# How to estimate the required thickness of a transfer floor

I am examining a high rise building project of 30 floors with a podium underneath and 2 basements. The structure in the tower and the podium varies between flat slabs, steel structure for wide spans, a huge shear wall around the tower's core, etc. The basement space has become inefficient as a parking area so I'd like to transfer this whole structure to an 8x8 or 16x16 grid of columns by using the transfer floor/slab. How can I estimate the required thickness of the transfer floor?

• @Menna Your edited question is more clear, but it would be really helpful to add a simple cartoon drawing. Oct 23, 2015 at 12:47
• @Menna - When you say the structure "varies from flat slabs, steel structure for wide spans etc." do you mean it varies between floors? Because all you need to care about for the numerical design of a transfer floor is the vertical loads coming down onto it. Hence slabs above, as horizontal surfaces, are irrelevant; as are the spans. What you need to worry about are columns and walls. Oct 23, 2015 at 15:43
• @Menna - And as hazzey has said, "it will be impossible to estimate any thicknesses". The thickness of a slab, i.e. its design, depends on the loads coming down onto it - the magnitude of the loads, their spacing etc. Suffice to say that even if you manage to put in sufficient detail in this question to allow this design, none of us are going to do it for you! We might do enough calculation on here to design a simply supported beam, but not for complicated loads of varying types over a large area. Oct 23, 2015 at 15:46