To provide a blocking-up material capable of easily performing execution work, capable of effectively using resources and capable of reducing a building waste material by installing a wide sheet on the main body upper surface composed of a corrosion resistant construction material endurable to weight of an outer wall material.

A blocking-up material 1 is composed of a main body 12 and a sheet 13 stuck to the upper surface. The main body 12 is made of hard urethane, and is formed in an almost rectangular cross-sectional shape. The sticking sheet 13 is formed of a vinyl pressure sensitive adhesive tape, and a mold separable sheet is stuck to the reverse of the part projecting to one side of the main body 12. A space part between the reverse of a panel 1 and respective ruler angles 4 is blocked up by the main body 12, the sheet 13 is put in an upward bending state, and the mold separable sheet is separated to be stuck to the reverse of the panel 1. Afterwards, mortar 9 is filled between the reverse of respective panels 1 and a floor 7. The blocking-up material 11 is used as a spacer when horizontally laying the panels at transport time and storage time to thereby reduce a cost and manhours of execution work as well as to reduce a building waste material by obviating a wooden spacer.