Historical Context and Background

The Span Type K house, a distinctive architectural style, emerged during a transformative period in British housing history. Designed by the renowned architect Eric Lyons and manufactured by Span Developments Ltd, these homes were constructed between 1967 and 1969. A total of 341 units were built, primarily located in suburban areas across the UK. These properties are also known simply as “Span” houses.

Span Developments Ltd, under the visionary leadership of Eric Lyons, aimed to create modern, community-focused housing that combined aesthetic appeal with practical living spaces. The Span Type K house is a testament to this vision, offering a unique blend of architectural innovation and functional design.

Identification Characteristics

Span Type K houses are easily identifiable by their distinctive architectural features. These properties include terraced bungalows and two- and three-storey terraced houses. One of the most notable features is the shallow pitch monopitch roof or the double monopitch roof of sawtooth section, covered with asbestos cement slates. The external walls are constructed from a variety of materials, including brick, painted asbestos cement sheet, asbestos cement slate hanging, or painted vertical timber boarding on the first floor level. The upper floors often feature stained vertical timber boarding or asbestos cement slate hanging.

Most dwellings have a single-storey entrance porch clad in stained vertical timber boarding with a flat roof. Additionally, some properties include single-storey rear extensions with flat or monopitch roofs. The separating walls between properties are typically constructed from painted asbestos cement sheet panels, while the gable walls are made entirely of brick.

Typical Construction Details

Roof

The roofs of Span Type K houses are a defining feature. They are either shallow pitch monopitch roofs or double monopitch roofs with a sawtooth section. These roofs are covered with asbestos cement slates, which were a common roofing material during the period of construction. The use of asbestos cement slates provided durability and weather resistance, although it also introduced potential health hazards, which we will discuss later.

Walls

The external walls of Span Type K houses are constructed using a combination of materials. The front and rear walls are typically timber frame panels clad with asbestos cement, brick, vertical timber boarding, or asbestos cement slate hanging on the first floor level. The upper floors often feature stained vertical timber boarding or asbestos cement slate hanging. The gable walls are constructed from brick, cavity, and blockwork, providing structural stability and insulation.

Floors

The ground floors of Span Type K houses are made of concrete, offering a solid and durable foundation. The first floors are constructed from timber panels, which provide flexibility and ease of construction. The ceilings are lined with plasterboard, which is a common material used for its fire-resistant properties and ease of finishing.

Main Frame

The main frame of Span Type K houses consists of coupled RS A-frames placed centrally on the plan. These frames provide structural support and stability to the overall construction. The protective coating used on the frames is not known, but it is essential to ensure that the frames are adequately protected from corrosion and other potential damage.

Typical Hazards and Risks

Asbestos

One of the most significant hazards associated with Span Type K houses is the presence of asbestos. Asbestos cement slates were commonly used for roofing and cladding during the period of construction. While asbestos provided durability and weather resistance, it poses serious health risks if disturbed. Asbestos fibres, when inhaled, can cause severe respiratory diseases, including asbestosis, lung cancer, and mesothelioma. It is crucial to handle asbestos-containing materials with care and seek professional assistance for removal or encapsulation.

Structural Integrity

The structural integrity of Span Type K houses can be compromised over time due to various factors, including weathering, wear and tear, and lack of maintenance. It is essential to conduct regular inspections to identify any signs of structural damage, such as cracks in the walls, sagging roofs, or deteriorating timber frames. Addressing these issues promptly can prevent further damage and ensure the safety and longevity of the property.

Moisture and Dampness

Moisture and dampness are common issues in older properties, including Span Type K houses. The use of timber frame panels and other materials susceptible to moisture can lead to dampness, mould growth, and rot. It is crucial to ensure proper ventilation, adequate drainage, and regular maintenance to prevent moisture-related problems. Conducting a thorough inspection for signs of dampness, such as water stains, musty odours, or peeling paint, can help identify and address these issues early on.

Defective Premises Act

The Span Type K house is not classified as defective under the Defective Premises Act. However, it is essential to be aware of the potential hazards and risks associated with these properties. Conducting a thorough inspection and assessment by a qualified surveyor can help identify any issues and ensure that the property meets the required safety standards.

Inspection and Assessment Guide

When inspecting a Span Type K house, it is crucial to follow a systematic approach to identify any potential issues and assess the overall condition of the property. Here is a step-by-step guide to help you conduct a comprehensive inspection:

Exterior Inspection

1. Roof: Examine the roof for any signs of damage, such as missing or broken asbestos cement slates, sagging, or leaks. Check the condition of the gutters and downpipes to ensure proper drainage.

2. Walls: Inspect the external walls for cracks, bulging, or signs of deterioration. Pay close attention to the cladding materials, such as asbestos cement sheets, brick, and timber boarding. Look for any signs of moisture ingress or rot.

3. Windows and Doors: Check the condition of the windows and doors, including the frames, glazing, and seals. Look for any signs of damage, such as rot, warping, or broken glass. Ensure that the windows and doors open and close properly.

4. Porch and Extensions: Inspect the single-storey entrance porch and any rear extensions for signs of damage or deterioration. Check the condition of the flat or monopitch roofs and the cladding materials.

Interior Inspection

1. Walls and Ceilings: Examine the internal walls and ceilings for cracks, dampness, or signs of structural movement. Pay close attention to the separating walls, which are typically constructed from painted asbestos cement sheet panels.

2. Floors: Inspect the ground and first floors for any signs of damage, such as cracks, unevenness, or sagging. Check the condition of the timber panels and concrete floors.

3. Timber Frame: Assess the condition of the timber frame, including the coupled RS A-frames. Look for any signs of rot, insect infestation, or structural damage. Ensure that the frames are adequately protected from moisture and other potential hazards.

4. Plumbing and Electrical Systems: Check the plumbing and electrical systems for any signs of leaks, corrosion, or outdated components. Ensure that the systems are in good working order and meet the required safety standards.

Asbestos Assessment

1. Identification: Identify any asbestos-containing materials, such as asbestos cement slates, sheets, or cladding. It is essential to handle these materials with care and avoid disturbing them.

2. Condition Assessment: Assess the condition of the asbestos-containing materials. Look for any signs of damage, such as cracks, breaks, or deterioration. If the materials are in good condition, they can be left undisturbed. However, if they are damaged or deteriorating, it is crucial to seek professional assistance for removal or encapsulation.

3. Professional Assistance: If you suspect the presence of asbestos or need to remove or encapsulate asbestos-containing materials, it is essential to seek professional assistance from a qualified asbestos removal contractor. They have the expertise and equipment to handle asbestos safely and comply with the necessary regulations.

Typical Defects Common in Span Type K Houses

Roof Defects

1. Asbestos Cement Slates: Over time, asbestos cement slates can become brittle and prone to cracking or breaking. This can lead to leaks and water ingress, causing damage to the underlying structure. Regular inspections and maintenance are essential to identify and address any issues with the roof.

2. Sagging Roofs: The shallow pitch monopitch roofs or double monopitch roofs of Span Type K houses can be susceptible to sagging over time. This can be caused by structural movement, inadequate support, or deterioration of the timber frame. It is crucial to address any signs of sagging promptly to prevent further damage.

Wall Defects

1. Cracks and Bulging: The external walls of Span Type K houses can develop cracks or bulging due to structural movement, weathering, or inadequate construction. These defects can compromise the structural integrity of the property and should be addressed promptly.

2. Moisture Ingress: The use of timber frame panels and other materials susceptible to moisture can lead to dampness and rot. It is essential to ensure proper ventilation, adequate drainage, and regular maintenance to prevent moisture-related problems.

Floor Defects

1. Uneven or Sagging Floors: The ground and first floors of Span Type K houses can become uneven or sag over time due to structural movement, inadequate support, or deterioration of the timber panels. Regular inspections and maintenance are essential to identify and address any issues with the floors.

2. Cracks in Concrete Floors: The concrete ground floors can develop cracks due to settlement, structural movement, or inadequate construction. These cracks can compromise the structural integrity of the property and should be addressed promptly.

Timber Frame Defects

1. Rot and Insect Infestation: The timber frame of Span Type K houses can be susceptible to rot and insect infestation, especially if exposed to moisture. Regular inspections and maintenance are essential to identify and address any issues with the timber frame.

2. Structural Movement: The coupled RS A-frames and other components of the timber frame can be affected by structural movement over time. This can lead to sagging roofs, uneven floors, and other structural issues. It is crucial to address any signs of structural movement promptly to prevent further damage.

Maintenance and Improvement Tips

Regular Inspections

Conducting regular inspections is essential to identify and address any potential issues with Span Type K houses. It is recommended to hire a qualified surveyor to conduct a thorough inspection and assessment of the property. Regular inspections can help identify any signs of structural damage, moisture ingress, or other defects early on, allowing for prompt repairs and maintenance.

Asbestos Management

If your Span Type K house contains asbestos-containing materials, it is crucial to manage them safely. Avoid disturbing asbestos-containing materials and seek professional assistance for removal or encapsulation if necessary. Regular inspections and maintenance can help ensure that asbestos-containing materials remain in good condition and do not pose a health risk.

Moisture Control

Moisture control is essential to prevent dampness, mould growth, and rot in Span Type K houses. Ensure proper ventilation, adequate drainage, and regular maintenance to prevent moisture-related problems. Address any signs of dampness, such as water stains, musty odours, or peeling paint, promptly to prevent further damage.

Structural Repairs

Address any signs of structural damage, such as cracks in the walls, sagging roofs, or uneven floors, promptly to prevent further damage. Hire a qualified contractor to conduct structural repairs and ensure that the property meets the required safety standards.

Energy Efficiency Improvements

Consider making energy efficiency improvements to your Span Type K house to reduce energy consumption and improve comfort. This can include upgrading insulation, installing energy-efficient windows and doors, and improving heating and cooling systems. Energy efficiency improvements can help reduce energy bills and increase the value of the property.

Conclusion

The Span Type K house, designed by Eric Lyons and manufactured by Span Developments Ltd, is a distinctive architectural style that offers a unique blend of aesthetic appeal and functional design. These properties, constructed between 1967 and 1969, are easily identifiable by their shallow pitch monopitch roofs, timber frame panels, and a combination of cladding materials.

While Span Type K houses are not classified as defective under the Defective Premises Act, it is essential to be aware of the potential hazards and risks associated with these properties. Conducting regular inspections, managing asbestos-containing materials safely, and addressing any signs of structural damage or moisture ingress promptly can help ensure the safety and longevity of the property.

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.

---