W. Va. Code § 36-4-7: Special covenant against encumbrances.

A covenant by a grantor in a deed, "that he has done no act to encumber the said lands," or a covenant of like import, shall have the same effect as if he had covenanted that he had not done or executed, or knowingly suffered to be done or executed, any act, deed or thing whereby the lands and premises conveyed or intended so to be, or any part thereof, are, or will be, charged, affected, or encumbered in title, estate or otherwise.