When it comes to repairing sheet metal ducts, there are a few key points to keep in mind. Before starting any repairs, it is essential to ensure that the hangers you plan to use are approved in the local area where the building is located. Mechanical engineers should specify the approved suspension methods in the specifications, if provided. The cost of repairs will depend on the extent of the damage, the difficulty of accessing them, the price of the individual components (depending on the material you choose) and the labor required if you need the repair to be carried out by a professional.
It is important for homeowners to understand the difference in costs between repairing and replacing air ducts to decide what's the best course of action for them. Air ducts are usually made of galvanized sheet metal, such as square ducts with button closure or round ducts with snap closure. If dirt and moisture are allowed to enter the duct system, there may be no significant difference in the rate or degree of microbial growth in internally lined or bare sheet metal ducts. These are usually the lowest-cost pipelines in a home, and labor often accounts for most of the repair bill. This is particularly true if you realize that you're going to have to make cuts in the walls, ceiling, or floor to replace or repair air ducts.
The disadvantages of these types of ducts come from their thin layer and can include cracks, holes, and air leaks. In case of a minor duct repair, such as touching an old duct or replacing an existing duct, you may be able to do it yourself. Air ducts can easily be repaired or replaced by a professional, but it's also possible for a homeowner to do this with the right tools and an extra set of hands. Most organizations that deal with duct cleaning, including the EPA, NADCA, NAIMA, and SMACNA (the National Association of Metal Plate Contractors and Air Conditioning), do not currently recommend the routine use of sealants to encapsulate contaminants in any type of duct. Repairing sheet metal ducts requires careful consideration and planning. It is important to understand what needs to be done and how much it will cost before starting any repairs.
Homeowners should also be aware of the difference between repairing and replacing air ducts so they can make an informed decision about what is best for them.