How to temporarily remove section of duct?

As part of some hardwood floor repair, I need access to the exposed sub-floor in the basement. One section I need to get at has some ducts running through it. I just want to pop these sections off while I do the work. This sounds easy, but I have never worked with ducts before, and I am unfamiliar with how they are joined. I don't want to go and pull it off, only to find out that I can't put it back.

You can see pictures here:
http://community.webshots.com/album/549602552ZhGvuL

What is the best way to pull these down without needing a blowtorch to get them back up?

Thanks!

 

This is an easy one to answer.

The ducts are connected with S and Drive. The S is on the top and bottom. S is just a piece of metal, usually about 3/4" shorter than the width of the duct. If you take it off and look at it from the end, it's shaped exactly like an S. The two pieces of duct slip into this S on the top and bottom.

Now the sides are the part that actually holds it all together. This is the Drive. Each piece of duct has a backwards facing hook thats formed or bent onto it. When you put 2 pieces of duct together, the drives butt right up against each other. Then you take a piece of metal called a Drive and it slips right over the drives on the 2 pieces of duct.

It's a lot simpler than it sounds.

The duct is being held up with some hangers and screws, it looks like.

Just pull the drives off the seams/joints with a pair of vise-grips. Drives are usually bent over the top and bottom and smashed flat with a hammer. Just pry the end up with a flat screwdriver and then grab the drive with a pair of vise-grips. Start hitting the vise-grips with a hammer to pull the drives off the duct.

You can usually buy Drive at the Home Depot or any other big box store. If not, then go down to any local heating supply warehouse and go in and ask to buy 8 feet or 10 feet of drive. It's easy to cut with tin snips. When you are ready to connect the ducts up again, cut your drive about 2" longer than the side of the duct. Hammer it on the drives on the duct and then bend over 1" on the top and bottom. Hammer it flat on the top and bottom.

Consider the drive metal that you are pulling off the ducts as expendable. It's cheap, and not worth trying to salvage. Buy some new drive.

The drive flanges on the duct are probably going to get bent up a bit from removing the slip on drives with a hammer and vise-grips. No problem. Just take a pair of pliers or needle-nose and try and form them back to original shape as best you can before putting the new slip drives back on. Obviously, sheet metal professionals have specialized tools for folding drives and working on this stuff, but it's nothing you can't do on your own. It's only going to be 1 or 2 joints of duct and an offset elbow. Not nearly as hard as it looks.

We always joke that you can train a monkey to do sheetmetal work-------as long as you have plenty of ripe banannas.

I can say that, because I've been a tinner for 12yrs.

 

what about the takeoffs coming off of the top of the duct?

 

I don't see any take-offs in the pics he posted.

That looks like old duct to me. Also looks like 47" sections. Piece of cake to drop that stuff down out of your way and do your work. Then slap it back up with a couple new drives and hangers.

If there are top take-offs, you just work them from the top. Get the register off and get down in there. Pull the dove-tails out or pull a few screws. Reinstall in reverse order.

Simple for a good tinner. Not all that hard for your average homeowner either. All he needs is some encouragement and someone to tell him how to do it.

Sheetmetal ain't 1/2 as hard as most pople make it out to be.