The electrical resistance of a Nicalon-reinforced lithium aluminosilicate grass-ceramic with Ta2O5 additions was used as an indicator of fibre and TaC/Carbon coating fracture during flexural testing. The resistivities of fibres in the composite were significantly lower than the free fibres owing to the high conductivity carbon and TaC coatings which formed during hot pressing. Hot-pressing times beyond 0.5 h resulted in a degradation of flexural strength via the formation of a strongly bonded TaC layer at the expense of the carbon debond layer.