Sette secoli di manutenzione programmata per la conservazione dei paramenti lapidei della Cattedrale di Santa Maria del Fiore in Firenze

Reflecting upon the monuments maintenance, we should recall that this operation can be carried out with the substitution of the alterated portions. For some monuments there are circumstances that testifie the planning of substitutions since the beginning of the construction. As a matter of fact the historical documents owned by “Opera di Santa Maria del Fiore” which supervises the maintenance of the Cathedral, point out that in the original building technical tricks were taken that assumed following substitutions. These planned substitutions allowed to preserve the original structure until now in spite to what happened in other constructions where the maintenance caused also important rebuildings. Nevertheless in recent time substitutions have been performed that emphasize some incongruities in the selection of the stone materials. These problems could have been avoided with the help of the present knowledge on the composition and behaviour to alteration of the stone materials.