Lime mortar repointing is the process of replacing old tired mortar with new. If your home or property is built with a lime mortar it must be repaired and repointed with a lime mortar.
Natural elements and the previous use of cement will play a part in when repointing needs to be considered. When a property's old mortar has done its intended purpose and needs replacing. The telltale signs are the old mortar will have receded and is easily removed from the joints with minimal effort.
Tired lime mortar that has done its job
Early cement damage to soft bricks
Extreme cement damage to soft bricks
Another reason for repointing is if a property has been incorrectly repointed in the past using a cement mortar instead of lime. Modern cement can cause many problems like dampness and brick damage. Using a cement-based mortar for repointing lime-jointed brickwork is unbelievably stupid. These are old walls that will naturally have a certain amount of moisture penetrating them and the lime joints are the only means of that water escaping. The joints are a sacrifial part of the wall that allows any moisture in the wall to escape. If cement is used the water cannot get out through the joints and the whole wall will become damp inside and outside. The bricks will then stay permanently moist, and as the moisture in them freezes and thaws, the face of the bricks will blow.
The repointing process consists of two main aspects, The first is the removal of the old mortar and preparation and the second is the repointing and finishing.
Preparation for Repointing
It's all in the preparation... Removal of the old mortar in preparation for repointing is a crucial part of the process. Irreversible damage can be caused to the bricks if a time-served professional does not undertake the work. Over the years we have seen some shocking examples of permanently disfigured brickwork caused during this process. Unfortunately, this can not be rectified so don't let it happen to you, chose Build Bright with confidence
Old lime mortar removal
We rake out the old soft lime mortar with hand tools, If it doesn't come out easily it does not need repointing! If it is soft and in need of repair we rake out the joints to twice the width of the joint or to we have a solid foundation for the new mortar to bond to.
Cement mortar removal
Cement mortar requires the careful and experienced use of power tools to remove it. This must be done with the utmost care to protect the surrounding bricks. We pride ourselves on this part of the process never causing irreversible damage.
Repointing
The lime mortar repointing process is one that takes more time and attention than cement repointing. The mortar must be of a good consistency and the wall for it to be applied must be prepared correctly. When applying the mortar this must be done with much care and attention to detail. If done incorrectly it could have irreversible consequences leaving bricks stained and unsightly. Our pointing process is of a very high standard using time-served trusted techniques and quality locally sourced NHL limes and local colour-matched aggregates from the Winchester Lime Centre.