How to Loosen Duct Seals

A variety of ducts snake through an average home, and some may be showing their age. When a duct develops large holes or comes partially loose, you may need to loosen the seal to repair or replace that section of ductwork. Most ducts commonly found in homes are made from flex duct or are of the older, round metal type. Either of these ducts is easy to loosen if you know what to look for below the shiny insulated wrap.

Utility knife
Screwdriver

Instructions

- 1
  Feel along the length of the duct for the nearest joint, which will be thicker than the rest of the duct. Use the utility knife to cut through any tape holding insulation on the duct. Do not cut through the duct itself. Peel the insulation back, exposing the joint.
- 2
  Look at the joint to determine the type of connection -- if the joint is coated in a white sticky substance, apply a little extra force when removing the screws, but do not panic: this is a sealant called mastic. Remove any sheet metal screws. Loosen the clamps that are secured with screws.
- 3
  Pull the joint apart with both hands. Avoid getting into the white, sticky mastic that coats the inside of many overlapping joints. Pull extra hard to loosen mastic; it will simply come apart with enough force. Look for additional screws if the duct doesn't feel like it will give.

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