FAQ
Q Will it work on duct board?
A Yes, it will work on duct board and we’ve used it here many times. We find that the duct board deteriorates over time and the black outer fabric liner breaks down and will cause fine black particles to be released into the air system. We coat this outer lining and it will encase the outer fabric and stop the release of particle debris. However, please note that due to the construction of duct board, it can only penetrate the outer layer; it does not make it to the metal structure since there is a fiberglass layer between the fabric top layer and the metal structure.
Q Will it work on flex systems?
A DuctArmor is not really intended for flex. There are certain circumstances where it will work, but our process is intended to be a full encapsulation of the interior of the ductwork. If there are large holes (over 1/2″-3/4″), our spray liner will just blow out into the open framing. If the flex is in an exposed attic, its usually best to replace it. There have been instances where we have found flex inside walls or soffits that only had minor holes. We have sprayed those and it worked just fine. The larger holes (from rodent intrusion, etc.) need to have some structure behind them for our material to adhere to.
Q What Are My Air Ducts Made Of?
A The majority of ductwork in the United States is made of rolled or galvanized steel, Transite (asbestos & cement), or sonotube.
Q What is Transite and Why Is It a Problem?
A Transite originated as the trade name that the Johns-Manville Corporation (originally in Manville, NJ) created for a line of asbestos-cement products. In time, it becomes something of a generic term for other companies’ similar asbestos-cement products. This material was made with cement and varying amounts (12-50%) asbestos fiber. From the 1950’s through the early 1980’s, many slab construction homes in New Jersey used Transite to fabricate in-floor HVAC ducts. Trenches were dug, the Transite ducts were placed in the ground, the slab was poured over the top, and then the furnace was connected and the vents put in place.
After 30 to 65 years of being subjected to the hot and cold blowing air through them, the Transite cement has experienced some level of deterioration. You might see this as a fine, white power-like substance in the ducts or around the floor vents.
Q What should I do if I have In-Ground, Transite Air Ducts?
A Two potential options include encapsulating your ductwork with Duct Armor or abandoning the in-floor ductwork altogether and rebuilding with overhead ductwork.
Disclaimer: Duct Armor is biased on this one! Encapsulating your in-floor air ducts is simple, takes just a few hours, and maintains the efficiencies of your original air distribution system.
But you do need to evaluate your options. Abandoning the transite ductwork would require some or all of the following over a period of days, weeks, or months: 1) Filling the existing ducts with cement; 2) Purchasing a new, updraft furnace; 3) Permits; 4) Deconstructing walls and ceilings in order to run the new ductwork through your house; 5) Putting your house back together and painting…everything. Beware the temptation to put the new supply vents and the return vents at the ceiling level: This could lead to huge energy bills because most of the conditioned air never reaches the floor level. And if you settle for the lower cost flexduct option, you may be impeding air flow, thus increasing energy costs. Flexduct can also introduce more carcinogens into your home because of its fiberglass insulation which is usually protected with just a thin plastic barrier. (fiberglass is a carcinogen)