If you own a home with a stone foundation or with a field stone wall you understand the visual majesty of natural materials sculpted to fit complicated building practices. The different colored stones and or combination of other materials such as granite, brick, marble and concrete can have a textured and often historic look that many people want to preserve. Re-pointing and maintaining these styled walls can keep them lasting for many years to come.
Mortar that was used prior to the 1940s is about wearing thin, if not disintegrated all together by now. Mortar plays a key roll in helping your wall to stay in one solid working structure. Mortar helps to solidify the stones together, filling up the natural gap between materials and helping to keep the interior fill of the stone wall together. Without the Mortar keeping the joints closed the wall may look more natural, however, it looses valuable strength and cohesion, allowing for soil expansion to wreak havoc.
Bowing walls and collapsing wall corners and joints are all caused by different soil expansion and contraction rates. The wall’s ability to hold up against this over a long period of time without major damage is directly related to the health of the mortar and health of the foundation footing. Yes, wall anchoring systems, piering and other geo-tech solutions will help the more severe cases, but for someone with no major foundation issues on a historic house, maintenance is the key.
Re-pointing and updating the mortar to a more modern mortar are keys to your field stone house’s foundation.
It will add needed strength, tensile and lateral, close gaps and in some cases help to give a cleaner finish. Closing the gaps between the stones helps to limit the amount of direct contact with soil moisture, limit bug infiltration, possibly limit radon levels, patch up major leak points, add support to the stone to stone joints, and gives you a good starting point to limit the amount of water that is coming into your basement. Further work can then be done to address those issues; however, by directly addressing the structural needs of the stone foundation you drastically reduce the need for chaotic repair in the future