original C14th timber roof with cusped wind-bracing and in the chancel a later transition to 'wagon' roof by addition of diagonals to each rafter set (there would have been a ceiling following the arched line, but removed recently.
Interestingly this roof has survived with just the one inserted tie-beam, whereas the Colwall (lower image) one has had to be messed around considerably. The 2 differences are that Colwall has aisles but no vertical 'ashlar posts' on the inside.
This roof form was undoubtedly spawned by the Guesten Hall roof at Worcester Cathedral, built in 1320