Parallel
Leviticus 14:42
Swete's Septuagint · Berean Standard Bible
καὶ λήμψονται λίθους ἀπεξυσμένους στερεοὺς καὶ ἀντιθήσουσιν ἀντὶ τῶν λίθων, καὶ χοῦν ἕτερον λήμψονται καὶ ἐξαλείψουσιν τὴν οἰκίαν.
So different stones must be obtained to replace the contaminated ones, as well as additional mortar to replaster the house.