Cap Plate Question

[idoc4u]

From the image you can see that some of my duct work runs parallel to my joists. I would like to run an untreated 2 x 4 cap plate for a wall perpendicular to the joists and under the duct work. I would attach the studs to the cap plate that would be nailed into the joists.

My question; is there any problem with nailing a cap plate into the joists directly under the duct? I will obviously be driving nails into the joist through the sheet metal and the 2 x 4 cap plate will be making contact with the duct, but the nails will be into the joist and not just sticking into the duct.

Thanks for opinions.

[Ian Gills]

I would screw it and not nail it and even then you might still get some problems with noise.

And I would avoid going through the metal. You can get through the wood there.

As the ducts heat up and cool down with your heating system they can sometimes make annoying sounds (especially at night) as they expand and contract around things they touch.

Screws can sometimes help.

[idoc4u]

Thanks for the reply, Ian.

In the case of the wall I intend to build, the top plate will actually end at the joist in the middle of the duct that you see.

Therefore, the plate will run across the bottom of the duct as your looking at it in the photo from left to right and end at the middle joist where the duct is nailed in the middle.

Screwing it in is a great idea, I just wasn't sure if I could run the plate across the bottom without creating too many creaks in the night.

Thanks again.

[iminaquagmire]

You could always use a piece of sill sealer in between the duct and the top plate. It would uncouple the two. Then screw it in place. Screws are easier overhead anyway.

[hj]

That is a return duct and there will be NO noise from it. Neither is there any problem with crossing under it or nailing through the metal "flanges'. In other words ignore it, forget it is there, and just do what you originally intended to.

[idoc4u]

Thanks for your input, guys!