SQ PU Sealant Description SQ PU Sealant is low modulus, one component, class A Polyurethane sealant. When cured it will form a tough, flexible seal capable of cyclic expansion and compression movement of 100% (+ 50%) of original joint width. D+ PU Sealant is virtually unaffected by normal weathering conditions such as rain, sunlight, snow, sleet, ultra-violet radiation, ozone, atmospheric contamination and pollution. Its excellent weatherability enables it to retain its original properties after years of exposure, refer to the.