CONSOLIDATION OF THE WOODEN BEAMS AND TRUSSES
The first phase of the work consisted in consolidating the surfaces of the wooden trusses over the lateral and central naves. Once the wooden structural elements had been catalogued, numbered and dismantled, they were treated to protect them from woodworm and dry rot and then primed with two coats of MAPEWOOD PRIMER 100 fluid epoxy impregnator. A layer of MAPEWOOD PASTE 140 epoxy adhesive pigmented in the colour specified by the Works Director was then applied. This phase was completed by bonding wooden slats to some of the areas treated with MAPEWOOD PASTE 140 thixotropic adhesive which, while still wet, had been broadcast with QUARTZ 0.5 quartz sand.
The second intervention involved consolidation of the wooden beams and trusses over the central nave by fastening two CARBOPLATE E170/50 plates near to the intrados of the chain with MAPEWOOD PRIMER 100, MAPEWOOD PASTE 140 and MAPEWOOD GEL 120. Metal inserts were added to the arches in the presbytery using 5 mm titanium threaded rods, which were fastened into the arches by drilling a series of holes and anchoring them with MAPEFIX EP 470 SEISMIC pure epoxy resin-based chemical anchor.
INTERVENTION ON THE DOME OVER THE PRESBYTERY
To strengthen the extrados of the dome, the Mapei FRP system was proposed, which involves the use of MAPEWRAP G UNI-AX 300/30 unidirectional, high strength, glass fibre fabric, applied with a line of epoxy resins such as MAPEWRAP PRIMER 1, MAPEWRAP 11, and MAPEWRAP 31.
This strengtheining system was applied on the properly prepared substrate with PLANITOP HDM RESTAURO. The system was linked to the perimeter walls with MAPEWRAP G FIOCCO glass fibre cord, anchored with MAPEFIX VE SF resin-based chemical anchor.
CONSOLIDATION OF THE VAULTED ROOFS
When consolidating the three limestone vaults unearthed during the archaeological digs MAPE-ANTIQUE ALLETTAMENTO was used for sealing the joints between the bricks. After the application of PRIMER 3296, a cap was made with PLANITOP HDM RESTAURO fibre-reinforced mortar and MAPEGRID G 220 glass fibre mesh.
For the new structural renders in the transepts and in the Sacramento and Annunziata chapels, it was recommended to use MAPE-ANTIQUE STRUTTURALE special mortar with MAPEGRID G 220 glass fibre mesh embedded in the mortar.
INTERVENTIONS ON THE INTERIOR
Wall plasters were restored by starting with a thorough meachanical cleaning. They were then consolidated with a series of micro-injections of a cement-free, lime-based hydrsaulic binder (MAPE-ANTIQUE I-15), filling the surface cracks, and then applying a coat of lime-based paint.
Dehumidifying renders were created using salt-resistant lime-based, cement-free products with MAPE-ANTIQUE RINZAFFO (applied in a 5 mm thick layer) and MAPE-ANTIQUE MC (in a 20 mm thick layer). MAPE-ANTIQUE LC, MAPE-ANTIQUE FC GROSSO and MAPE-ANTIQUE FC ULTRAFINE were also applied thereupon.
As for the interior floors, an aerated flooring system was also created to counteract rising damp from the substrate. This structure was made up of modular formworks and a screed made from TOPCEM PRONTO, a product which is ideal to build heated screeds thanks to its high thermal conductivity (λ = 2 W/mK). The slabs of marble were installed on the screed using GRANIRAPID adhesive in its white shade. The joints were then sealed with MAPESIL LM sealant.
The Carrara marble and Bardiglio grey inserts were installed using ELASTORAPID adhesive in its white shade.