We are having a fireplace added to a covered patio project. This is our last step of a very difficult project. We have had to watch and ask for corrections (which have been made) along the way. The fireplace is having many issues, one being they want to put the whole manufactured stone up in less than a half day and this gap. I am working on the first part with requesting it be done properly with the backing of much support. I haven't been able to figure a fix here and they are looking into this one. I think they are asking the same stone subcontractors though who don't seem to be doing a great job. Also, their initial thought was just to extend the metal lathe and apply stone over it. That would mean 2-3/4 inches, almost 3 inches on each side that have cedar siding, cedar trim and a void that I can see my back yard through and no backerboard, wrb before the mortart is added. Yikes! I am a novice, but that sounds like trouble. So how can we fix this appropriately so the stone extends to the edge?