Pressure grouting involves the process of injecting a grout material into areas with voids and pores to fill up these voids and pores with the grout material. There are many types of grout material and polyurethane (PU) is one of them. Polyurethane grouts are specifically engineered to react with water and expand in volume to form a hydrophobic and impermeable layer of seal which stops water flow immediately.
Water leakages will only occur when there is first, a breach in the existing waterproofing system as well as faults in the prevalent concrete structure, i.e. cracks. Both factors must be present for a water leakage to happen. Remove any of these two factors and the water leakage will stop.
One method to eliminate the breach in the existing waterproofing system is to hack and re-waterproof the corresponding wet area (roof, toilet, kitchen, balcony etc). This is however very costly and messy. We then look to repair the faults in the concrete structure – PU injection grouting.
The PU grout will first be injected, by a machine operated pump, into the concrete structure. The PU grout will then react with the prevailing water/moisture in the concrete structure and expand up to ten times in volume to form a very strong chemically and mechanically bonded layer of waterproofing membrane to act as a water-stop.
If you see a significantly visible crack line on your leaking bathroom or balcony’s ceiling and water is visibly dripping from the crack line, PU grouting is the most effective and cost-saving solution to repair this leakage problem. It is a common misunderstanding that by conducting PU grouting, it will result in the leakage “shifting” or “moving” to another area. We have previously established that water leakages will only occur when there is BOTH a fault in the concrete structure as well as a breach in the existing waterproofing system, without any of these two defects there will not be any water leakage. PU grouting serves to repair the fault in the concrete structure and repair any cracks and voids. Once all the faults in the concrete have been rectified, the water leakage problem will be stopped.
Furthermore, PU injection grouting is an established method of repair for water leakage issues on concrete structures for more than 30 years. The method has been tested, proven and accepted by many industry professionals and government bodies.