The last thing your home needs if for a chimney fire to break out and as such your chimney should be maintained at all times. Cleaning your chimney is not a weekly task that you would need to set yourself to, but it would have to be done when the opportunity presents itself. Similarly chimney flue repair should be done should it be suspected that there is any fault within the flue or the chimney itself. Cracks in the flue need to be covered up as soon as possible and before further use of the chimney as soot, creosote and smoke can be trapped between the flue and the chimney and cause countless problems, the smallest of which could be that the smoke can travel back down the chimney and into your home. This would render your flue useless because it is supposed to lead these impurities out of the home instead of letting it back in.