This paper investigates the relationship between the flexural stiffness category of textile carbon reinforcement, concrete type, and spacer configuration for casting thin plates. Large distances between adjacent spacer lines can result in unacceptable tolerances, according to the recently published German guideline components with non-metallic reinforcement. The tolerances have been studied in the vertical position of two different textile carbon reinforcement casted in 1 m² plates with a height of 4 cm. The study states that higher flexural stiffness of carbon reinforcement and an increased number of spacers per square meter can reduce positional deviations.