Salt removal & desalination

Remmers Desalting Compress is a capillary-active poultice of active mineral constituents and cellulose for non-destructive reduction of soluble salt content in masonry, brick and stone, to WTA Code of Practice 3-13-01. Mixed with water and applied wet over the salt-affected substrate; as it dries, salt-laden pore water migrates into the more capillary-active compress where the salts crystallise, and the spent compress is removed mechanically. Multiple cycles may be required on heavily contaminated masonry. Desalting precedes renovation (WTA) plaster or breathable render. CONFIRM mix ratio, layer thickness, dwell time, number of cycles and current AU pack with Remmers Australia.

Westox Cocoon is a desalination poultice for salt removal from masonry, brick and stone, used to reduce chloride and sulfate salt concentrations in walls affected by rising damp, marine exposure or historical salt contamination before renovation plaster or coating. Applied wet, it draws soluble salts into the poultice as it dries and is then removed with the extracted salts; multiple applications may be required. Westox is an Australian supplier (Westlegate Pty Ltd). The product page does not publish composition, coverage or cycle detail — CONFIRM with Westox technical.

The traditional conservation method for desalinating brick and stone is a site-mixed poultice of fine clay (sepiolite or attapulgite) and/or cellulose (paper-pulp) fibre — sometimes with talc, chalk or lime — applied wet to the salt-affected surface. As it dries it draws salt-laden pore water outward by capillary action and the salts crystallise within the poultice rather than the masonry; the dried poultice is then removed. Effectiveness depends on matching the poultice pore size to the substrate. Used in heritage / conservation work before renovation plaster or lime render reinstatement. Pre- and post-treatment salt sampling is recommended.