When considering a property purchase in the UK, understanding the intricacies of different property types is crucial. One such property type that often piques the interest of home buyers and investors is the Mark house. This article delves into the essential aspects of the Mark house, providing a detailed overview of its construction, typical characteristics, potential hazards, and inspection tips. As an expert surveyor with extensive knowledge of system-built properties, I aim to offer valuable insights to help you make informed decisions.

Historical Context and Manufacturers

The Mark house, also known as the Marnel, was manufactured between 1965 and 1975. This period saw a surge in the construction of system-built properties, driven by the need for rapid housing solutions. The primary manufacturers of the Mark house were Marnel Holdings Ltd, Marnel Development Co. Ltd, and the Five Oaks Group. The design of these houses was spearheaded by notable designers A. Clark and the firm Marsh and Jolley.

During this decade, approximately 50 Mark houses were built, predominantly in suburban areas. These properties were designed to cater to the growing demand for affordable and efficient housing solutions. The Mark house’s construction methods and materials reflect the architectural and engineering trends of the time, making them a unique addition to the UK’s housing landscape.

Identification Characteristics

Identifying a Mark house is relatively straightforward due to its distinct architectural features. These properties are typically two-storey detached, semi-detached, or terraced houses. Key identification characteristics include:

• Medium Pitch Gable Roof: The roof is covered with interlocking concrete tiles, providing a durable and weather-resistant surface.
• Rendered Front and Rear Walls: The walls are rendered up to the first-floor level, with tile hanging above. Alternatively, some variations feature horizontal timber boarding between the ground floor window head level and the first-floor window sill level.
• Rendered Gable Wall: The gable wall is rendered, with the apex clad in a band of shiplap boarding and tile hanging above.
• Flat Canopy Over Front Door: A flat canopy supported by tubular steel props is a common feature above the front door.
• Deep Fascia at Eaves Level: The deep fascia at the eaves level adds to the distinctive look of the Mark house.

These characteristics make the Mark house easily recognizable and distinguishable from other property types.

Construction Details

Understanding the construction details of the Mark house is essential for assessing its structural integrity and potential risks. The construction of these houses involves several key components:

Substructure

The substructure of the Mark house includes concrete pads below stanchions and a concrete foundation along the gable wall. A concrete slab forms the base, with a damp-proof course (DPC) to prevent moisture ingress.

Frame

The frame consists of six rolled steel joist (RSJ) stanchions, four rolled steel channel (RSC) perimeter beams, and one RSJ floor support beam. The frame layout is designed to provide structural stability and support the weight of the building.

Protective Coating

The protective coating used on the steel frame is not well-documented. However, it is essential to inspect the frame for signs of corrosion or deterioration, as this can impact the overall structural integrity.

External Walls

The external walls are constructed using storey-height timber frame panels faced with bituminous paper. The front and rear walls are clad with rendered woodwool slabs and lined with foil-backed honeycomb plasterboard up to the first-floor level. Above this level, the walls are clad with tile hanging on timber battens and lined with chipboard backed with polystyrene insulation.

The gable wall is made of rendered brick, with the apex clad in shiplap boarding and tile hanging above. The interior lining consists of foil-backed honeycomb plasterboard up to the first-floor level and chipboard backed with polystyrene insulation above.

Separating Wall

The separating wall between properties is constructed using concrete blocks lined with foil-backed honeycomb plasterboard. This provides a degree of sound insulation and fire resistance.

Partitions

Internal partitions are made of timber stud walls lined with honeycomb plasterboard. These partitions are relatively lightweight and easy to modify if necessary.

Floors

The ground floor is a concrete slab, providing a solid and stable base. The first floor consists of chipboard on timber joists, offering a lightweight and flexible flooring solution.

Ceilings

Ceilings are constructed using plasterboard, which is a common material for residential properties due to its ease of installation and finishing.

Roof

The roof structure comprises timber trusses, bituminous felt, timber battens, and interlocking concrete tiles. This combination provides a robust and weather-resistant roof.

Typical Hazards and Risks

While the Mark house offers several advantages, it is essential to be aware of potential hazards and risks associated with this property type. Some common issues include:

Corrosion of Steel Frame

The steel frame is susceptible to corrosion, particularly if the protective coating is inadequate or damaged. Corrosion can compromise the structural integrity of the building, leading to potential safety hazards.

Moisture Ingress

Moisture ingress can occur due to inadequate damp-proofing or damage to the external cladding. This can lead to issues such as mould growth, timber decay, and deterioration of internal finishes.

Insulation and Thermal Performance

The insulation used in Mark houses may not meet modern standards, leading to poor thermal performance and higher energy costs. Upgrading the insulation can improve energy efficiency and comfort.

Asbestos

Asbestos-containing materials were commonly used in construction during the 1960s and 1970s. It is essential to check for the presence of asbestos in the property and take appropriate measures for its safe removal or encapsulation.

Structural Movement

Structural movement can occur due to ground conditions, foundation issues, or deterioration of the building materials. Signs of structural movement include cracks in walls, uneven floors, and misaligned doors and windows.

Defective Premises Act

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 Mark house is not specifically listed as defective under this Act, it is essential to address any identified defects to ensure compliance with legal requirements and maintain the property’s value and safety.

Inspection Tips for Surveyors

When inspecting a Mark house, surveyors should follow a systematic approach to identify potential issues and assess the property’s condition. Key areas to focus on include:

External Inspection

• Roof: Check for missing or damaged tiles, signs of sagging, and the condition of the timber trusses.
• Walls: Inspect the rendering for cracks, bulging, or signs of moisture ingress. Check the condition of the tile hanging and timber boarding.
• Gable Wall: Examine the rendered brickwork and the shiplap boarding for signs of deterioration.
• Canopy: Ensure the flat canopy over the front door is securely attached and free from corrosion or damage.

Internal Inspection

• Frame: Look for signs of corrosion or damage to the steel frame. Pay particular attention to areas where the protective coating may be compromised.
• Walls: Check for cracks, damp patches, and signs of structural movement. Inspect the insulation and internal linings for any signs of deterioration.
• Floors: Assess the condition of the concrete ground floor and the chipboard first floor. Look for signs of unevenness or movement.
• Ceilings: Inspect the plasterboard ceilings for cracks, sagging, or water stains.
• Partitions: Check the condition of the timber stud partitions and the honeycomb plasterboard linings.

Services

• Electrical: Ensure the electrical system is up to date and compliant with current regulations. Look for signs of outdated wiring or inadequate earthing.
• Plumbing: Check for leaks, corrosion, and the condition of the pipework. Ensure the plumbing system is functioning correctly.
• Heating: Assess the condition of the heating system, including the boiler, radiators, and pipework. Ensure the system is efficient and well-maintained.

Typical Defects and Maintenance

Understanding the typical defects associated with Mark houses can help in planning maintenance and repairs. Common issues include:

Corrosion of Steel Frame

Regular inspections and maintenance of the steel frame are essential to prevent corrosion. If corrosion is detected, it may be necessary to treat the affected areas and apply a protective coating.

Moisture Ingress

Addressing moisture ingress involves identifying and repairing the source of the problem. This may include repairing damaged rendering, improving damp-proofing, and ensuring proper drainage around the property.

Insulation Upgrades

Upgrading the insulation can significantly improve the thermal performance of the property. This may involve adding additional insulation to the walls, roof, and floors.

Asbestos Management

If asbestos-containing materials are present, it is essential to manage them safely. This may involve encapsulation or removal by a licensed asbestos contractor.

Structural Repairs

Addressing structural movement may require underpinning the foundations, repairing cracks, and reinforcing the building structure. It is essential to consult a structural engineer for a thorough assessment and appropriate remedial measures.

Conclusion

The Mark house, with its unique construction and historical significance, offers both opportunities and challenges for home buyers and investors. Understanding the typical characteristics, potential hazards, and maintenance requirements of these properties is essential for making informed decisions. By following a systematic approach to inspection and addressing any identified issues, you can ensure the long-term safety and value 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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