Many Memphis houses, especially older Midtown and Cooper-Young builds, have plaster bonded to wood lath that flexes when the frame moves even slightly. Loess soil beneath these homes softens fast after a heavy rain and stiffens again during dry spells, and that subtle rise-and-set motion telegraphs straight into the plaster. Strong storm fronts rolling up the Mississippi corridor can drop the air pressure suddenly, causing the walls to expand or contract just enough to open hairline cracks. Humid nights add another layer — plaster absorbs moisture differently than the wood behind it, so the two materials drift out of sync over time. We’ve walked into plenty of East Memphis homes where the plaster sounds hollow simply because the seasonal swelling popped it loose from the lath. Local suppliers like Home Depot on Poplar and Sutherlands carry lime-based repair compounds that behave better in our humidity than modern hard-setting mixes.