Clapboard Siding (1,0 x 1,5)

One spacing, two different buildings

White polystyrene one millimeter thick, an area measuring 150 by 300 millimeters, crossed along its whole length by horizontal grooves 1.5 mm apart.

The most common mistake when building structures is the assumption that a textured sheet has a fixed reduction of its own. It does not. It carries only an absolute dimension, and it is the model around it that decides what that dimension means. At a reduction of one to forty-eight, a spacing of 1.5 mm reads as a board seventy-two millimeters wide, that is, a narrow but entirely ordinary siding board. The same sheet at a reduction of one to twenty-four gives thirty-six millimeters, which is no longer a board at all: at that size it will rather be a shutter slat, the infill of a shutter or the soffit above a gutter.

The decision therefore falls somewhere other than on the sheet itself. Set a door beside it. Its clear height tends to be around nineteen hundred millimeters, which is forty millimeters at a reduction of one to forty-eight and eighty at a reduction of one to twenty-four. If the doorway matches, so does the siding; if they disagree, no amount of fine engraving will help.

The sheet is homogeneous all the way through, so no different core color is left after a cut. It is cut by scoring and snapping and glued with solvent cement, which welds the joint, or with super glue if you are in a hurry.

Cut the openings for windows and doors before you glue the wall to the others. A hole is drilled inside the future opening, a file blade is led inside and the cut is taken to the corners. The most common damage happens when finishing the edges: the fine board at the edge of the opening breaks off easily, so remove the last tenth with a file, not with a knife. The window frame then borders the cut and hides any unevenness.