View Full Version : Suggestions for recommendations

Miriam Barton
06-03-2007, 06:47 PM
Have a situation where in the home inspection we discovered some rust in air/heat ducts that are located in the concrete floor slab of the house. The master bedroom especially has a small hole that has rusted through in the bottom of the air duct and further down the air duct you can make out more rust and possibly rust holes. This was the major problem, as the other only occurence of rust was in another bedroom and the only rust was where there were three nails located on the ducts further down.

Thinking of suggesting either concrete be poured in and all new duct work be done from the ceiling or just busting up the concrete in that master bedroom and replacing the duct work in that particular room. Here is my concern, from the photos I was able to take of further down the duct work in the master bedroom, there appeared there was a water line mark which was past the last rust that appeared to be holes. Supposedly they had high rain water close to flooding at some point last month and water might have gotten into the air ducts.

Should we recommend a restoration company or a HVAC company to be able to make these types of repair (running new air ducts or busting up the concrete and replacing the duct work)? Or is there other alternatives that we can suggest? There is a coating and lining service in town that we have used on a house we owned that showed some light rust from moisture, but since this hole at this house is on the bottom of the duct, I'm thinking there might be a foundation problem, though nothing we could visibly see. Might even be a leak from the master bathroom shower drain?

I'm thinking probably test for possible mold too?

Jim Luttrall
06-03-2007, 07:05 PM
Seal off the old system and replace with new attic or drop ceiling system.
It will be cheaper and better in the long run.

Bruce Breedlove
06-03-2007, 07:14 PM
This is one of the many drawbacks to slab homes. In my opinion the new ducts should be run in the attic. Installing new ducts in the slab is asking for trouble all over again. The ducts flooded once; why shouldn't they flood again?

Joe Nernberg
06-03-2007, 07:20 PM
Ditto to the above post.

Not as common in southern California. Ducts were "gurgling" while I was running the heating system on a rainy day last year. I don't spend a lot of time on the possible fix - just what's wrong.

Miriam Barton
06-03-2007, 09:17 PM
Thank you all for your input.

Any one know the average cost of filling in the old duct work in the floor and running new duct work through the attic? How pricey could it be?:confused:

I'm assuming any HVAC company could be contacted to have this done, correct?

So appreciate the help.

Richard Rushing
06-03-2007, 09:36 PM

Yes.... an HVAC contractor.

Price? Just not enough information to be able to guess. How many levels, How many units, is the attic easily accessible, are your units already appropriately sized or are they under or over-sized (tonned), what about return air??

There are just too many varriables to even put a W.A.G. (wild arse guess)to the cost.


Miriam Barton
06-03-2007, 10:00 PM
Hi Rich:

I'm talking about a 2400 square foot one level home, The attic is easliy accessible, using the same heat/air unit as they are the correct size and the return air registers are both in the attic already and no problem with them.

Just a matter of filling in the old duct work that is originally in the concrete floor of the house (that has rust and water damage) and usining the existing air/heat unit but run new duct work and vents through the attic instead.

Does that help a little?


Scott Patterson
06-04-2007, 05:42 AM
I would hesitate to get pricing from a group of home inspectors. I think you will find a vast difference in pricing around the country. If I recall a ballpark insurance figure is around $7 to $9 per lineal foot of duct.
Call up a local HVAC contractor and they should be able to give you a range in price for your area.

Richard Rushing
06-04-2007, 05:58 AM

I just looked up the pricing for your area (Ok city-- is what I used) and you should count on between $225 and $250 per room/run (ex; 10x+250=betweem $2250-$2500+ service chg and any applicable taxes)

I use Xactimate 24 so my pricing is based on insurance standards and costing of specific areas of the country not general pricing.

Hope this helps...


Miriam Barton
06-04-2007, 07:07 AM
Thank you so much Rich. That does help a lot, I wanted to know about an average for budgeting purposes. Not even knowing off hand was kind of scary thinking it might run up to $10,000. But since it appears it might run lower than $5,000 that eases the situation.

Jim Robinson
06-04-2007, 02:32 PM
Just to put another thought into your head, check into running PEX for hot water baseboard. You're essentially installing a new system anyhow. However, I guess if you need AC, forced air is probably the way to go. Not much AC in my area, but there probably would be in OK.

Bob Harper
06-04-2007, 05:25 PM
If you discontinue those old ducts, they will still present a health hazard as they breed all sorts of goobers and goblins. Probably need to bust them out and backfill appropriately.

While I hate the thought of ducts outside the thermal envelope of the home, this is one case it may be better as long as they are installed properly and sealed.