Repair and reconstruction of civil structures - Assessment and Refurbishment of Steel Structures - page 149

Figure 5.14 The original roof structure
Figure 5.15 The new roof deck
The roof structure of the hall (Figure 5.14), with plan dimensions of 34.5× 39.2 m,
comprised three identical lattice direct-chord tie beams, roof trusses, and stiffeners
located between the tie beams. The tie beams and outer trusses were located onto the
external masonry. While corrosion losses on tabular surfaces reached 20 per cent, the
heaviest corrosion was in areas where steel rested on load-bearing walls. For this hall, the
following repairs were carried out:
• The roof deck was replaced by a new one (Figure 5.15), which was lighter included a
load-bearing roofing underlayer
• The lower chord of the outer trusses and the walls of trusses in areas where they rested
on the walls were reinforced.
• The inclined struts in the outer fields were supplemented by a new strut.