The listed train shed roof which is 105 metres (344 ft) wide between platforms 1 and 12, comprises four spans; two of the spans, 185 metres (607 ft) in length, were built over the eastern part of the station during the 1860s while the other two, at the western side measuring 150 metres (490 ft), were constructed in the early 1880s.
The roof is supported by masonry walls at the outer edges, which have round-headed windows alongside platforms 1 and 12, and rows of cast iron columns along the platforms in its interior space.
The roof spans have an arrangement of wrought iron trusses with supporting cast iron struts on girders, which are evenly spaced between the columns.

As built, the roof was largely covered with slates with some areas of glazing; over time, the slates were  replaced with boarded felt.
Between 1997 and 1999, the station roof was refurbished and the traditional cladding was replaced with around 10,000 panes of toughened glass that 'float' above the wrought iron trusses.
Layers of nets have been installed, to catch falling glass in the event of any of the panes were to break.

Below the train shed is the undercroft that was used as a goods station.
Cast iron columns and brick arches support the terminal platforms directly above.
Since the early 1990s, the undercroft accommodates the Metrolink station, its tracks, sidings, and car parking.
Before it was reused for the Metrolink, the cast-iron columns throughout the undercroft were encased in concrete as a protective measure against collision.

George W. Buck designed the original skew arch bridge over Fairfield Street; it had ten cast iron arch ribs, which formed one part of the brick arch viaduct, and was topped with open stonework parapets.
The bridge was subsequently widened and wrought iron plate girders and transverse girders were added to support longitudinal joists with iron arch plates.
In the 1960s, in the reconstruction programme, the cast iron arches and spandrels were  encased in concrete.
Platforms 13 and 14 are situated on top of this bridge.

Many of the original station buildings were demolished during the 1960s to clear the way for a new approach.
The main entrance leads to a concourse with ground floor, and since the 2000s, mezzanine levels.
The Fairfield Street entrance leads to the Metrolink station in the undercroft and is linked to the rail platforms by escalators.
Between 1997 and 2002, a redevelopment programme revised the station's layout and a glass partition wall with ticket barriers separating the concourse from the platforms was constructed.
The station's approach leading to the end of Piccadilly was constructed in 1969 along with the "wavy" fronted Gateway House designed by the architect Richard Seifert.
 Gateway House was modernised during 2003.
The listed train shed roof which is 105 metres (344 ft) wide between platforms 1 and 12, comprises four spans; two of the spans, 185 metres (607 ft) in length, were built over the eastern part of the station during the 1860s while the other two, at the western side measuring 150 metres (490 ft), were constructed in the early 1880s. The roof is supported by masonry walls at the outer edges, which have round-headed windows alongside platforms 1 and 12, and rows of cast iron columns along the platforms in its interior space. The roof spans have an arrangement of wrought iron trusses with supporting cast iron struts on girders, which are evenly spaced between the columns.
As built, the roof was largely covered with slates with some areas of glazing; over time, the slates were  replaced with boarded felt. Between 1997 and 1999, the station roof was refurbished and the traditional cladding was replaced with around 10,000 panes of toughened glass that 'float' above the wrought iron trusses. Layers of nets have been installed, to catch falling glass in the event of any of the panes were to break.
Below the train shed is the undercroft that was used as a goods station. Cast iron columns and brick arches support the terminal platforms directly above. Since the early 1990s, the undercroft accommodates the Metrolink station, its tracks, sidings, and car parking. Before it was reused for the Metrolink, the cast-iron columns throughout the undercroft were encased in concrete as a protective measure against collision.
George W. Buck designed the original skew arch bridge over Fairfield Street; it had ten cast iron arch ribs, which formed one part of the brick arch viaduct, and was topped with open stonework parapets. The bridge was subsequently widened and wrought iron plate girders and transverse girders were added to support longitudinal joists with iron arch plates. In the 1960s, in the reconstruction programme, the cast iron arches and spandrels were  encased in concrete. Platforms 13 and 14 are situated on top of this bridge.
Many of the original station buildings were demolished during the 1960s to clear the way for a new approach. The main entrance leads to a concourse with ground floor, and since the 2000s, mezzanine levels. The Fairfield Street entrance leads to the Metrolink station in the undercroft and is linked to the rail platforms by escalators. Between 1997 and 2002, a redevelopment programme revised the station's layout and a glass partition wall with ticket barriers separating the concourse from the platforms was constructed. The station's approach leading to the end of Piccadilly was constructed in 1969 along with the "wavy" fronted Gateway House designed by the architect Richard Seifert.  Gateway House was modernised during 2003.
Manchester Piccadilly station