Why is it called four-six not material

Households living in the river area cover more civil dwellings of earth and wood structure, its style can be roughly divided into gray earth room, tile room and ridge ridge room three kinds of tiles. Gray earth room. Vertical wood for columns, columns support beams, beams and frame, purlins with rafters, whether or not the soil or mud billet wall, rafters on the white hemp or stack board, and finally mud or gray, the roof is more than one out of the water, the courtyard set up to the quadrangle of the majority. Because of folk taboo cover four or six rooms, said "four or six is not material", so most of the courtyard is three or five rooms, east and west room, south room of three questions, the street door depending on the location of the street. Tile house. Belonging to the medium housing, in addition to the first columns and frames and outside, brick wall base, soil base or adobe wall to the roof and then brick, wooden rafters and then tile roof, commonly known as the "shoes and hats tile room", the roof of the two out of the water, also known as the Daosi cap, the courtyard is still set up to the majority of the four courtyard, there are a small number of rich families in the courtyard set of left and right two across the yard, the door is located in the center of the entrance to the five blessings at the wall, the wall on both sides of the east and west of the two across the yard, and the door. There is a gate tower.

The ridge of the large tile house. In addition to the columns and frames brick base and outside, laying soft (with soil or mud billet) outside the hard (with brick) ponds, the rafters cover the top and then overlay tile, the roof in the middle of the "one" ridge, the east and west of the wall each up two ridges, called the "human" ridges, the ridges ridge angle emblems upward, as the wings of the bird, the ridges are carved with a spine beasts, called the "five ridges and six beasts" in order to be firm, on the tiles, drip tiles before and after the nails of a nail, commonly known as the "one tile and two nails". This is the folk of Uixian County on the most elaborate civil housing "a tile two nails, up the ridge tile room", its courtyard settings are also set up to quadrangle mostly, but most of them are two into two out or three into three out of the nine chain ring suite of courtyard, usually with pavilions, study, tent, living room, and so on.