foundation plate thickness

The foundation plate thickness for any built object is the median vertical distance between the upper surface and the lower surface of a mat foundation or of the foundation plate in any composite foundation using a mat.

The distance is taken vertically through the foundation plate. It concerns the thickness of the plate itself, not the depth of excavation or the height of walls rising from it.

Where the plate varies in thickness, the median describes its thickness across the defined built object. One locally thickened or thinned section does not by itself establish that median.