Q. When building a porch/stairs, do you have to completely tear the entire stairs and porch down first and start from scratch. Or can I just tear the steps down leave part of old porch and build on that. If I go this route would this cause problems later on down the line because I didn't tear the entire stairs/porch and start brand new. Please advise.
A. Concrete stairs are very heavy. They need a very strong sub-base to support the weight. I would recommend pouring them on a well compacted gravel base or a gravel base and concrete footing.
If that means tearing everything down and starting from scratch, then that's probably your best solution.