Forced air ducting in concrete slab deteriorating

February 11th 2011
Forced air ducting in concrete slab deteriorating

This question came up recently on the Home Discovery Radio program, it's a commonly asked question in the early Winter when people turn on their furnaces for the first time of the year.

Q: We have a 30 year old home, built on a slab, with the furnace ductwork embedded in the concrete.  Recently we have noticed "sandstorms" rising up from some of the floor vents when the covers are removed and the furnace fan is blowing on high speed.  Apparently this is a common occurrence in this type of home, where the ductwork begins to rot and the foundation sand has become exposed. We have heard various stories from neighbours about certain "fixes", including robotic cameras, sprays and flexible vinyl sleeves inserted into the damaged duct. However, we have yet to find any professional who has knowledge of such things, and have been told the only solution would be to re-duct the whole house from the attic.  Any suggestions?

A: This has been an ever-growing problem with homes that are built on slabs with the forced air ducting in the slab. The salt in the sand fill under the concrete is the culprit, as it will deteriorate the ducting.

We have seen this problem before and rectified it by using the existing ducts to distribute wiring that will accommodate electrical convection type heating units to each room. This is easily accomplished as your electrical panel is usually in close proximity to your furnace location. The heating units are called Convectair. This is a very efficient system and is available through a Shell Busey Home Service Referral Network member.

Please call Shell Busey's Home Service Referral office at 604 542 2236 and we will have the proper service person come to your home for a quotation.