<p>Al–Si 4043 alloy was fabricated using wire arc additive manufacturing. Microstructure, microtexture and bulk texture characterization indicated grain coarsening along the build direction and a weak texture in the build. Porosity characterization using 3D micro-computed tomography revealed a variation in size, spatial distribution, morphology, and sphericity of the pores in the layer and interlayer regions of the build. A volume-averaged hydrogen diffusion model is applied for the prediction of hydrogen-based porosity. The model results indicate that the porosity fraction is affected by both the initial dissolved hydrogen and cooling rate during solidification. Furthermore, the model revealed that large-sized pores, the presence of which was confirmed from the experiments, begin to nucleate at low solid fractions (f_s ≥ 0.18). Mechanical properties variations in the build and fracture behaviour are discussed from the standpoint of microstructure and pore distribution. These findings can be useful for further optimisation of the deposition process to mitigate porosity.</p>