The main reason for using a polyurethane sealant is to provide movement when applied in gaps and joints and this is why they are elastomeric and offer +/- 25% movement capability. Sealants are not adhesives but need to have sufficient adhesion to the substrate to remain bonded over their expected life of service.
Polyurethane sealants are classified in two types based on their technology: one-component polyurethanes and two-component polyurethanes.
One-Component Polyurethanes:Single component sealants are moisture-cured and do not need to be mixed with anything prior application. The required temperature for application is 41°F to 95°F (5°C to 35°C) with a relative humidity of 40-70%. Lower temperatures combined with low humidity will extend the curing time. Mapeflex™ P1 is a non-sag version for vertical applications and Mapeflex™ P1 SL is a self-leveling version for horizontal applications.