how to fix holes in flexible heating ducts under house?

aluminium tape will patch the holes

but flex duct is for lazy people

install the real thing

and if they run in a non-heated area make sure they are well insulated (save you're money)

Flexible Heating Ducts

use what ever size round pipe the duct comes in as a coupler/splice and splice the duct back together. cut about a 8" piece of pipe and pull the inner part over the round pipe half way and put 2 rounds of tape over it. pull the inner part form the other side over the taped off part and go over that side twice with tape and put 6 or 8 screws in it to hold it......pull the fiberglass up and over lap it and do the out side skin the same way was you did the inner skin.

Without knowing the material they are made from, I might assume they are an aluminum /// or vinyl alumi num covered flex tube. Certainly Duct tape,,,as I have stated here, often. is one choice. Another is the shiny, chrome tape made specifically for duct work.

Rev. Steven

the answer is obviously duct tape..that is what it is for