Thin Spray-on Liner (TSL) is a new class of skin support which can be applied to the roof or sidewalls of an excavation for enhancing load-deformability behaviour. In this study, fibreglass-reinforced TSL (FR-TSL) was coated around the surface of samples made of rock-like materials and coal to compare the compressive and tensile behaviours with those of unlined samples. It was found that 5-mm FR-TSL could enhance the tensile strength of hydrostone by four times and change the failure mode from tensile to shear. A distinct “slight strain-softening zone” was observed in the stress–strain curves of cubical concrete and coal samples when coated with FR-TSL. The dissipated energy density and its rate were also higher in the post-yield regime, indicating effective confinement by the liner. The paper describes the experimental procedures and results in terms of deformability characteristics, elastic strain energy, and dissipated energy with and without the liner. The efficiency of liner performance is also quantified for its potential use in field applications.