We analyze in detail the evolution of curvature of 3C-SiC layers grown on vicinal silicon substrates. A common feature of (100) and (111) oriented layers is a strongly asymmetric wafer bending that may suggest an anisotropic stress relaxation within the layer. A comparative study of the curvature, lattice parameter, surface morphology and structural defects for the off-angles ranging from 0.5° to 6° is performed in order to confirm or disprove this hypothesis. We find a homogeneous, tensile in-plane lattice deformation. We also show the correlation of the orientation of the high and low curvature axes with the morphology and defect pattern of the layer.