Yes, you can put lime under your house in certain situations. Lime powder can be used in a crawl space to absorb strong odors and suppress humidity. However, it is important to use the correct type of lime, such as powdered lime found at home stores or garden centers, and avoid using calcium hypochlorite, which can release harmful gases. Lime should be spread on top of the existing vapor barrier, but it should be removed and replaced with a new vapor barrier once the odors have dissipated.