The interior of the home are mainly our concern when we conduct maintenance, repairs and renovation. But let us not limit ourselves to these things only because as much as we need interior maintenance, exterior maintenance is essential as well.
“Roofs may be classified as flat roofs (less than 10 degrees slope) or pitch roofs. Although some roof systems require less maintenance than others, all roof systems should be checked periodically to ensure that they are free of debris and that the drainpipes are clear.”
Read here: http://www.bca.gov.sg/myhomeeservices/HomeOwners_Maintaining_Maint_RoofTips.htm