Question
When I try to edit my building slab I get the following message ‘Slab shape edit failed. The floor or roof is too thin.’ and cannot continue. How do I get around this?
Answer
This error will occur if the slab element structure is set to Variable thickness. This causes the bottom of the slab to remain flat and only the top of the slab will be modified with the shape edit tools. You can bring the node elevations up as much as you want, but when dropping them you are limited to the depth of the slab. Since setting the slab to variable means the floor base does not move, if you try to move a node below the thickness of the structure, there will be a point of zero thickness where it crosses. The error occurs when you try to push the top below the bottom.There are a few options to resolve the error: 1.Limit your negative offsets to the thickness of the variable layer. 2.Make the variable layer thick enough to accommodate your negative offset. 3.Clear the Variable check box in the floor type. Doing so will allow you to go as far as you want. However, the bottom of the roof will no longer be flat.