Home / BUILDING SUPPLIES / Insulation / Micafil Vermiculite ( Chimney Fill) Micafil Vermiculite ( Chimney Fill) Stock Status: In Stock Creighton’s of Lisbellaw are proud stockists of Micafil Vermiculite as an ideal chimney fill product. It is a natural, versatile and easy to use material. Email Us Your Enquiry Add to your Wish List Information Creighton’s of Lisbellaw are proud stockists of Micafil Vermiculite as ideal chimney fill. Vermiculite is a naturally occurring mineral which expands at high temperature. The free running properties of Vermiculite make it easy to use. As a fireproof material, Micafil is ideal as filler to insulate around flue linings, behind firebricks and around pipes when fitting stoves. Use Micafil also to fill between brickwork flue and lining.