The present invention relates to a process for producing a polyurethane sealant, which comprises mixing (a) polyisocyanate, (b) polyetherpolyols, (c) aliphatic, exclusively amine initiated alkoxylation products having an OH-number of 400 to 1000 mg KOH/g and a functionality of 4, (d) blowing agents and optionally (e) chain extenders and/or crosslinking agents, (f) catalysts and (g) auxiliaries and/or additives to give a reaction mixture and reacting the reaction mixture to give the polyurethane sealant. The present invention further relates to a cast in place polyurethane sealant, obtained according to a process according to the present invention.