Caulk and foam sealants can be used to make windows and doors airtight, and to stop water seepage around tubs, toilets or sinks. There are several different types of sealants including silicone caulk, mastic sealant and rope caulk. Silicone caulk is a sealant that can be used both on the interior or and exterior of any home or building for weatherization purposes. It bonds well with most materials, and is typically clear or white in color. Putty-like rope caulk is typically used for sealing drafts in windows and is sold in long rope rolls which can be cut to a desired length. By using caulk and foam sealants, you can save on electricity bills by preventing warm tempered air from seeping outside. Sealants can also aide in water saving by keeping water from leaking from tubs and toilets.