The prefabricated pile footing structures presented in this paper demonstrate that large (3’ × 2’ × 1’), mostly hollow structures are indeed manufacturable through industrial large scale polymer additive manufacturing (ILSPAM). Additionally, this work identifies manufacturing process defects which resulted from the production of such structures. Processing failures during manufacturing prompted the modification of process control parameters (layer height, material choice). This yielded four specimens, each with a unique treatment modification combination. This paper utilizes an experimental setup [1] for analyzing the effect of various processing treatments on large-scale additively manufactured thermoplastic structures. Specifically, it presents and compares the uniaxial compression results of layer height and material treatments on pile footings made with virgin and recycled glass fiber reinforced PETg (PETg-GF) using cyclic loading experiments. Force-displacement experiments were conducted to determine and compare the effects of such modifications on the uniaxial compression performance of the different specimens. The authors note that the data supports the hypothesis that increasing layer height will decrease the stiffness of additively manufactured structures. Furthermore, the cyclic uniaxial compression experiments conducted on the pile footings validate the applicability of the related experimental setup for multiple large-scale additively manufactured structural products. Finally, the authors recommend further experiments and analysis to determine the effect of material choice, as well as experiments with smaller specimens to address the limitations of measuring large-scale structures.