DECO 20 Clear Penetrating Concrete Sealer (DECO 20) is an alternative material replacing bituminous products. It is approved for dampproofing of masonry block, pre-cast and poured concrete foundation walls. DECO 20 is a special formulated clear penetrating sealer designed for the environmental requirements in the dampproofing industry. DECO 20 produces a highly effective breathable moisture barrier, by reducing water vapor transmission.