My house is just about 100yrs old, it has solid wood posts for support under the main floor beam in the basement. Over time the house has settled and become quite unlevel. I have purchased the asjustable jacks to help raise the house up a little bit and to provide support under the side entrance and stairway. I know to asjust these only a little bit over time, my main question is it appears the previous owners poured a concrete floor in the basement, can I just set the jacks on the pooured concrete floor? Or do I need to poor some sort of footer to support the new posts? Thanks!