SU 5425 is a deposit partially covering a lower, earlier, tufo pavement (5473) and thus appears to be equal to SU 5428. Additionally, the deposit abutts the rubble and ashlar wall 5400 in the north of room 9. This deposit may have accumulated naturally after the earliest phase, represented by lower tufo pavers 5473 and column base 5450 went out of use, or was deposited intentionally as a levelling surface (for an occupation, possibly associated with fragmented layers 5423 and 5414, layers no longer preserved).