Connecting to a Concrete Floor - Straight-Cut Connection
Using the straight cut connection can present the same problems as with connecting to a steel floor. The Foot-Fall may be limited and, depending on the thickness of the concrete, the last stair tread may impede the concrete. Then there’s also the problem of the concrete itself which may not be of sufficient quality and dimensional accuracy to allow this connection. Generally, this is not considered good practice.
To make this connection, the concrete floor must be in place
Another option is to fasten a seating-angle across the top of the stringers, allowing the stair to ‘seat’ onto the supporting beam. This connection must be made before the concrete floor is cast.
When fixing the seating angle, it’s always advisable to provide packers between the seat and the top of the beam for levelling.
Such connections should only be considered when there are limits on the horizontal space providing no other option. They are both unsightly and impractical, but their low-cost makes them fairly common.
This connection must be made prior to pouring the concrete floor.
The mitered connection will be more expensive to fabricate, and will take-up more horizontal space, but they are safer, neater, and effectively eliminate all the problems associated with the square-cut.
Connecting to a Concrete Floor - Miter-Cut Connection
A mitered connection will connect to the supporting beam only and will work whether the concrete floor is in place or not. It will allow the option of creating a small safety landing to improve the ‘sight-line’ or may use the leading-edge of the concrete floor to double-up as the beginning of the sight-line.