No, your basement dehumidifier doesn’t need to be on 24/7. While it’s an excellent tool for tackling damp, musty air, especially in humid seasons, leaving it running nonstop can backfire. Over-drying the space can mess with your sinuses, warp wood, and even crack certain materials. Instead, only use your humidifier when moisture levels rise above 50%, and then give it a break when the humidity levels drop.

A leak under your foundation from a water supply line or sewage line is likely to lead to water pooling on certain areas of your property during rainfall, abnormally fast-growing or green grass in certain sections of your lawn, and differential settlement of your foundation, which can result in large foundation cracks, windows and doors failing to operate properly, a wavy or sloping roofline, or damages or irregularities in your interior walls, including cracks and bulging. If it’s a plumbing line embedded in your slab, you’ll also likely notice above-average water bills.

External pressure on the basement wall can cause it to bow inward. Soil, heavy with water saturation, is commonly the main culprit. The soil exerts immense pressure on the wall, causing it to fail, at least partially. This is known as hydrostatic pressure—these situations can occur after rainfall or simply due to regular groundwater presence and may be temporary or more permanent.  

Crawl spaces are prone to issues caused by excess humidity and improper ventilation, but that doesn’t mean you should avoid buying a house with a crawl space. A home that is encapsulated and well-maintained shouldn’t have any more issues than a slab or basement home.