What kinds of sealants can we use in the joints of factory floors? We need something that won't get tracked and smeared all over the floor but that is easy for maintenance men to install.
Requirements may differ, depending on the width of the joint and what kind of traffic moves over it. One of the characteristics common to most floors, however, is that they are not subjected to wide temperature changes that cause large movements opening or closing the joints. Once floors have cured and dried most of them do not undergo further wetting and drying and the movements that result. Consequently sealants in floors do not usually have to accommodate large or frequent movements as they do in exterior walls or pavements. One of the best materials to put in joints is lead. It can be used either in the form of several thin strips applied side by side on edge, or as bulk lead melted and poured into the joint. If the floor is subject to heavy steel-wheeled traffic that might break unsealed joint edges the lead should be brought about 1/8 inch above floor level and battered over by hammering. Another kind of sealant that is easy to apply is a premolded neoprene compression sealant. This is a tube with parallel sides and internal cross-membranes. It is purchased in a size slightly larger than the width of the joint. It can be installed by compressing it and slipping it into the joint with a lubricating adhesive. The amount of compression should be enough so that even when the joint reaches its widest opening the seal remains in compression, thereby excluding debris. It is easy for maintenance crews to install but it does not give support to the joint edge as does lead. Bulk sealants of polysulfide or polyurethane are long-lasting materials that may be useful in some circumstances. They require careful mixing and more work to install than neoprene compression sealants. Like compression sealants they do not give support to the joint edge.