Mending wall
Most people expect wood to decay, they assume stone will last forever. Stone buildings are subject to the same detrimental effects of weather and other environmental factors that can damage wood and other siding materials. Shorter, more exposed, stone boundary walls need regular maintenance. I learned that from Robert Frost, when I was in school. Remember Mending Wall?
Stephen Roberts , from Housemaster Home Inspections, explained it to me less poetically:
Water is almost always the source of the problem. Moderate exposure to rainwater is inevitable and, to some extent, beneficial as it helps clean exterior surfaces. But damage occurs with cycles of heavy saturation and drying. These cycles may be caused by seasonal weather factors, leaking gutters, ineffective cornices, blocked drains or clinging vegetation.
The most common causes of stone deterioration include:
• The freeze/thaw cycle. Stones are porous. Water is absorbed, then freezes and expands.
• Salt crystallization. Soluble salts are carried with water into the pore network. The crystals expand, too. A telltale sign of a potential problem in stone is the formation of efflorescence (salt deposits) on the surface.
• Acidic action. Acid deposits dissolve stone.
• Vegetation. Moss, vines and even thick shrubbery around a stone foundation trap moisture in stone and prevent evaporation. The greatest damage is often caused by roots; they grow in little cracks, making them bigger.
• Structural movement. In cases of severe settling or upheaval, sound stones will crack at weak points, such as lintels and sills of doors and windows.
Stone veneers, such as the currently popular manufactured stone products, are subject to many of the same problems as real stone. Manufactured stone is a synthetic composite made with certain qualities designed to even improve on real stone, but can have other problems. It also matters that your manufactured stone is installed properly.
Stone is a less-common siding in Eastern Massachusetts. Do you have it? Do you like it? Have you mended your wall?
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To add to the above, brownstone is a particular risk for spalling, as its so porous. The wet-freeze cycles of massachusetts are quite hard on it. Take a look around the south end and back bay and you'll see the repairs.
Veneer construction also raises its own issues.
But all in, stone and brick do require maintenance no doubt. But it is literally orders of magnitude less than that of wood - repointing a brick house once a hundred years can be fine. Wood treated the same would be in rough shape.