Abstract: In a process for producing a composite element having at least a covering layer and polyurethane foam, the covering layer is inserted into a mold and a polyurethane reaction mixture is introduced onto the covering layer. The polyurethane reaction mixture is reacted to form a polyurethane foam, wherein the polyurethane reaction mixture is obtained by mixing a) polyisocyanate with b) compounds having isocyanate-reactive OH groups, c) blowing agents including water, d) thickeners and e) catalysts. Bis(N,N-dimethylaminoethoxyethyl) carbamate, N,N,N-trimethyl-N-hydroxyethylbis(aminopropyl ether), N,N,N-trimethyl-N-hydroxyethyl(aminoethyl ether) or mixtures thereof and/or tetramethyldiaminoethyl ether are employed as catalysts and the polyurethane foam has a density of not more than 200 g/dm3.