Sealant system for chlorinated water pools

A method for adhesively sealing a joint or a surface in or on a building structure that is in contact with chlorinated water, comprising the steps:

• a) applying a primer composition P onto the surface or into the joint to be sealed;
• b) waiting for primer composition P to be cured;
• c) applying a moisture-curable sealant composition S onto the cured primer composition P, thus sealing the joint or the surface;
• and
• d) curing the moisture-curable sealant composition S by means of moisture;
• wherein
• said primer composition P comprises:
• at least one polyol and at least one polyisocyanate, or a polyurethane reaction product thereof,
• at least one organic solvent;
• and wherein
• said moisture-curable sealant composition S comprises:
• between 10 and 60 wt.-%, based on the total composition S, of at least one organic polymer having hydrolysable silane groups,
• optionally up to 30 wt.-%, based on the total composition, of at least one plasticizer,
• optionally between 0.1 and 5 wt.-%, based on the total composition, of at least one monomeric or oligomeric amino-functional alkoxysilane,
• at least one silane curing catalyst.