Lime mortars offer advantages over cement based mortars, particularly in the repointing of historic masonry. First and foremost, lime mortars were the mortars used in the construction of many buildings built before the 1920's, and almost all buildings before the 1880's. They are generally less hard and more vapor permeable, allowing moisture levels in the wall and reduce the amount of soluble salts in the stone or brick faces. Lime mortars should be viewed as a sacrifical material and one of the functions of mortar is to allow moisture to migrate out of masonry through the softest point. When you are working with lime mortars, the mortars are the softest point,    however, if buildings are repointed with cement based mortars, often the masonry (i.e. brick or    stone) is the softest point. If mositure is retained within the building fabric, the fabric may be    exposed to damaging freeze thaw cycles, which could cause greatly accelerated deterioration    and decay.

   Preparation:
Any existing defective mortar or pointing should be removed to a depth of at least one and a half times the width of the joint, (remove all friable material) but not less than 3/4 to receive the new mortar. Perpared Joints should be as clean as possible, existing mortar should be cleaned from the edges in the joint to ensure proper bonding between masonry unit (i.e., brick or stone), and the back of the joint should be square to receive the mortar.
Any existing cement mortar must be carefully removed. If necessary, horizontal cement joints may be raked out by carefully scoring the center of the mortar joint with an angle grinder to relieve the stress on the joint. Angle grinders should only be    used by highly skilled masons and should not be used on head joints as theres is a greater    risk of damage to the masonry. The remaining mortar in head and bed joints should be    removed 8to the required depth using hand or pneumatic stone carving chisels. Do not grind    mortar from any surface of the host masonry. Raking out shall leave a clean, square face of    sound mortar at the back of the joint, and clean masonry surfaces. Mortar joints should not    be shallow or feather edged.
             Existing historic lime-based mortar shall be removed by hand.    Use only hand or pneumatic stone carving chisels that are no wider    than one half the widths of the existing masonry joints.
           Do not widen the existing masonry joints by damaging    masonry units. Do not spawl or chip the surrounding masonry edges    in the process of mortar removal.
           Remove debris from joints by brushing joint faces, vacuuming,    or blowing with pressurized air. Joints may be rinsed using very low    pressure spary asmbly with caution. Verify that water will not migrate    to other areas and cause damage. Ensure that all surfaces below    rinse areas are wet prior to cleaning out joints so as not to cause    staining of the masonry fabric.

   Damping:
            After the preparation of the mortar joints, the prepared area must be rinsed down with water removing all excesses of mortar and just from the joints, being careful not to saturate the masonry, but to dampen and clean out the joints. The idea is to control the absorption rate in the wall and to promote the slow curing of the mortar that is being replaced. If the host masonry is not thoroughly dampened the brick or stone could pull the moisture too quickly from the mortar which could cause shrinkage cracking, lack of bonding, and loss of strength. Depending on the type of brick or stone wall being pointed and the amount of area cut out and rinsed down you may have to re-dampen the wall before pointing. Misting with spray bottles or garden sprayers prior to pointing in that area is also a good way to keep control of the wall area being repaired. The mortar should be as dry as is practicable to point with, but moist enough to achieve any joint details required. This allows maximum compaction in the joint, which reduces shrinkage cracking and reduces the tendency to smear on the masonry surface.

Comfort Levels:
            As a good rule of thumb; if the mason is comfortable then the wall is comfortable. On hot days where accelerated drying may be an issue make sure the wall is well protected by shade cloths, or tarps, keeping attention to the absorption rate of the substrate. Mist as necessary to slow the drying, but still allow the material to cure. Protect all work from harsh drying winds or direct sunlight which could cause "flash curing", and from driving rain and frost which could casue mortar failure. Continue to wet the damp burlap periodically as needed. One good method of protecting the wall and promote good carbonation is not to drape the walls from the surface to the damp cloth of burlap. This provides a good moist condition to slow the drying process, enhance curing, and maintains good air circulation for carbonation.

Pointing:
            After removal of the defective mortar and damping of wall, the wall is ready to start pointing. Fill out all major voids or relaying of brick or stone leaving the finish joint back about 1 1/2 times the width of the joint, this is usually about 3/4 to 1 1/2 of an inch back from face of the masonry (ensure that all friable material has been removed). Then point in lifts of approximately 1/4 or 1/3 lifts at a time to replace the mortar if using a traditional Virginia Lime Works Wood Fired Lime Mortar. Mix&GO Premium Pre-Mixed Lime Mortar can be installed in lifts of 3/4" at a time. Maintaining an even amount of pointing helps to keep the consistency of replacement mortar the same and curing of the wall should come about in an equal and even fashion. The tooling of the finish joints should be determined and specified. Please see our "Joint Finishes" Gudielines. Keep in mind that is often beneficial to tool new work to match existing joints on the sturctures whereas the original joint profile could be lost forever. Some tooling may be different from one location on a building to another, being either face work or backup work. The joint details from front facades to side or rear elevations may change, so be aware of existing evidence for making the proper determination of which technique should be used.
       One method that can be used in pointing is to slightly reveal or trim back the mortar from the face edge of the brick or stone to detailing that unit. Keep the joint contained on the inside and do not let it come out to the outside of the brick. In keeping the joint contained it makes a much more attractive wall and when viewed from a distance the wall will blend together where existing joints have weathered and already are somewhat revealed.