All of our non-hydraulic lime plasters, renders and mortars are produced at our warehouse using a traditional hot lime process. This involves mixing quicklime with sand which is then slaked with water, a reaction which produces intense heat. Historically, the majority of mortars would have been made in this way, meaning hot lime mixes will more closely replicate historic mortars. In years gone by the mortars would have been mixed in situ and used hot. However, allowing the material to cool doesn't lose any of the performance benefits.

Benefits of Hot Lime Mix

There have been many trials and discussions recently on hot lime processes and many in the field now advocate the advantages of a hot lime mix over previous methods of mixing matured lime putty and sand.

High Free Lime Content

One main reasons may be the ratio of sand to lime in a mix. Generally this has been 3:1 sand to matured lime putty. However, using this ratio with a hot lime mix equates to 2:1 as the quicklime expands during the slaking process. Therefore, a hot lime process increases the amount of free lime content in the mix. This produces a stickier mix and a very workable material which adheres well to brickwork. 

Flexible and Vapour Permeable

Hot lime mortars will produce a weaker and more flexible set. A weaker set is preferable for soft bricks as it allows moisture out as well as accomodating any movement. Previous hard cement mortars have allowed fractures to penetrate into the brickwork.

Coarse, Medium and Fine

Our hot lime mixes are available as a coarse, medium or fine grade and can be used as a mortar, render or plaster. Our hot lime mortars are available in a chalk white or oatmeal colour. The colour is determined by the sand and aggregates used.