COATING – A protective layer on and above the surface. Specifically, a material applied to a surface by brushing, dipping, mopping, spraying, troweling, etc., to preserve, protect, decorate, seal or smooth the substrate.

EPOXY INJECTION – A process similar to pressure grouting. The epoxy can be injected at various degrees of viscosity, depending upon the conditions. Epoxy injection is a bonding process used to repair a wide variety of concrete and masonry structures. The material not only fills cracks but welds them together structurally with an epoxy that is forced through the crack to form a strong bond.

GUNITE – A dry mix of cement/aggregate blend which is mechanically forced through a hose. At the nozzle, water and additives are added to the mix before it reaches the substrate.
Trade name for a construction material composed of cement, sand, crushed slag and water mixed together and forced through a cement gun by pneumatic pressure; used to stabilize slopes; the method of applying dry-mix shotcrete through a hose using compressed air.

MUD JACKING – A method of horizontally lifting a sinking concrete slab. This long-standing method is done using dirt or clay mixed with water. A hole is bored through a concrete slab which has sunk. The mud jack, which is housed on a truck with a slurry mixer, is connected to the hole by flexible pipe. The mud jack then forces the mix under the slab and elevates it.

PENETRATING SEALER – A water or petroleum-based material, applied as a liquid, which carries molecules into the substrate.

PRESSURE GROUTING – A process through which a liquid mortar is mechanically forced into voids or cracks. The mortar can be water- or petroleum-based products such as epoxy.

SEALANT – Often referred to as caulk, used to seal out water and/or air. Various types of sealant are available, depending on the type of substrate and conditions. 1. A material used for sealing spaces between materials. 2. An elastomeric material that is used to fill and seal cracks and joints; at expansion joints, this material prevents the passage of moisture and allows horizontal and lateral movement. 3. A caulking material used to fill voids or seams for acoustical, air infiltration, or thermal purposes. 4. A mixture of polymers, fillers, and pigments used to fill and seal joints where moderate movement is expected; it cures to a resilient solid.

SHOTCRETE – A wet mix of cement/aggregate blend which is pressure-sprayed, by air or mechanical pump, through a hose onto the substrate. Mortar or concrete conveyed through a hose and projected at high velocity onto a surface; also known as air-blown mortar; pneumatically applied sprayed mortar or gunned concrete.

SLABJACKING – A newer method of concrete slab lifting, similar to mud jacking. Instead of clay or dirt, the material forced under the slab may contain various degrees of cement plus sand aggregate.

SUBSTRATE – A surface upon which other materials are applied, such as paint, flooring, or roofing. The underlying support for ceramic tile or other finish-type installation.