Understanding the Doric House

The Doric house, a distinctive architectural style, emerged in the 1920s, designed and manufactured by the Modern Building Co. These properties are primarily found in suburban areas across the UK, often in semi-detached configurations. The Doric house is notable for its medium pitch hipped roof, rendered external walls, and unique structural features such as projecting first-floor walls and moulded cement string courses.

Historical Context and Manufacturing

Period Built and Typical Locations

The Doric house was predominantly constructed during the 1920s, a period marked by a significant demand for affordable housing in the UK. This era saw a surge in the development of suburban areas, where these houses were commonly built. The Modern Building Co., a prominent manufacturer of the time, played a crucial role in meeting this demand by producing a substantial number of these properties.

Manufacturers and Designers

The Modern Building Co. was responsible for the design and construction of the Doric house. This company was known for its innovative approach to building, utilising prefabricated components and modern construction techniques to expedite the building process. The design of the Doric house reflects the architectural trends of the 1920s, with an emphasis on functionality and simplicity.

Characteristics and Identification

Architectural Features

Doric houses are easily identifiable by their two-storey semi-detached structure, medium pitch hipped roofs covered with tiles or slates, and rendered external walls. The first-floor walls project over the ground floor walls, creating a distinctive profile. Other notable features include PC block piers at the corners, moulded cement string courses at the first-floor level, and exposed vertical cement cover strips.

Construction Details

Substructure

The substructure of a Doric house typically consists of concrete strip footings and concrete under-building. This robust foundation provides stability and durability, essential for the longevity of the property.

External Walls

The external walls are constructed using PC block corner and intermediate piers, with 10-inch walls to the first-floor level and 8-inch walls above. These walls are often rendered with roughcast building sheets, concrete, or asbestos cement sheets. Iron staples, timber wall plates, anchor irons, and moulded cement string courses are also integral components of the wall structure.

Roof

The roof of a Doric house is constructed with timber rafters covered with tiles or slates. This design provides adequate protection against the elements while maintaining the aesthetic appeal of the property.

Floors and Ceilings

The ground floor typically consists of timber boarding on timber joists, while the first floor follows a similar construction. Ceilings are often made of asbestos cement, a common material used during the period.

Typical Hazards and Risks

Structural Concerns

One of the primary concerns with Doric houses is the potential for structural issues, particularly related to the durability of reinforced concrete components. Over time, concrete can deteriorate due to factors such as carbonation and corrosion of steel reinforcements. This can compromise the structural integrity of the property, leading to costly repairs.

Asbestos

Asbestos cement sheets used in the construction of external walls and ceilings pose a significant health risk. Asbestos fibres, when disturbed, can become airborne and inhaled, leading to serious respiratory conditions, including asbestosis and mesothelioma. It is crucial to handle asbestos-containing materials with care and seek professional assistance for removal or encapsulation.

Damp and Moisture

Damp and moisture ingress can be common issues in older properties like the Doric house. Poor ventilation, inadequate damp-proofing, and deteriorating building materials can contribute to damp problems, which can lead to mould growth and structural damage.

Defective Premises Act and Doric Houses

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 Doric house is not specifically classified as defective under this Act, the potential for structural issues and the presence of asbestos necessitate thorough inspections and maintenance to ensure compliance with safety standards.

Inspection and Assessment Guide

Pre-Inspection Preparation

Before conducting an inspection of a Doric house, it is essential to gather relevant information about the property, including its construction details, previous maintenance records, and any known issues. This preparation will help identify potential problem areas and focus the inspection process.

External Inspection

Roof

Inspect the roof for any signs of damage, such as missing or broken tiles/slates, sagging, or water ingress. Check the condition of the timber rafters and ensure that they are free from rot and decay.

Walls

Examine the external walls for cracks, bulging, or other signs of structural movement. Pay particular attention to the condition of the roughcast render and any exposed cement cover strips. Check for signs of damp or moisture ingress, especially around the PC block piers and moulded cement string courses.

Internal Inspection

Floors and Ceilings

Inspect the ground and first floors for any signs of unevenness, sagging, or damage to the timber boarding and joists. Check the ceilings for cracks, staining, or other indications of water damage. Be cautious of asbestos-containing materials and avoid disturbing them.

Walls and Partitions

Examine the internal walls and partitions for cracks, damp patches, or other signs of structural issues. Check for any signs of movement or separation between the walls and the floor/ceiling.

Structural Components

Reinforced Concrete

Assess the condition of any exposed reinforced concrete components, such as the PC block piers and anchor irons. Look for signs of corrosion, spalling, or other deterioration. Consider using non-destructive testing methods, such as cover meters or ultrasonic testing, to evaluate the condition of the steel reinforcements.

Moisture and Damp

Use a moisture meter to check for dampness in the walls, floors, and ceilings. Pay particular attention to areas prone to moisture ingress, such as around windows, doors, and the base of external walls. Identify the source of any damp problems and recommend appropriate remedial measures.

Common Defects in Doric Houses

Structural Movement

Structural movement, such as subsidence or settlement, can be a common issue in Doric houses. This can manifest as cracks in the walls, uneven floors, or misaligned doors and windows. It is essential to identify the cause of the movement and implement appropriate remedial measures to stabilise the property.

Concrete Deterioration

The reinforced concrete components of Doric houses can deteriorate over time due to factors such as carbonation and corrosion of steel reinforcements. This can lead to spalling, cracking, and a loss of structural integrity. Regular inspections and maintenance are crucial to address these issues and prevent further damage.

Asbestos-Related Issues

Asbestos-containing materials, such as asbestos cement sheets used in the construction of external walls and ceilings, pose a significant health risk. It is essential to handle these materials with care and seek professional assistance for removal or encapsulation. Regular inspections should be conducted to ensure that asbestos-containing materials remain in good condition and do not pose a risk to occupants.

Damp and Moisture Ingress

Damp and moisture ingress can lead to a range of issues, including mould growth, timber decay, and structural damage. It is essential to identify the source of damp problems and implement appropriate remedial measures, such as improving ventilation, installing damp-proof courses, and repairing damaged building materials.

Maintenance and Repair Recommendations

Regular Inspections

Conduct regular inspections of the property to identify and address any issues promptly. This includes checking the condition of the roof, external walls, floors, ceilings, and structural components. Regular inspections can help prevent minor issues from escalating into major problems.

Addressing Structural Issues

If structural movement or concrete deterioration is identified, it is essential to implement appropriate remedial measures. This may include underpinning, crack stitching, or concrete repair techniques. Consult with a structural engineer to determine the most suitable approach for addressing structural issues.

Asbestos Management

If asbestos-containing materials are present, it is crucial to manage them safely. This may involve encapsulating the materials to prevent the release of asbestos fibres or arranging for professional removal. Regular inspections should be conducted to ensure that asbestos-containing materials remain in good condition.

Damp and Moisture Control

Implement measures to control damp and moisture ingress, such as improving ventilation, installing damp-proof courses, and repairing damaged building materials. Regularly check for signs of damp and address any issues promptly to prevent further damage.

Conclusion

The Doric house, with its distinctive architectural features and historical significance, remains a popular choice for home buyers and investors in the UK. However, it is essential to be aware of the potential hazards and risks associated with these properties, including structural issues, asbestos, and damp problems. By conducting thorough inspections and implementing appropriate maintenance and repair measures, you can ensure the longevity and safety of your Doric house 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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