Stone

Animated illustration of the stone construction. Here the structural support system of the stone masonry is diagramed and can be rotated to see the elements working together. Stone vaults, which will be the last phase of construction, weigh heavily on the outer walls of the clerestory. The timber roof and lead sheathing add to the weight Without adequate buttressing, the upper walls would lean out, buckle and collapse. The buttressing system consists of heavy vertical masses of masonry built against the side aisle walls and rising above them, and quadrant arches which abut the clerestory wall at a point where the outward thrust of the vaults is greatest.