Ok, so our summer hasn’t been much of a scorcher so far but we are still busy working on a number of exterior lime render jobs. With warmer and longer days it is the ideal season to apply lime render notwithstanding the rain (not so great), so our current July temperatures are good for allowing the lime mortar to dry effectively as high air temperatures or direct sunlight force dry the mortar causing shrinkage and cracking. Certainly the scorching hot days aren’t the best and moving into autumn, by the end of October the lime season is over as it shouldn't be used below temperatures of 5 °C and needs to be protected from freezing for three months. In short, there is a very limited window for getting this particular job done.
Here is a current project, a lovely farm cottage near Northallerton that had been stripped of it's previous cement render . Lime has distinct advantages over cement based alternatives for external rendering of traditional properties as it less dense and more vapour permeable than cement based materials meaning it doesn't trap water and cause dampness within the building, the leading cause of decay in old properties.