A ZINC roof is to be added to the tiny Becket Chapel at the grade 1 listed parish church of Lady St. Mary, Wareham.

Dorset Council has been told that the new roof is expected to save the 14th century structure from further water damage, while a longer term solution is explored.

The council has only given permission for the roof as a temporary measure - for no more than five years.

The church, which is of Anglo-Saxon origin has been extensively altered over the years, with the chapel, just 8 by 6 feet, thought to have been added at the same time as work on the chancel around 1325.

Dorchester specialist architects, Crickmay Stark, say the new roof will cover the existing stone corbel roof and is considered to be the best method of preserving the structure in the short term. It is expected to deal with most of the leaks directly via the roof.

A report from the architects says that the roof has been leaking for years with various attempts made to make it watertight, none of them fully successful.

“Repointing has been unsuccessful in the past, probably because the open joints are so deep that there is nothing to consolidate the mortar against. What mortar there is deep within the structure is saturated and has the consistency of paste,” said their report to the council.

“As anything short of re-building is unlikely to fully resolve the problem, and rebuilding would require loss of a number of historic stones, and has the potential risk of destabilising other parts of the building. Therefore, the existing weathered masonry is to be retained in-situ, but with open joints pointed in, and covered with sheet metal roofing to prevent water ingress. Lead was considered for this as a traditional material, but due to the risk of theft, zinc roofing is proposed. Another advantage of zinc roofing is that it is evidently a new intervention and not an historic part of the building.”

The small chapel, which many visitors to the church mistake for a buttress, has just one window, facing east.

A log book of church repairs, which was started in 1992, records work undertaken to the roof in 1996 and again in 2013 and 2017. In 2013 the log says: “Severe water penetration is occurring through this roof and the West wall is saturated: at the time of this inspection water was issuing from some of the joints.”