[header] How to remove mastic [title] Soak the mastic in hot water. [step] This will only work on some types of mastic, usually in recent homes. It's worth trying first, as wetting the mastic can make other methods safer. 
You should notice the mastic loosening within 20 to 60 minutes. [substeps] Mix the hot water with vinegar or citrus degreaser for extra strength.