‹‹‹ Vitr. 7.1.4 | Table of Contents | Vitr. 7.1.6 ›››
5Pavements are, however, more fit to be used in the open air, inasmuch as timbers expanding in a moist atmosphere, and contracting in a dry one, or sagging in the middle, cause defects in the pavement by their settlements. Moreover, frosts and ice soon ruin them. But as they are sometimes required, they must be made as follows. Over the first flooring, boards, others crossing them, must be laid, fastened with nails; thus giving a double covering to the beams. The pavement is composed of two parts of fresh rubbish, one of potsherds, and two of lime.
5In the open air, specially adapted kinds of floors must be made, because their framework, swelling with dampness, or shrinking from dryness, or sagging and settling, injures the floors by these changes; besides, the frost and rime will not let them go unhurt. Hence, if necessity drives, we must proceed as follows in order to make them as free from defects as possible. After finishing the plank flooring, lay a second plank flooring over it at right angles, and nail it down so as to give double protection to the framework. Then, mix with new broken stone one third the quantity of pounded tile, and let lime be added to the mixture in the mortar trough in the proportion of two parts to five.