The arcades themselves are splendid examples of the late 11th century transitional work when the Norman style was about to give way to Early English. The piers on the south side are all round with foliage and other moulding and with the square bosses having rounded mouldings. Those on the north side are again round except two which are formed by engaged shafts in the Early English manner which clearly indicates their transitional character. At this period the roof was much lower than at present, and traces remain of the 11th century clerestory the string courses for whose windows extend along the nave on either side beneath the present 15th century clerestory.
The fine west tower (picture) belongs to the 13th century and is connected to the earlier nave by a wide bay on either side. The western facade of this tower has a canopied doorway with triplet lancet arcaded windows above. A most unusual feature is the provision of very large buttresses which make the tower look wider than it actually is. The SW buttress contains a staircase leading to the upper stories and the NW buttress has a small chamber with a vaulted roof, above which is another chamber approached by a passage across the west window from the staircase in the SW buttress.
The top storey of the tower, together with the small recessed stone spire, belongs to the 14th century Decorated period when extensive alterations were carried out. To this period also belong the west doorway with flanking buttresses, and the buttresses to the aisles.
The most extensive alterations, however, took place in the 15th century. The earlier Norman clerestory was removed and the present one substituted with perpendicular windows, and, above, a very fine double hammer beam roof was built, similar to the one at Swaffham, Norfolk. This type of roof was an ingenious device of the heavy carpenter to bridge a wide span with a minimum of outward thrust, the weight being brought down on the wall posts resting on corbel brackets which are buttressed by the aisle roofs. But in a roof of this type it is the lower hammer beams which are taking most of the strain; the upper ones are more for ornamentation, and for this reason they are sometimes referred to as 'false'. The wall posts carry carved figures, every intervening one being a horizontal carved figure of an angel.