Double return stair treads have a mitered return on both the left and right ends.
Stair tread return length.
Because the mitered returns are both 1 wide the overall width of a double return stair tread will always be 2.
Stringers risers and treads.
Single return treads are measured by the overall length.
Stringers are the diagonally placed boards anchored at the top the header and the bottom the footer of the staircase.
The stringer is the backbone of the structure.
A 42 left return tread is 42 long overall and has a 40 3 4 throat 42 tread 1 1 4 return return this is a 1 1 4 solid stave that is bullnosed on one side and glued to fit along the open end of the stair tread.
There are three main components in a standard staircase.
Double return stair treads are always measured by the throat dimension the length between the two mitered returns.