Grout is the material that is used to fill the space between the gaps and provide support to the joints of tiles, marbles, granite. Grout can also be used to stop water seepage from cracks, to fill voids under slabs, concrete joints, or honeycombs, or walls. It is visible and can be water-resistant. There is various type of grout material, such as cementitious grout, epoxy-based grout, liquid based grout, and polyurethane (PU) grout.

Polyurethane (PU) grouting requires a specific technique to stop water seepage from cracks, to fill voids under slabs, concrete joints or walls that are caused by water damage. The procedure involves injection expanding polyurethane into the crack-lines or gap created by the water damage. This method is effective to stop the leakage. PU Grouting is most cost-effective and long-lasting repair solution. It provide a non-hacking, non-messy, non-dusty solution to your house and will complete the repair within a day or two.

PU Grout Guide Involvement

Polyurethane (PU) grout, involve injection expanding polyurethane into the space created by the water damage. This method is effective on water leakage area, chemical reaction occurs when the resins contacts with water. The material formulation, grout/water combination forms a gel or closed cell foam. The foam created can be flexible and resilient (hydrophilic) or ridged, the cell structure of the foam crushes when compressed (hydrophobic).

In most scenarios, the water flow or leak can be used to pull the grout into the structure. A hole is drilled in the vicinity of the leak and the chemical grout is injected through the wall into the water source.  The expansion foam will drive through the structure to seal the defect crack lines and joint the gap and all types of concrete structure; therefore, it creates a permanent seal.

Many products will temporarily fix a leak, but if applied correctly, most polyurethane grouting repairs are permanent. The properties of each type can be used to reduce the cost of installation and improve the quality of the repair in long term.  This material is flexible and resilient and allow movement to occur in the structure without damaging the initial seal. It will also trap water in the pores of the wet concrete. PU grout is low viscosity and permeates loose and non-consolidated soil readily. Moisture permeates the tiny breaks in the concrete substrate and climates enlarges the crack lines by expansion/contraction weather in Singapore. PU Grout act as a foundation stabilises, any movement can cause the rigid concrete substrate to separate these tiny breaks in the concrete and enlarge the gap.

PU Grouting Steps

Types of PU grouting method are low-pressure injection and high-pressure injection. The effectiveness of polyurethane foam injection allows liquid polymer to inject into the crack. This applicator can assure that the crack has been saturated with the liquid polymer up to the point when liquid begins to collect at adjacent surface.  The repair of the concrete structures is accomplished using injection with liquid polymer which harden when dry.

High pressure injection is used where a high volume of water flow takes place such as basement, roof, swimming pool and pathway.

A hole is drilled into the lower floor ceiling, and the PU grout is injected through this hole using either low or high pressure (depending on the type of ceiling structure). Once injected, the grout will expand to fill up the void or cracks caused by water damage.

Polyurethane foams are classified as hydrophilic or hydrophobic. Both a hydrophilic and a hydrophobic react with water that is present in the crack, although they can also be mixed with water immediately before injection. A hydrophilic foam system will entrap any excess water present within its structure during foam formation. Both can be formulated to be flexible, but a hydrophilic system is typically more resilient than its hydrophobic counterpart. Hydrophobic formulation has been introduced as resilient and flexible as a hydrophilic without subsequent susceptibility to shrinkage with time.

Avoid installing gels in expansion joints or cracks that are subject to movement. Gels form a solid material with no cellular structure to disperse tension under compression. This tension can split the gel and damage the seal. These can be the most difficult to repair long term.

In our modern year, grouting will continue to maintain its value as one of the easiest, most cost-effective, and long-lasting repair solutions available.

After knowing so much about PU Grouting, is time to approach SWC Construction to provide free consultation to ensure you a good repair work to ease your leakage experience. Contact us now, we are available to assist you with solution to resolve your waterproofing leakage.