Try Fryewrap by Unifrax is extremely popular and good for insulating a fireplace pipe or even a chimney. Their products are fire and temperature proof. So they must be safe.
I've seen fiberglass in some DIY kits to insulate fireplace and chimney pipes. It saves money, but make sure you follow instructions and get an expert to check it after you're done.
Reply by
notanexpert (199):
Fibreglass??!!! Won't that stuff just melt and wreck the whole fireplace. i don;t think I'll be able to stand the smell they give out too! add a comment
Reply by
icyblue (236):
notanexpert - fiberglass is used mainly in cold pipes to prevent dripping, but I guess there must be some special grade of fiberglass that is very heat resistant too. But, I'd never try a DIY for hot pipes with fiberglass! add a comment