Closed stringer
An inclined beam with a flat top edge. Treads attach into side grooves; their ends are hidden from view.
01 /Specifics
Also an inclined beam like the sawtooth carriage, but with a perfectly straight top edge.
How treads attach
They are not placed on top — they slot into the side, into special grooves cut on the inner side of the stringer.
Side-view feature
From the side, the tread ends are not visible — they are completely hidden behind the beam's smooth surface. Closed-stringer stairs look more classic and massive.
