Epoxy and polyurethane are both resins; generally, they are two component formulations. The mixing of the parts for each resin type creates the fabric with the requisite properties for crack repairs.
Epoxy’s elements are a resin and a hardener; blended together earlier than a crack injection. The combo ratio is typically parts epoxy to one part hardener. Injection epoxies typically cure within three to 4 hours. As soon as cured, epoxy has a robust bond and a hard plastic-like texture.
Polyurethane, while not necessarily a element blend, typically has ; one is the resin and the other is an accelerator. Unlike epoxy, the feel of cured polyurethane varies significantly; one can’t generalize relating to the properties of cured polyurethane.
Differences in The Epoxy and Polyurethane Crack Injection Processes
There are significant differences in how polyurethane and epoxy crack injections are carried out. Epoxy injections are referred to as “Surface port injections” because they involve the use of injection T-Ports to inject the epoxy into a crack.
Polyurethane injection involves much higher injection pressures utilizing packers inserted into drilled holes through the crack in the poured concrete foundation. Like epoxy, the injected polyurethane fills the crack by way of the whole thickness of the foundation thereby stopping water from coming into the crack. Professional polyurethane crack injections typically contain a flushing process to clean the crack to improve adhesion within the crack.
Advantages of Epoxy Crack Injection
1. The tensile energy of cured epoxy is bigger than that of poured concrete. Under stress, cured epoxy crack repairs will not yield.
2. Epoxy injections provide positive confirmation to the injection technician that the crack has been utterly filled.
3. Epoxy crack injections are extraordinarily reliable on account of their low failure rate.
4. Epoxy’s curing time permits the epoxy to gravity feed within the crack, thereby filling all parts of even the finest cracks.
Advantages of Polyurethane Crack Injection
1. Polyurethane can be used regardless of the crack condition and the weather. It doesn’t matter if the crack is actively leaking, stuffed with mud and/or mineral deposits, or if it is small or large.
2. Polyurethane injection includes a crack flushing process that cleans out the crack previous to the injection.
3. The chemical enlargement of the polyurethane will fill voids within the concrete.
4. The speedy curing of polyurethane is helpful when rapid waterstopping is required.
Disadvantages of Epoxy Crack Injection
1. Moisture adversely impacts the adhesive qualities of the anchoring epoxy used to adhere the T-Ports onto the crack. Without sufficient adhesion, the anchoring epoxy will not withstand the injection pressure.
2. Epoxy is inappropriate for re-injecting beforehand injected crack repairs that have failed.
3. Homeowner basement leak repairs with hydraulic cement or caulking render epoxy injections inappropriate because there isn’t any longer surface access to the crack, mud and/or mineral has constructed-up within the crack, and the concrete round parts of the crack is often damaged by water saturation.
4. The curing time and the available viscosities of epoxy are positive attributes, but in addition weaknesses. Epoxy crack injection depends on the containment of epoxy within a crack until the epoxy has cured. This containment uses the compacted soil against the outside wall. Poor compaction, air-hole membranes and the usage of epoxies with insufficient viscosity will end result in the bleeding of epoxy into the soil.
Note: The sturdy epoxy bond is commonly cited as a negative attribute of epoxy crack injections because of its rigidity. Keep in mind that all the poured concrete foundation is rigid; subsequently, the need for flexibility in the material used to inject a crack, in my opinion, is illogical as there isn’t a real need to accommodate crack movement.