This is typically used on exterior stucco or on surfaces with many hairline cracks. Elastomerics are applied in thick coats and are able to span hairline cracks permanently. Rather than the cracks reopening on your stucco, the elastomeric coating stretches and keeps them sealed up. This prevents water from getting in and thus protects your home from any damage. Elastomeric coatings look a lot like paint and can be matched to your home’s color.