Historical Context and Manufacturing Details

The Howard Type B house, a notable example of post-war British architecture, was manufactured by John Howard & Co. Ltd. Designed by Phillip Powell and Eric Chick, these homes were constructed between 1945 and 1950. During this period, approximately 1,500 units were built, primarily to address the housing shortage following World War II. These properties are commonly found in various parts of the UK, particularly in areas that experienced significant wartime destruction.

Identification Characteristics

The Howard Type B house is easily identifiable by its distinct architectural features. These properties are typically two-storey semi-detached or terraced houses. One of the most striking features is the shallow pitch gable roof, which is covered with profiled asbestos cement sheets. The external walls are constructed with precast (PC) panels up to the ground floor window sill level, with flat asbestos cement sheets arranged in horizontal bands above. Timber cover strips are used to mask the corners, adding to the aesthetic appeal.

A unique characteristic of these houses is the recess at the separating wall on both the front and rear elevations. This recess is infilled with a projecting single-storey storage area on both elevations. The steel window frames further distinguish these properties from other post-war constructions.

Construction Details

Substructure

The substructure of the Howard Type B house consists of concrete pads below stanchions, PC block underbuilding, and oversite concrete. A damp-proof course (DPC) is also included to prevent moisture ingress.

Frame

The frame is a complex assembly of various steel components, including:

• 2 RSA (Rolled Steel Angle) and 2 RSC (Rolled Steel Channel) stanchions
• 2 RSA frames
• 4 RSJ (Rolled Steel Joist) single-storey stanchions
• 1 RSA spandrel support stanchion
• 2 RSJ floor support beams
• 9 RSJ ground and first-floor joists
• Braced RSA spandrel perimeter beams at first floor and eaves level
• RSA cladding rails
• 8 RSA roof trusses and 10 RSA purlins

These components are protected with red lead paint and black bituminous paint to prevent corrosion.

External Walls

The external walls are constructed with PC panels up to the ground floor window sill level. Above this, timber framing is clad with flat asbestos cement sheets arranged in horizontal bands. The cavity is filled with timber frame panels overlaid with aluminium-coated bituminous paper, infilled with woodwool slabs, and lined with plasterboard. Timber cover strips are used at the corners for additional protection and aesthetic appeal.

Separating Wall

The separating wall is a timber frame panel cavity wall infilled with woodwool slabs. It is backed with flat asbestos cement sheets up to the first floor and plasterboard above. Mineral wool insulation quilt is used in the cavity, and woodwool slabs are placed on both sides of the central roof truss.

Partitions

Internal partitions are made of timber stud infilled with woodwool slabs and lined with plasterboard.

Floors

The ground floor consists of tongue-and-groove (T&G) boarding on timber joists, while the first floor also uses T&G boarding on timber joists.

Ceilings

The ceilings are made of plasterboard on the ground floor and fibreboard on the first floor.

Roof

The roof is constructed with wire-reinforced polyethylene sarking and profiled asbestos cement sheets.

Typical Hazards and Risks

Asbestos

One of the most significant hazards associated with the Howard Type B house is the presence of asbestos. Asbestos cement sheets are used in the roof, external cladding, internal separating wall linings, and fire stops at the first-floor level. Asbestos poses serious health risks, including lung cancer and asbestosis, if disturbed. Therefore, any renovation or repair work must be carried out with extreme caution and by professionals trained in asbestos handling.

Corrosion

Superficial corrosion of RSA, RSC, and RSJ stanchions, particularly at the bases, is a common issue. Corrosion can also affect RSA cladding rails, RSA spandrel perimeter beams, and roof trusses. Regular inspections and maintenance are essential to prevent structural weakening.

Rain Penetration

Rain penetration at the joints of wall panels is another common issue. This can lead to dampness and mould growth, which can affect the structural integrity and indoor air quality. Proper sealing and regular maintenance can mitigate this risk.

Defective Premises Act

The Howard Type B house is not classed as defective under the Defective Premises Act. However, the presence of asbestos and potential for corrosion necessitate regular inspections and maintenance to ensure the property remains safe and habitable.

Inspection Checklist for Surveyors

When inspecting a Howard Type B house, surveyors should pay close attention to the following areas:

Asbestos

• Identify and assess the condition of asbestos cement sheets in the roof, external cladding, internal separating wall linings, and fire stops.
• Ensure that any asbestos-containing materials are undisturbed and in good condition.
• Recommend professional asbestos removal or encapsulation if necessary.

Corrosion

• Inspect RSA, RSC, and RSJ stanchions, particularly at the bases, for signs of corrosion.
• Check RSA cladding rails, RSA spandrel perimeter beams, and roof trusses for superficial corrosion.
• Recommend appropriate protective coatings or repairs to prevent further corrosion.

Rain Penetration

• Examine the joints of wall panels for signs of rain penetration.
• Check for dampness and mould growth inside the property.
• Recommend sealing and waterproofing measures to prevent rain ingress.

Structural Integrity

• Assess the condition of the concrete pads, PC block underbuilding, and oversite concrete in the substructure.
• Inspect the timber framing, woodwool slabs, and plasterboard linings for signs of damage or deterioration.
• Ensure that the roof structure, including wire-reinforced polyethylene sarking and asbestos cement sheets, is in good condition.

General Maintenance

• Check the condition of steel window frames and recommend repairs or replacements if necessary.
• Inspect the timber cover strips at corners and recommend maintenance or replacement if needed.
• Ensure that the damp-proof course (DPC) is intact and functioning correctly.

Typical Defects in Howard Type B Houses

Asbestos Degradation

Over time, asbestos cement sheets can degrade, releasing harmful fibres into the air. This is particularly concerning in areas exposed to weathering, such as the roof and external cladding. Regular inspections and professional asbestos management are crucial to mitigate this risk.

Corrosion of Steel Components

The steel components, including RSA, RSC, and RSJ stanchions, cladding rails, spandrel perimeter beams, and roof trusses, are prone to superficial corrosion. This can weaken the structural integrity of the property if not addressed promptly. Protective coatings and regular maintenance are essential to prevent further corrosion.

Rain Penetration and Dampness

Rain penetration at the joints of wall panels can lead to dampness and mould growth. This not only affects the structural integrity but also poses health risks to the occupants. Proper sealing and waterproofing measures are necessary to prevent rain ingress.

Timber Deterioration

The timber framing, woodwool slabs, and plasterboard linings can deteriorate over time, particularly if exposed to moisture. Regular inspections and maintenance are essential to ensure the structural integrity of these components.

Window Frame Corrosion

Steel window frames are prone to corrosion, particularly in areas exposed to weathering. Regular inspections and maintenance are necessary to prevent further deterioration and ensure the windows remain functional.

Conclusion

The Howard Type B house is a significant example of post-war British architecture, offering unique identification characteristics and construction details. While these properties are not classed as defective under the Defective Premises Act, the presence of asbestos and potential for corrosion necessitate regular inspections and maintenance. By understanding the typical hazards and risks associated with these properties, home buyers and investors can make informed decisions and ensure the long-term safety and habitability of their 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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