Floor, in architecture, the area, or lower part of a room. which is in general covered with boards.

The best wood that can be selected for this purpose, is yellow deal, thoroughly seasoned ; which, if well laid, will for a long time retain its colour ; whereas the white sort, by frequent washing, becomes black; and presents a disagreeable appearance. The joints of the boards are usually made plain, so as barely to touch each other; but, as the materials are not always perfectly dry, the boards not unfre-quently shrink, and the water runs through them every time they are washed, by which the ceiling underneath is injured. To remedy this inconvenience, they should always be made either with edges, so as to fold over each other about half an inch, or with what is called dove-tails : in the latter case, the lower edge is nailed down, and the next driven into it, so that the nails are effectually concealed.

In the habitations of the labouring classes, the floors are generally made of loam. The best materials for this purpose are two-thirds of lime, one of coal-ashes, and a small portion of clay. The whole of these ingredients is to be well tempered with water, and left to Subside for a week or ten days, when it is to be worked up again. This operation should be repeated in the course of three or fourfdays, till the mixture become smooth and glutinous, when it will be fit for use. After the ground is made perfectly level, the composition is to be laid on to the depth of two and a half, or three inches, and carefully smoothed with a trowel. The hottest season of the year is the most proper for applying this mixture, which, when completely dried, will make a most durable floor, especially for malt-houses - See Country-Houses.