Polyurethane Injection Used for Basement Leaks

Polyurethane injection is arguably the most common type of injection used for repairing a basement leak and waterstopping generally, due to its versatility. It is used exclusively for stopping leaks in poured concrete foundation walls and structures. When a leak repair/waterstopping is required in subway tunnels and mineshafts, the cracks and rock fissures are injected with polyurethane (also referred to as grout). Under certain conditions epoxy crack injection is a viable alternative to polyurethane crack injection.

Polyurethane injection involves the high pressure (typically 1500-3200 psi) injection of activated polyurethane through injection packers hammered into drilled holes into the leaking poured concrete structure. Like epoxy, the injected polyurethane travels through the entire thickness of the foundation wall (typically 8") thereby preventing water from leaking into your basement.

Installed Injection Packer	Polyurethane Crack Injection in Progress	Evidence of Polyurethane Travel Through Wall

Polyurethane Injection Video

Watch a polyurethane crack injection being performed

Polyurethane Injection Applications for Basement Leaks

• Actively leaking cracks;
• Cracks in wet or damp basement walls;
• Previously repaired cracks (internally and/or externally) that are leaking; Note: an epoxy injection is not appropriate for use in repairing a failed crack injection;
• Cracks full of mud or mineral deposits;
• Cracks caused by corroding reinforcing bars (typically in reinforced concrete slabs);
• Leaking forming tie-rod holes;
• Leaking forming snap rods;
• Leaking I-beam pockets;
• Leaking underground structures in general (such as parking garage cracks and seams);
• Underground pipe penetrations in a wall to accommodate electrical conduits, gas lines, air conditioning lines and pipes;
• Expansion joints;
• Honeycombing;
• Pool bottoms (when access is possible);
• Seams created by a cold pour;
• Overhead concrete structures; and
• Gaps beneath the window frame and the top of the concrete wall cut-out.

Images of Typical Polyurethane Injection Applications

Actively leaking crack	Failed crack injection	Previously repaired crack
Large foundation crack	Crack with mud and mineral deposits	Leaking forming tie-rod holes
Leaking tie-rod hole	Corroded snap rod	Leakage through i-beam pocket
Leaking pipe penetration	Leakage through honeycombing	Pool bottom waterproofing
Pourous poured concrete

The Attributes of Polyurethane Resin

From reviewing the typical applications above, it is clear that polyurethane injection is an extremely versatile waterproofing method that can be used to deal with any basement leak in a poured concrete structure, under all conditions. This versatility is attributable to the characteristics of our polyurethane resins which are:

• Our activated polyurethane typically expands to 2.5 times it's volume; this is very desirable when filling large cavities or when the size of a cavity is unknown (as in the case of honeycombing);
• The expansive force of polyurethane is significant; consequently, it will fill any and all gaps that it encounters - this is particularly useful when dealing with very porous concrete or when dealing with honeycombing. It will also expand wherever it can; following the path of least resistance, it will fill any and all voids encountered;
• Our polyurethane resins are non-toxic. This makes them suitable for use with potable water systems such as cisterns;
• Polyurethane sets rapidly in the presence of hydrogen. Since hydrogen molecules are a component of water (H2O), the presence of water during an injection actually increases the reactivity of the polyurethane. This makes polyurethane the ideal product to use when active basement leaks and/or significant hydrostatic pressure, are encountered;
• The polyurethane resins that we use will not freeze and always remain flexible (not an attribute of all polyurethanes); this is desirable when the concrete surrounding it expands and contracts due to thermal cycling;
• Polyurethane sets very quickly. This is essential in stopping leaks where significant hydrostatic pressure is present;
• Polyurethane injections are conducted using hydraulic hoses which are crucial when accessibility to the repair area is limited; and
• At AquaGuard Injection & Waterproofing® we use polyurethane resins of varying viscosities; this gives us the ability to deal with any underground leak situation, from hairline cracks to large voids.

Note 1: Several technical factors need to be taken into account to determine whether a basement leak should be injected using epoxy or polyurethane; for example, the effects of tension and compression at the crack location must be factored into the decision on how best to deal with your leak repair. Their is alot of science behind injection repairs; trust our trained technicians to determine whether polyurethane injection is optimal for your circumstances.

Note 2: Not all Waterproofing Contractors offer polyurethane injection basement leak waterproofing repairs. Why? Because it takes training, skill, knowledge, high quality polyurethane formulations, professional injection equipment and determination to perform a successful polyurethane injection; otherwise the injection will likely fail. As significant training and a commitment to work excellence is crucial, many companies shy away from polyurethane injections because they cannot reliably produce successful results. The demanding nature of polyurethane injection is so significant that some of our competitors call upon us to perform their warranty repairs!