Below Grade Air Ducting

The Source For Air Duct Repairing of Underground Air Ducts

Furnace Air Ducts Installed Underground

High end homes and home located in areas where height requirements prohibit attic have air ducts underground. Mariposa, Laguna Beach, Corona Del Mar and Palos Verdes are common areas where air ducts have been installed underground. You don’t need to spend a $100,000 in remodeling to fix these underground air ducts. Your just need to give us a call and let us help you into a cleaner indoor air environment.

The Problem With Underground Air Ducts

Most air ducts installed under the concrete foundation of a home are just plain galvanized steel air ducts surrounded with 2 inches of concrete. Since concrete is not water tight the galvanized steel ducts are immersion in moisture nearly year round. This means that, despite the zinc coating on the steel air ducts, they will rust through. This leads to sand, dirt and debris, mold, mildew and bugs getting into the home environment.

Moisture Damage to Your Home

Look at the upper picture of underground air ducts. That is called a plenum and often it is the worst part of the picture. This came from a home in Corona Del Mar. See the water stains from standing stagnant water on the sides of the sheet metal. The home required a dehumidifier every time it rained. This situation put the very real danger of mold and mildew growth through the home, in the bathrooms, in the closets, in the walls and in the cupboards. The underground ducting was broken and water was leaking into the home.

We Have A Solution

Hammering up the concrete in the home and replacing the ducts is a solution, but a very expensive one. The floors would need to be replaced, the walls would have to be patched and the homeowners would have to moved out for a few weeks. That isn’t a very practical repair for broken underground concrete air ducts.

Here is The Solution

We rebuild the plenum with polyester resin and water tight cloth. This is much like building a boat or a surfboard. Very water tight. The ducting is another challenge altogether. It first must be cleaned as well as possible with vacuums, air brushes and physical brushes. Which method is chosen depends upon the condition of the underground air ducting. The ducting is then patched where is collapsed with an expandable bladder and a resin soaked felt liner. The rest of the ducting is coated in a heavy layer of epoxy resins to form a new inner layer of ducting within the outer layer.

Finish and Trim

We put the furnace back in, perhaps a new furnace, and let you know your options for real indoor air quality cleanliness. After we are done you will not believe the difference. Asthma and allergy problems caused by the airborne debris go away leaving your home a healthy place to live in.