The nave is made of large split oak tree trunks, which was a traditional Saxon way of building. The nave is mostly original, and dendrochronological research in the 1960s dated it to 845. In 1995, however, this date was revised to 1053 +10–55 years (some time between 1063 and 1108). This range of dates is based on the dendrochronological date of the youngest timber (1053), plus a standard allowance of 10–55 years for sapwood rings which are assumed to have been weathered away.