Prompt is a natural cement, mined and manufactured in Grenoble in France. It is burned at similar temperature to lime and contains nothing more than what is dug from the earth. They are supplied in 25kg Bags.
Lead Mate Sealant
Lead Mate Sealant is specially formulated as an alternative to mortaring lead flashing and sheet into brick, stone and concrete, providing a fully waterproof joint that will not crack or shrink.