Abstract: A vented filtration device comprising a closed, flexible and compressible housing having a liquid inlet and a liquid outlet. The housing includes an internal passage connecting the inlet and the outlet. A liquid filter assembly is disposed within the passage between the inlet and outlet thereby defining an upstream pressure section between the inlet and the filter and a downstream pressure section between the filter and the outlet. This assembly includes a flexible, porous bacteria retentive filter membrane, a flexible, porous support material overlying one surface of the filter membrane and a frame having at least one large central opening overlying the opposite surface of the filter membrane. A gas vent located in the housing communicating with the upstream pressure section of the passage is adapted to allow gas but not liquid to pass from the upstream section out of the housing.

Abstract: A cementitious facing material for bonding to either preformed masonry building units or to existing masonry and concrete walls, floors or slabs; comprising a suitable proportioned dry mixture of (1) white Portland cement, (2) washed and screened sand of glass making quality, and (3) paint pigments. These thoroughly mixed dry materials are activated into a moist colored concrete mixture of troweling consistancy by the addition of a wetting agent in the correct proportions of water and polyvinyl acetate resin emulsion (containing approximately 50% of solids). The proportions of water and resin in the wetting agent to be based upon the desired percentage of resin to be retained in the facing material after it has been cured. A coating of bonding material is applied to the face of the preformed masonry unit or to the existing masonry or concrete wall, floor or slab and the facing is applied over the bonding material and bonded to the existing base.