There is one caveat though, it’s important to give freshly made concrete mantels some time (7 to 10 days) to “breathe out” any excess moisture they may have from the casting process, especially if they are installed close to high heat sources.
This is because if there is a lot of moisture in the mantel and it’s exposed to intense heat for an extended period it could spall along the edge that faces the heat since the water inside will try to turn into steam and find a way out of the piece.
Our mantels are made from a special CSA (Calcium SulfoAluminate) cement that is very heat resistant which reduces the chance of this happening, but it is always a possibility.
The installation was a little tricky and we did have to do some grinding on site but all in all the templating was close enough that it didn’t take more than an hour to fine tune it. Once it slid in, we caulked it into place to keep it from moving around. Overall, we think it came out really nice and so did she.