In construction waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environments or underwater to specified depths. In buildings using earth sheltering, a potential problem is too much humidity, so waterproofing is critical. Water seepage can lead to mould growth, causing significant damage and air quality issues. Properly waterproofing foundation walls is required to prevent deterioration and seepage.