Yeah, you are correct no damper control in the vent shown. Ill take care of it. We have one that is full with stuff pretty much the same. Mom said she is going to sell some of it and find a new place for the stuff she wants. Still have to get some quotes on the exterior metal chimney. Read they work if set up properly. Ill have a professional do that and the fitting of the chimney. Ill build the hearth I tiled the bathroom floor and did a nice job. Any specific grouting or stone/tiles that need to be used due to heat? I tried to search it on the web here but only found people building it and not discussing if a special material was used.The returns can usually be told from the supplies by the vanes. Supply vents usually have a damper with a little handle that allows you to adjust the flow. Return grilles are unrestricted. Sounds like you have it figured out. Now may be a good time to look for a freestanding china cabinet .
Anyone build thier own hearth? Remove carpet, use concrete/rock board mortar and grout away?