Historical Context and Manufacturing

The Tee Beam house, a distinctive type of system-built property, emerged in the post-World War II era, specifically between 1947 and 1955. This period was marked by a significant housing shortage in the UK, prompting the government and private sector to explore innovative construction methods to rapidly increase housing stock. Tee Beam Structures (Britain) Ltd, the primary manufacturer, played a pivotal role in this initiative.

These houses were predominantly constructed in urban and suburban areas, where the demand for quick and affordable housing was most acute. With only 260 units built, Tee Beam houses are relatively rare, making them a unique subject of interest for property buyers and investors today.

Design and Construction Characteristics

Architectural Features

Tee Beam houses are typically two-storey semi-detached properties. They can be identified by their medium pitch gable roofs covered with tiles or flat roofs covered with bituminous felt. The external walls are rendered with a roughcast or Tyrolean finish, using aerated Precast Reinforced Concrete (PRC) slabs throughout.

Structural Components

Substructure

The foundation of Tee Beam houses consists of concrete pad foundations below columns and concrete strip footings. This robust substructure provides a stable base for the entire building.

Frame

The main frame is constructed using Reinforced Concrete (RC) columns, bituminous felt permanent shuttering, RC ring beams, and metal fixings. This combination ensures the structural integrity and durability of the house.

External Walls

The external walls are made of rendered T-section aerated PRC panels with a discontinuous web, forming a 9-inch wall with a 5-inch cavity. This design not only provides insulation but also contributes to the overall strength of the building.

Internal Partitions

Internal partitions are typically made of 2-inch woodwool slabs or coir matting covered with cement. These materials were chosen for their cost-effectiveness and ease of installation.

Floors

The ground floor is constructed from concrete, while the first floor consists of a 2.5-inch RC slab on Precast Concrete (PC) T-beam units supported by RC ring beams. This design ensures a solid and stable flooring system.

Ceilings

Ceilings are generally made of plasterboard, providing a smooth and clean finish to the interior spaces.

Roof

The roof structure comprises timber trusses and concrete tiles, offering both durability and aesthetic appeal.

Typical Hazards and Risks

Structural Integrity

One of the primary concerns with Tee Beam houses is the potential for structural degradation over time. The use of PRC panels, while innovative at the time, has been found to be susceptible to issues such as carbonation and corrosion of the steel reinforcement. This can lead to a weakening of the structural integrity if not properly maintained.

Moisture Ingress

The bituminous felt used in flat roofs can deteriorate over time, leading to potential moisture ingress. This can cause damage to the internal structure and finishes, as well as create an environment conducive to mould growth.

Thermal Insulation

While the 5-inch cavity in the external walls provides some level of insulation, it may not meet modern standards. This can result in higher energy costs for heating and cooling the property.

Asbestos

Given the period during which these houses were built, there is a possibility that asbestos-containing materials were used in some components. Asbestos poses significant health risks if disturbed, so it is crucial to have a thorough survey conducted to identify and manage any asbestos presence.

Defective Premises Act and Designation

Tee Beam houses are designated as defective under the Defective Premises Act. This designation means that these properties have been identified as having inherent defects that could affect their structural integrity and safety. It is essential for potential buyers and investors to be aware of this designation and to take appropriate steps to assess and address any issues.

Inspection and Assessment Guide

Pre-Inspection Preparation

Before conducting an inspection, it is essential to gather all available information about the property, including any previous surveys, maintenance records, and repair history. This will provide a comprehensive understanding of the property’s condition and any potential issues.

External Inspection

Roof

• Check for signs of wear and tear on the tiles or bituminous felt.
• Look for any evidence of water ingress or damage to the roof structure.
• Inspect the condition of the timber trusses and concrete tiles.

Walls

• Examine the rendered finish for cracks, bulges, or other signs of deterioration.
• Check for any signs of moisture ingress, particularly around windows and doors.
• Assess the condition of the PRC panels and look for any signs of corrosion or carbonation.

Internal Inspection

Floors

• Inspect the concrete ground floor for any signs of cracking or movement.
• Check the first-floor RC slab for any signs of deflection or damage.

Partitions

• Examine the internal partitions for any signs of damage or deterioration.
• Check for any evidence of moisture ingress or mould growth.

Ceilings

• Inspect the plasterboard ceilings for any signs of cracking or sagging.
• Look for any evidence of water damage or staining.

Structural Components

• Assess the condition of the RC columns, ring beams, and metal fixings.
• Look for any signs of corrosion or deterioration in the steel reinforcement.

Asbestos Survey

• Conduct a thorough asbestos survey to identify any asbestos-containing materials.
• Ensure that any asbestos is managed in accordance with current regulations and guidelines.

Typical Defects and Maintenance

Common Defects

Carbonation and Corrosion

Carbonation of concrete and corrosion of steel reinforcement are common issues in Tee Beam houses. These defects can compromise the structural integrity of the property and require prompt attention.

Moisture Ingress

Flat roofs covered with bituminous felt are prone to moisture ingress, which can lead to internal damage and mould growth. Regular inspection and maintenance of the roof covering are essential to prevent these issues.

Cracking and Movement

Cracking in the rendered finish and movement in the concrete floors are common defects in Tee Beam houses. These issues can be caused by a variety of factors, including settlement, thermal movement, and structural degradation.

Maintenance Tips

Regular Inspections

Conduct regular inspections of the property to identify and address any issues promptly. This includes checking the roof, walls, floors, and structural components for signs of damage or deterioration.

Moisture Management

Ensure that the roof covering is in good condition and that any signs of moisture ingress are addressed promptly. This may involve repairing or replacing the bituminous felt or tiles.

Structural Repairs

Address any signs of carbonation or corrosion in the concrete and steel reinforcement. This may involve applying protective coatings, repairing damaged areas, or replacing affected components.

Asbestos Management

If asbestos-containing materials are identified, ensure that they are managed in accordance with current regulations. This may involve encapsulation, removal, or other appropriate measures.

Conclusion

Tee Beam houses, with their unique construction and historical significance, offer a fascinating opportunity for home buyers and investors. However, it is essential to be aware of the potential hazards and risks associated with these properties. By conducting thorough inspections and addressing any issues promptly, you can ensure the long-term safety and integrity 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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