When I build a skyscraper out of LEGO and the floor above is weak do I remove the flooring from above and a pillar underneath and then put the floor back or something?
Extra support in form of pillars/walls underneath (remember that also weighs something and as such should be supported) is one (and probably the most widely used) solution, another would be to build the floor thicker, and depending on how weak the floor is and how much it has to support yet another solution might be to just not care.
Most real-world buildings will have one or both of the following features:
- Load bearing columns - in tall tower blocks you'll often find the lifts, emergency stairs, etc form a central column that the floors can be anchored to.
- Supporting beams - these are typically steel beams that travel from one load bearing wall to another, and the floor will then rest on those.
Where you have both these features, the supporting beams will go from the exterior walls to the support columns, or from column to column, providing both rigidity to the structure and support for the floors.
Your LEGO builds should aim to incorporate those features if you need to support plates that are smaller than your building's floor plan.