Salts of alkyl-2-benzimidazole-carbamate and fungicidal compositions thereof suitable for paints and plaster

A fungicidal composition comprising an effective amount of a water insoluble compound of formula I ##STR3## wherein R.sub.1 is an alkyl group having 1 to 4 carbon atoms and R.sub.2 is a straight-chain or branched-chain alkyl group having from 10 to 16 carbon atoms, a suitable insert carrier and an effective amount of an algicide selected from the group consisting of tetramethylthioramidisufide, N-trichloromethylthiophthalimide, 1-butyl-(carbamoyl)-2-benzimidazole-carbamic acid methyl ester, 2-rhodane methylthiobenzthiazole, 2-(thiazolyl-(4))-benzimidazole, dodecylguanidinoacetate, N-dichlorofluoromethylthio-N',N'-dimethyl-N-phenylsulfuric acid diamide, 2-cyano-N-(ethylaminocarbonyl)-2-(methoxyimino)-acetamide, N-(propyl)-N-(2,4,6-trichlorophenoxyethyl)-N'-imidazolyl-urea, 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea, 2-methyl-thio-4-t.-butylamino-6-cyclopropylamino-s.-triazine, 2-n-octyl-4-isothiazoline-3-on, 2-cyclohexyl-4-isothiazoline-3-on, 2-dodecyl-4-isothiazoline-3-on, 2-benzyl-4-isothiazoline-3-on and dithiocarbamates and the manganese and zinc salts of said dithiocarbamates.