Typical Hazards and Risks

Structural Concerns

One of the primary concerns with SSHA Wartime Cellular Concrete houses is the potential for structural issues. The no-fines concrete, while lightweight and easy to work with, can be prone to cracking and deterioration over time. This is particularly true if the concrete has been exposed to moisture, which can lead to corrosion of any embedded steel reinforcement.

Moisture Ingress

Moisture ingress is another significant risk, particularly given the flat roof design. Bituminous felt can degrade over time, leading to leaks and water damage. The damp-proof course (DPC) in the substructure is intended to prevent moisture from rising through the building, but if this fails, it can result in damp problems within the property.

Thermal Insulation

The no-fines concrete used in these houses has relatively poor thermal insulation properties. This can result in higher heating costs and potential issues with condensation and mould growth, particularly in poorly ventilated areas.

Asbestos

As with many properties built during the mid-20th century, there is a risk that asbestos-containing materials may have been used in the construction of SSHA Wartime Cellular Concrete houses. Asbestos was commonly used for its fire-resistant properties, but it poses significant health risks if disturbed.

Defective Premises Act Considerations

The Defective Premises Act 1972 imposes a duty on builders, developers, and landlords to ensure that properties are constructed and maintained to a reasonable standard. While the SSHA Wartime Cellular Concrete houses were built to address an urgent need for housing, they may not meet modern standards of construction and safety.

These properties are not automatically classed as defective under the Defective Premises Act. However, if significant structural issues, moisture ingress, or other hazards are identified, it may be possible to make a claim under the Act. It is essential to have a thorough survey conducted by a qualified professional to assess the condition of the property and identify any potential defects.

Inspection and Assessment Guide

External Inspection

When inspecting an SSHA Wartime Cellular Concrete house, start with a thorough external examination. Look for signs of cracking or deterioration in the rendered external walls. Pay particular attention to areas around windows and doors, as these can be points of weakness. Check the condition of the bituminous felt on the flat roof, looking for signs of wear, tear, or pooling water.

Internal Inspection

Inside the property, inspect the walls, floors, and ceilings for signs of damp or mould. Check for any cracks in the concrete, particularly in the first-floor RC slab. Ensure that the DPC is functioning correctly by looking for signs of rising damp on the ground floor.

Moisture and Thermal Performance

Use a moisture meter to check for elevated moisture levels in the walls and floors. Assess the thermal performance of the property, considering the potential for poor insulation in the no-fines concrete. Look for signs of condensation, particularly in corners and behind furniture.

Asbestos Survey

Given the age of the property, it is advisable to have an asbestos survey conducted. This should be carried out by a qualified professional who can identify any asbestos-containing materials and advise on the appropriate course of action if asbestos is found.

Typical Defects and Maintenance Tips

Cracking and Structural Movement

Cracking in the no-fines concrete is a common issue. Small hairline cracks may not be a cause for concern, but larger cracks or signs of structural movement should be investigated by a structural engineer. Regular monitoring and maintenance can help to prevent minor issues from becoming major problems.

Roof Maintenance

The flat roof covered with bituminous felt requires regular maintenance to prevent leaks. Inspect the roof at least once a year, looking for signs of wear or damage. Ensure that any repairs are carried out promptly to prevent water ingress.

Damp and Moisture Control

To prevent damp and moisture issues, ensure that the DPC is functioning correctly and that the property is well-ventilated. Use dehumidifiers if necessary, and consider installing additional insulation to improve thermal performance and reduce the risk of condensation.

Asbestos Management

If asbestos is identified in the property, it is essential to manage it safely. Asbestos-containing materials should not be disturbed, and any removal or remediation work should be carried out by a licensed professional. Regular monitoring and maintenance can help to ensure that asbestos does not pose a health risk.

Conclusion

The SSHA Wartime Cellular Concrete house is a fascinating example of mid-20th-century British architecture. While these properties were built to address an urgent need for housing during and after the Second World War, they may not meet modern standards of construction and safety. Potential buyers and investors should be aware of the typical hazards and risks associated with these properties, including structural concerns, moisture ingress, and the potential presence of asbestos.

A thorough survey conducted by a qualified professional is essential to assess the condition of an SSHA Wartime Cellular Concrete house and identify any potential defects. Regular maintenance and prompt repairs can help to ensure that these properties remain safe and habitable for years to come.

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.