whats the purpose of wedges on stairs?

[Rick Reinsma]

I have to build a standard stair case and wondered what the purpose of the wedges . Can't you just build the stairs with dado and groove cuts and assemble them that way with out wedges ? Thanks for your help....Rick

[Richard Wolf]

Sure you could build a staircase without wedges. The older style contemporary stairs, with no risers just 2" thick treads are built that way. The advantage of tapered dados with wedges is to insure a very tight joint between the stringers and the treads and/or risers. There is a lot of stress on a staircase and a very tight joint helps hold things together and reduce squeaks.

Richard