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*Question & Answer Epoxy*

Dear Bob

Thank you for your very informative web site. What is the difference between epoxy injection and polyurethane injection? Is one of them better for basement wall cracks? When would you use one over the other?

Dear SB

Epoxy injection has the advantage of welding the concrete back together and giving the concrete back its original design properties. In other words, once you inject a crack, it is as if the crack had never happened. Its repair is structural and a waterproofing. Urethane does not weld the concrete back together. It does stop the leak however. As a matter of fact, it has the capacity to stop the leak as the water is still flowing through it. This is possible with epoxy, but is much more complicated, and difficult to do. I use epoxy injection whenever I am trying to restore a damaged structure. If I am trying to cut off water flowing through an expansion joint, or where concrete has been poured in multiple pours and never intended to be monolithic, then I use urethane. For most basements, epoxy injection is the best solution for cracks in the walls or floors. If you are injecting the joint between the floor and the wall, either system can be used effectively.

Dear Bob

Is there an epoxy that will bond all materials together?

Dear MJ

There are many different kinds of epoxys for many different applications. Epoxy will bond woods, aluminum and glass well. It does not bond to Teflon, polyethylene, polypropylene, nylon, or Mylar. It bonds poorly to polyvinyl chloride, acrylic and polycarbonate plastics. The only way to tell if an epoxy will bond to a material is to try it. Generally, epoxy adhesives are the best choice for bonding dissimilar materials together. If epoxy bonds to Material A and to Material B it will bond the two materials to each other. The best thing to do is to try it and see for yourself.

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