How do I check deflection limits according to design codes?

Deflection limits are typically expressed as span/N where N depends on the type of structure and code. Common values: L/360 for floor beams under live load (AISC, NBR 8800), L/240 for roof beams, L/200 for members supporting plaster, H/400 to H/500 for column drift under service wind. Eurocode 3 uses similar values defined in the national annex. The code checks are performed under service (unfactored) loads, not ultimate (factored) loads. In CalcSteel, deflection is computed automatically from the FEM analysis and shown in the verification report alongside the limit — if deflection exceeds the limit, the member fails serviceability even if its strength is adequate.