Based on standard fire test data extending over 50 years (Davey & Ashton 1953), Table 15 of BS5628-3 provides the fire resistance of walls for various forms of construction including:

• Section (A) - Loadbearing single-leaf walls (see Table 1)
• Section (B) - Non-loadbearing single-leaf walls (see Table 2)
• Section (C) - Loadbearing cavity walls (see Table 3)
• Section (D) - Non-loadbearing cavity walls (see Table 4)

Data is provided for walls made of different types of clay and concrete brick and/or block units, with or without surface finishes. The fire resistance periods considered range from 30 minutes up to 6 hours. Other forms of masonry construction are permitted provided evidence of satisfactory performance is produced based on results from standard fire resistance tests.

It is noteworthy that BS5628-3 does not specify a limit on the wall height. Although the test procedure in BS476 requires wall specimens to be at least 3m × 3 m, the heights of wall specimens in the standard fire tests seldom exceeded 3m. As a result, care must be exercised when designing walls with a height greater than 3m. This is because for walls greater than 3m in height, the lateral displacement due to thermal curvature at the wall’s mid-height will increase and they will collapse earlier, compared to the 3m high tested walls.