Slabs are considered one of the most exposed elements to disasters and deformities that can be clear to the viewer. These deformities are reflected as sign of defects that appear clearly on big slabs. So, here comes the importance of applying and designing accurate slabs. The purpose of this research is stating the need for persistent efforts to get a better form of the slabs in order to increase their ability to be able to carry any outside extra weights without the appearance of any deformities that might take place during the period of investing the building. When deformities happen, they have bad effect on the beauty and main function (purpose) of the building. This research includes an experimental study for the real applicable slabs under our supervision, in addition to a theoretical study about the deflection appearing on the slabs by taking into consideration the plastic specifications of the concrete and the formation of cracks. This research aims at constructing reflexive deflections in the slabs during the construction period and measuring the actual deformities and watching them through a period of time, then comparing them with the theoretical expected deformities. The findings that we could get at the end of our research are supposed to play a main role in choosing the best design for the mandate slabs and at the same time getting the best value for the reflexive deflection that can be used in the slab to make it better functionally and to increase its ability to resist the outside applied weights. We hope this is just a start for more research in this field.