Help - Duct work against floor joists?

[dewitt492]

I am remodeling my basement and have a ceiling clearance issue. Local codes require no less than 7'.. I can't meet the 7' mark but the local authorities will give me a variance if I do the following:

Except for the first 7 feet of the supply run, raise the supply run so it is directly up against the floor joists. This would raise the ductwork 1/2" to 1". My question is has anyone heard of putting something such as tarpaper between the top of the duct work and the floor joists? I believe the purpose of this is to avoid any rattling noise that might be caused duct runs during expansion and contraction.

The first 7 feet of the supply run has to be replaced with custom ductwork done to make it wider and 8" deep. There is room to do this. The 7 feet comes from code in this area requiring it to avoid drying out the floor joists and making them more combustable (sp?).

[Toolpusher]

Sounds like another group of people with too much idle time on their hands.

It seems as though they will put changes or new codes in just jusitfy them being on a planning brd.
No-matter how stupid the code is.

I go into tons of basements that in no way could ever meet those standards, But by them doing this, it allows them new money for apllying for a Variance.

I've not heard of the tarpaper deal,

[fat eddy]

I actually ran into this problem before, but it had to do with 7' clearance only at the stairwell into the basement and they let the rest go on a variance. ( somethimg to ask about )

[pipedope]

give the inspector a c note and run the ducts as you wish

[amickracing]

One thing to also consider, if you put the duct tight to the joists you could possibly get a "bong" sound as you walk over that part of the floor, from the joists moving a bit.

Good luck

[duc dowg]

all for a half inch?

[mo-flo]

put cork pads under furn.,break mark duct,use duct connector with canvas in middle....maybe a little flex on branch runs.....do eveything you can to isolate vibration from furnace to ductwork....where it is not as ridgid.IMO