Margam’s polygonal chapter house, one of the earliest in Britain, had long been sadly neglected. The lead had been stripped from its roof to cover the banqueting house of the Mansels and merely replaced by oiled paper, which provided little protection from the elements. The roof and central column collapsed in 1799 after severe frosts.
At the turn of the century a further petition from the Margam parishioners advised Talbot of their concern at the serious state of decay of the church and of the south aisle in particular. Talbot eventually acceded to their wishes and restoration began in the spring of 1805, largely due to the influence of Dr John Hunt, the Margam incumbent. Work commenced on condition that the parishioners agreed to meet the cost of restoring the eastern section of the north aisle to its original width. At Talbot’s expense a family vault was constructed there. Charles Wallis, a Swansea architect, began the restoration of the church but escalating costs and general dissatisfaction prompted a search for an alternative design, that of a Mr Heverfield being accepted.
During the second half of the 18th century, as a result of general decay and apathy, the church was in a lamentable condition and fast becoming ruinous. By late 1760’s the Margam parishioners, alarmed at the state of the crumbling edifice, petitioned Thomas Mansel Talbot to effect repairs, but their pleas fell on deaf ears. A suggestion that funding might become available if the parishioners agreed to the dismantling of the south aisle, thereby enlarging the gardens was thankfully rejected. By 1787, the church was described as being like too many other country churches – “in a very slovenly state, unpaved and without railings”.