The new mortar must match the historic mortar in color, texture and tooling. The sand must match the sand in the historic mortar.
Lime mortar is stored in mounds at the site.
The maturing period for the lime mortar is 6-9 days. The top layer of the mortar, which has hardened is scraped and the mortar from the inner core is removed to be remixed before use. Once lime and sand mortar is mixed and applied on a wall, it begins the process of carbonation, which is a very gradual process . If lime mortar is left to dry too rapidly, carbonation of the mortar will be reduced, resulting in poor adhesion and poor durability .