Demista Pads are simple efficient ultra slim heating pads that fit inconspicuously behind bathroom mirrors; existing or newly installed. Once fitted the mirror will never steam up in and around the pad. Look for the Demista sign to ascertain the correct size for the mirror of your choice. Frequently Asked Questions. Can demista be cut? No. This will damage the insulation rendering it dangerous. How much of the mirror should demista cover? This depends on what area is required to be clear. The area of the mirror that will remain steam free is the area of the demista pad plus approximately 20-30 area around it. Can demista be used with safety backed mirrors? Yes but the backing should be earthed as should all metal parts surrounding the mirror. Is a transformer required? Only with low volt models. Can more than 1 demista be fitted to a mirror? Yes within the limitations of the available power. They should then be fitted in parallel. What adhesive should be used to bond the mirror to the wall? Any solvent free. Can the mirror adhesive be applied across demista? Yes. Can demista be used with a dimmer switch? This is not advisable as when turned down there would be insufficient power for emista to be fully effective. What thickness of mirror can be used? As glass is a good conductor of heat emista is suitable for use with any normal thickness of mirror. All HIB products are delivered especially and directly to you by an HIB factory driver. This treatment is the reassurance you need when ordering an item as your choice will be transported by a purpose-built van that is ideal for the safe transit of such delicate goods.