New, Remedial, Residential & Commercial Waterproofing Optimal Seal prides itself on being versatile across Sydney & the Greater Region. We have and continue to accomplish works across commercial & residential. With extensive knowledge of all aspects of waterproofing and an impeccable record of no leaks, we undertake all size jobs of both remedial and new works. No waterproofing systems are out of our reach. Optimal Seal have never had a warranty issue. We conduct our services to the highest of standard complying with all manufacturers and Australian standards. Our Services Waterproofing Sheet Membranes External/Rooftops Internal Wet Areas Crack Injection Flood & Dye Testing Underground Works Concrete Crack Injection Optimal Seal are specialists in Polyurethane Concrete Crack Injection with over 15+ years experience. Our team conducts all works whilst exercising the highest levels of safety standards. Crack Injection is an effective option for repairing minor to major structural & non-structural concrete cracks, which in turn prevents the onset and deterioration of concrete spalling or concrete cancer. Our systems are designed to repair water penetrating cracks to sub-basement walls, floors, suspended slabs, concrete pools, water tanks, retaining walls and almost all other leaking concrete substrates. Remedial Building Works Demolition Surface Preparation Waterproofing Tiling Connect with us!