High pressure polyurethane (PU) injection grouting involves the process of injection polyurethane into the substrate with high pressure so the cracks and voids in the substrate can be filled with the waterproofing slurry to stop any potential water seepage. It is a very common waterproofing method that is widely used by specialist contractors to repair water leakages, generally through concrete substrates.

When do we need a PU Grouting?

When there is damaged concrete, when there are deep holes in wall, cracks in concrete floors, basement, swimming pools, side walls or even pipes and sewer lines. These are properly identified by SWC Construction engineers with a thermal waterproofing method to provide scientific information to justify our repair method to perform a PU Grouting method.

These are the 5 steps taken to carry out PU Grouting:

Here are the general steps to carry out high pressure polyurethane injection grouting:

1. Drilling and inserting of injection ports

   1. Our waterproofing specialists will first drill holes into the leakage areas, usually cracks and voids and insert and tighten a metal injection port into the cored hole

2. Protection of work areas

   1. PU injection grouting is a non-invasive method of repair and is relatively clean. However there may be some dust and spillage of the grout material during the work itself. Hence proper protection using plastic sheets and cloth is very important.

3. Grouting using a high pressure grouting machine

   1. The specialist will use a high pressure grouting machine to inject the PU grout into the concrete via the injection ports. Each injection port must be injected individually twice to ensure properly coverage of the grout material.

4. Removal of injection ports & sealing up

   1. After the grouting process has ended and grout has dried, the injection ports must all be removed. Once the injection ports have been removed, it is important to seal up the cored holes with waterproof cement compound.

5. Ensure no leakage

   1. Check after check after check. Ensure that no leakage on affected damaged area.

PU injection has many advantages as compared to other methods of waterproofing. Polyurethane is a fast drying resin that dries up in less than an hour upon contact with water or moisture. A normal residential repair can be completed within a day, this allows repair works to cause minimal disruption and inconvenience. Furthermore, PU injection is a very effective method to repair water leakages and it has a very good lifespan. Because of the strong adhesiveness property of polyurethane, it can form a very strong bond with the concrete or cement surfaces and can last many years. PU injection grouting is also a non-invasive, no hacking method of repair.