Construction adhesives can be further defined by the materials, or substrates, to be bonded. To start a bond the process of adhesion must occur by chemically, mechanically, and/or physically adhering material to the substrates. Adhesives used in construction are classified by function into two broad categories, structural and non-structural.
Structural adhesives are used to bond materials which must withstand loads or stresses acting to compromise structural integrity. Plywood laminate glues and epoxy used to put mounting bolts into concrete are typical examples of these bonding systems.
Non-structural adhesives keep decorative or protective materials in place such as tiles, laminates, floor coverings, millwork, and other elements that are not subject to critical stress. Clearly to prevent disaster the distinction between these two categories must be considered prior to selecting an adhesive for engineering applications.
A typical categorization of adhesives based on substrates would be:
Smooth surface contact requiring minimal adhesive thickness: includes hard, finished, and impervious substrates such as dense concrete, plastics, metals, hardwood, glasses, etc. Chemical, heat, or radiation reactive components adhere to the substrate without need for solvent evaporation or absorption. Chemical and/or physical changes then occur to build cohesion. Examples include epoxies, thiokols, thermosets, RF and UV activated, and some humidity activated adhesives such as certain silicones and polyurethanes.
Rough surface contact requiring greater adhesive thickness: includes permeable, absorptive, and unfinished substrates such as softwood, bricks, lightweight concrete, joints, and seams. Solvent based solutions, emulsions, dispersions, and other similar adhesives are used which have a low viscosity carrier to promote adhesion. The carrier then reacts, evaporates, or is absorbed by the substrate to build cohesion. Examples include acrylics, mastics, pressure sensitive formulations, cements, mortars, PVC resins, some silicones, and certain foaming polyurethanes.
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| Photo from Vital Technical |
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| Photo from Vital Technical |
RECOMMENDED FOR:
Bonds to a large variety of building materials. Use for installing metal and wood studs or strapping to concrete, wood furring strips to concrete floors for carpet installation, mounting panelling, and vinyl cove base.
NOT RECOMMENDED FOR:
Polyethylene or polypropylene; continuously wet areas or water immersion.
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