The San Ġwann tal-Għargħar chapel. Photo: Darrin Zammit Lupi

A 470-year-old building known as the San Ġwann tal-Għargħar chapel will be restored to its pristine state by the end of the year, according to the Restoration Directorate.

Works on the San Ġwann chapel, built in 1546, were set to start in June and would be completed within six months, the directorate’s director, Norbert Gatt, told this newspaper.

The chapel, situated on the road leading to Sliema, is thought to have been built by a family from the area known as Ta’ l-Għargħar. A sacristy was at a later stage built next to the chapel before this fell in a deteriorated state.

It was later restored and used by the Franciscan Capuchin fathers.

The exterior of the chapel, which is nowadays used by the Christian doctrine society MUSEUM for catechism lessons, has for many years required attention.

Mr Gatt said the directorate had already mapped and recorded the condition of the façade, the roof and the parvis using photo­grammetry, which involves the application of photographic and digital techniques to determine the state of the building.

“Works will include cleaning of the façade and other areas from biological growth, metal inserts and other materials. Stones will be cleaned using approved dry and wet brushing techniques with stiff nylon brushes and soft water. Biological growth will be removed using biocides,” he said.

Areas on the façade that are covered with plastering will be cleaned using more “delicate” techniques, Mr Gatt said. These would include micro scalpels – small, sharp-bladed tools that allow restorers to work on intricate details.

Before carrying out works on the deteriorated stone, harmful salt levels will be lowered through what is known as poulticing techniques, a process which involves the prolonged soaking of the stone to remove the excessive salts.

“Any new stonework will have to be carefully cut to size, inserted and grouted together with lime-based mortar. The roof and the parvis will be similarly cleaned and consolidated,” Mr Gatt said.

The restoration works were part of a scheme by the Ministry of Justice, Culture and Local Government, which is assisting local councils in the restoration of buildings and monuments.