Mantels give your fireplace an extra level of aesthetic detail that can really tie everything together in terms of design. They also serve to protect the fireplace opening from cracking over time due to heat fluctuations which is particularly helpful if you live somewhere with colder seasons (i.e snow or ice). Mantles can be mounted on either drywall or brick depending on what material your home was originally built with but it’s important to note they should always be fitted before drywalling/masonry work has been done around them so all surfaces line up correctly while maintaining structural integrity against shifting weight.