So you’ve finally found the time to give those concrete cracks some attention. The next move is to decide what material you’ll use to fill them in and repair the concrete surface. The two popular options for concrete crack repair are epoxy and polyurethane. Each has their own advantages and disadvantages. However, epoxy arguably has the upper hand over polyurethane. Read on if you want to know more about why you should choose epoxy or polyurethane for repairing concrete cracks.
Contrast and Comparison
Epoxy and polyurethane are often compared because of the similar characteristics of the two. These include:
- Both feature a two-component formulation. The two components of epoxy are the resin and hardener. These two components are integrated prior to application. The formulation of polyurethane doesn’t necessarily have to be two-component. Otherwise, the resin is blended with an activator or accelerator prior to application.
- Viscosity levels vary. Another similar characteristic that epoxy and polyurethane share is that the viscosity of each varies. This depends on the formulation used for each one.
- They are both referred to as resins. Both epoxy and polyurethane are classified as artificial resins in polymer chemistry.
The main difference between epoxy and polyurethane are recognized in how each one is applied. Here are the differences in how the crack injection process is carried out using the two:
Epoxy – Injecting epoxy in a concrete crack are done at a low pressure (20-40 psi) This is why epoxy crack repair process is commonly referred to as “surface port” or “low-pressure” injections. The duration for curing of epoxy takes more time than for polyurethane. Repairing cracks with epoxy also do not require a flushing process.
Polyurethane – Unlike epoxy, activated polyurethanes can be injected at low pressure or at a high pressure approximately 1500-3200 psi. The curing time is fasters. However, in some instances, the crack needs to be flushed out to ensure optimal adhesion.
So why choose epoxy?
Epoxy offers an advantage you can’t expect from polyurethane. It offers a compressive strength of up to 14,000 psi. This makes it the better and only choice for cracks that emerge from structural damage. Polyurethane doesn’t offer the same advantage of restoring the structural integrity of a concrete crack.
Although polyurethane injections cost less, dry faster and are great for actively leaking cracks, epoxy is a much worthy investment. Especially when considering the long-term durability of a concrete crack. Consult a contractor specializing in epoxy installations and concrete repair to find out more or visit our homepage for epoxy flooring services.