How do I insulate below a fireplace?

Insulating a direct vent gas fireplace. - Fine Homebuilding

Finally got around to insulating my fireplace

Insulating around fireplace flue

Home Improvement Video: Insulate a basement faster, easier & safer - MyFixitUpLife

How important is the insulation AROUND the fireplace insert? (Especially FPX 33, Lopi Declaration)

Gas fireplace draft ?

The foil-faced insulation behind this fireplace provides an air barrier and thermal shield.

Sealing a Chimney Chase

Home Envelope: an energy guide to help you keep the outside out and the inside in

Three Ways to Insulate a Basement Wall - GreenBuildingAdvisor

Why is it important to insulate a chimney pipe? - Panadero

How do I insulate below a fireplace? AnandTech Forums: Technology, Hardware, Software, and Deals