Welcome to Q&A for Home Maintenance Q&A section, where you can ask questions and get answers from me and other members of the community.

Spam, self-promotion, questions with abusive, inappropriate language, and irrelevant questions will be deleted.
All of the questions are moderated!


You'll be notified when your question is answered. Please reply with Feedback to share whether a solution worked or didn't work. Thank you!

Connect on Google+
Find on Google+ Local

Asbestos duct work under the slab

0 votes
Tom Fassnacht says:
April 22, 2011 at 3:42 pm

I’m a Realtor and during a home inspection today we came accross what the inspector thought was duct work for a forced hot air system that was made of asbestos.

Has anyone ever heard of this and what are problems with this system. The house was built in the 50's. Is there an easy way to solve this problem? The buyer is concerned.
asked in Asbestos by darekrudy (21,730 points)
Share this question on your favorite network.

1 Answer

0 votes

Hi Tom,
It depends… could you describe this duct work, location (under the floor / slab), suspended under the ceiling (a typical square air ducts) etc. ? There are a few types of based on asbestos ductwork materials and a few diffrent ways to deal with it, but it all depends on where it is and what is its condition. Describe in as much detail as possible. Thanks

answered by darekrudy (21,730 points)
Tom Fassnacht says:
April 22, 2011 at 4:25 pm

They are under the slab in one part of the house, it’s a split level design, the inspector says the put the pipe in the dirt and poured the concret slabe over it. To make slot for the vents they punched holes in the pipe and put vents down to the hole.The opening in pipe looks like the just punched thru’ with a hammer. The pipe is about 10 in round
There’s probably just a few of those vents in the floor and the rest of the house supplied with regular metal air ducts… Transite air duct pipes used to be manufactured with asbestos fibers to reinforce their structure. However, it is impossible to determine if they actually contain asbestos, what’s the percentage of it, or are those “good” or bad asbestos fibers without the material sample(s) laboratory testing. There are actually some “good” asbestos fibers that pose no threat to our health.

So that’s where I would start from, take a sample and have it tested. I’m in Illinois but local testing labs are expensive so my clients used asbestos-test.com – quick and cheap (all “what to do” instructions are on their website).

Assuming that those air ducts are contaminated with asbestos, the least expansive way to deal with it would be to disconnect them from the air distribution system, seal the floor openings with concrete or expanding foam, and open some additional ports to supply air to this particular idea.

The last part difficulty level depends on the HVAC system setup – they have to get a heating guy to look at it.

If those air ducts contain asbestos and they are in a bad shape (cracks, rough edges that could release airborne fibers), there’s a possibility of the entire HVAC system and home environment contamination… Again, start from the lab.
Tom Fassnacht says:
April 25, 2011 at 1:52 pm

Thank you you were a great help
...