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 ...

Q Am I right that when sections of plaster break away from the lath, an accepted repair technique is to roughly fill in those gaps with drywall and then drywall over the whole wall or ceiling? — M.H., ...