Tying into existing ductwork

Hello guys, some assistance please.

In a previous thread I stated that I was redoing my kitchen. One of the things I am doing, is relocating my heat duct in the room. It was originally one of the older grate style in wall/floor grate systems, but I am replacing it with newer duct work. I was able to go to my local home improvement center and get this stuff called wallduct. It's basically two L shaped pieces that snap together to make a rectangle 'duct', that fits inside the wall cavity. From there, I got a stack head that attaches to the top of it, and at the bottom, I have a flange that goes from 8" round pipe into a rectangled piece that is supposed to fit into the wallduct. (stack end tube). The problem is, the diameter of all the openings is the same size, and I can't piece them together. I can tell by the edges they are supposed to snap together somehow, but I can't seem to find out how to fit them together.

There are these things I got, I think they called them cleats, that slide over one end of the wallduct, but the problem is, the ones they gave me were called like s'cleats or something, and it still doesn't work because the diameter of the two vent pieces is the same, so one cant fit inside the other one.. am I just using the wrong cleats or whatever they are called, or is there no way to fit these pieces together?

I will try my best to get you pictures of the parts that I got, based on the pictures below:

2 of these:

http://www.homedepot.com/p/Master-F...Rectangular-Stack-Duct-RD3-25X10X36/100139237

One of these:

http://www.homedepot.com/p/Speedi-P...-in-Wall-Stack-End-Boot-SM-W3106-EB/202907248

One of these:

http://www.homedepot.com/p/Master-Flow-10-in-x-6-in-Rectangular-Stack-Head-SH10X6/100192231

Two of these (Except 10"):
http://www.homedepot.com/p/Speedi-P...-ESS-Cleat-Duct-Connector-AC-ESS-60/202907030

. I was able to get the end boot and the duct to fit together, but I can't get the stack head and the duct to fit together as they are the same size.. Is there something that I am supposed to put between them to make them fit together? The ones they gave me have a tab on them that sticks out at a 90 degree angle from the cleat itself, so it's possible they gave me the wrong ones, is that the solution, or am I doing something wrong?

ALSO, do they make 7" round pipe? I used a tape measure to measure the width of the existing pipe, and it came out to 8", but when I got an 8" to 6" reducer, the 8" end was WAY bigger than the existing pipe. The 6" one was more accurate but I know the pipe is bigger than 6"

Many areas have different terminology for parts ....

What your calling cleats I call slips. The pic you posted is an 's' slip . The slip with a 90 degree bend on the end is a bar slip. It's usually used on ductwork wider than 24" to give it strength.

To make the connection I would use s slips , when you put them on the first peice , you can flip them so the receiving side of the slip is in or out . So say you put receiving end in front in , on back out , on right in , on left out. By doing this your making the same size to the receiving duct.
If you have bar slips , you cant reverse them like that because the bar reversed , would be in the air flow. In this case the receiving size grows . Notch the receiving duct so you can bend the ends out and make that end grow enough to fit into the slips.

7" pipe is available but not typical. A home depot may not carry it or a reducer to that size.

I'm sure none of this makes sence. It's hard to teach from words. I have a kid on my job with months experience and has these basic questions still.

If all else fails , what ever you do , screw your connections , and get duct sealer and slop it on. Not pretty but just as effective.

What your working with is rectangular wall stack. If you ever do a project like this again , look for oval wall stack. Much easier to work with for a newbie .

Thank you for the information. As I read this post last night, I was walking into the local home improvement store to look for the correct cleats. As I went down the aisle i found the oval ducting and picked that up instead. It seems to work a lot better, and yes, the original pipe was 7", and they happened to sell a 7" to 6" reducer, I just had to cut the pipe a little bit to make it short enough for the new adapter to fit on it.

I am not back to putting on the drywall and getting the house back into shape.

Thank you for the quick reply, and information.

when you run into different types of duct joinery. overcome/adapt use a crimp tool to change the size of the duct



something that is missed when calculating your duct size is the insulation,

your duct needs to be insulated or it will sweat,

if you figured you duct inside a wall, you need to add 2'' to the debth of the wall.

1'' of insulation on each side of the duct.