Section of roof at Ulster Carpet Mills

The Department's description

Exterior description and setting

Small section of Belfast Truss roofing belonging to a building of perhaps c.1920s, now almost completely submerged to all sides within the middle of a very large carpet factory building. The factory is set to the N side of Garvaghy Road, to the NW of the centre of Portadown.

The section of roofing belongs to a building which was probably originally either free-standing or partly exposed to ground level, but which can only now be seen as a portion of roofing set in a vast factory complex. The factory itself appears to have grown to its present size over many years and consequently displays various different types of building styles and roof construction. The section itself measures roughly 10.5m x 7.5 and is covered in corrugated metal with what appears to be a circular vent projecting through it close to the eastern end. Below the roof, to the N side, there is a small section of exposed façade which is in brick with large areas of glazing. The small section of the exposed W gable appears to be rendered. The exposed portions of the E gable and S ‘elevation’ could not be seen, however internal evidence shows that there is a row of windows to the S similar to those to N.

Historical information

The building to which this section of roofing belongs may date from the 1920s, and appears to have been at least partly originally exposed to ground level.

The Belfast truss was developed in the mid-nineteenth century to meet the demand for efficient, lightweight and long span roofs brought about by the industrial revolution. A detailed description of the historical development of the Belfast truss is included in the record for HB18/08/139. In brief, the first known reference to a curved wooden felted roof structure supported by bowstring girders is in an advertisement in the Dublin Builder for 1866 by the Belfast firm of felt-makers, McTear & Co. McTear’s continued making trusses until they went out of business in 1908.

A second Belfast felt supplier, Anderson & Co., began to produce trusses, to a slightly different design, in 1886. In 1896, Anderson’s launched their Mk II version; promoted as maximising long spans whilst maintaining light weight. This model was subsequently used by other companies, and is referred to by historians as the Belfast truss, although this term is widely used to apply to all timber bowstring trusses where the internal bracing members meet not on the bottom of the truss as was the convention but on the top curved member.

Criteria for listing: architectural interest

Not listed

Criteria for listing: historic interest

Not listed

Evaluation

Small section of Belfast Truss roofing belonging to a building of perhaps c.1920s now almost completely submerged to all sides within the middle of a very large carpet factory complex. A good intact example of a Belfast Truss roof whose impact has been negated by the virtual ‘disappearance’ of the building to which it belongs.

General comments

Surveyed as part of the Belfast Roof Truss survey.