A pebble from the lawnmower that flies against a window. A drink set down too heavily on your glass-topped coffee table. A favorite vase tipped over by your curious cat: These are the types of ...

There are two kinds of cracks in old lath and plaster walls. Both can be repaired, but one is a much more serious problem. By Ronda Kaysen Q: Our Gramercy co-op was built in 1929. The thick plaster ...