Adding Duct work, can I run up walls and through top plate?

Question

I'm adding duct work in my house, and I've been told that I can just run the ducts up the walls and into the bedrooms on the second floor. The walls are load bearing and I was told I could just cut through the top plate and brace it.

Is this possible? If so how do I brace a top plate? Should I use oval ducts in walls?

Answer 1

I have to agree with Don about the header, but wanna add my own two cents too.

Consider the diameter/ measurements of usual AC/Heat ducting...then consider the thickness inside a wall...approx. 3 5/8 inches.

Every house I've ever owned with AC/Heat pump had the Fan unit outside and the condenser/coil unit in a garage or some such; DUCTING to an attic or crawl space; then registering from the ceiling, in the various rooms; with returns in the ceiling elsewhere, as well.

Certainly there are variations I assume; IE: floor registers and a closet return system such as often is found in a mobile home;;;But you don't detail the TYPE of system.

Without knowing at all the TONNAGE involved I suspect you should; and the appropriate sizes of the VARIOUS ducts needed. Without at all knowing the sq. ft. of your house I'd probably suggest no less than a 2 or 3 TON unit. I owned a house at 2000 sq. ft. and upgraded to a 3 tone for a singel story. Standard is 1 ton per 750 sq. ft. plus or minus.

Steven Wolf

Answer 2

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RE:
Adding Duct work, can I run up walls and through top plate?
I'm adding duct work in my house, and I've been told that I can just run the ducts up the walls and into the bedrooms on the second floor. The walls are load bearing and I was told I could just cut through the top plate and brace it.

Is this possible? If so how do I brace a top plate?...

Answer 3

There is a 2 piece square ducting you can get at some home stores, it is approx 13 x 3 when put together. It fits inside the wall cavity of 16 inch on center 2 x 4 walls, and you can adapt it to regular round flex ducting easily once through the ceiling. I would not cut the sill plate on my house, just build a fur down or box that bypasses the area. Build out a small section of wall and finish it out like the rest of the room, tape float texture, trim molding etc. It will look better and not jeopardize your structure.

Answer 4

You can use a duct to go up the wall, but do not cut the top plates, a furr down to cover the duct as you come out at the top of the wall and feed through the second story floor.

Answer 5

Wow....If an HVAC guy ever cut the top plate in the frame of my house, it would be the last thing he ever cut. I would not recommend this. The top plate needs to run continuously from corner to corner to function. That's why the joints are always staggered by two or more studs. A top plate works in tension, to hold the two corners together. I don't pretend to know everything, perhaps there is an approved bracing method, but I've done my share of framing and I would try to find another way.

Answer 6

if this is a reno and going up inside walls and that they are not load bearing,yes you can if you strap the cuts with a metal straping, I would not go up outside walls at all,if you can go up a closet or a corner you could box it in. have fun, ps seal the duct as best you can tape or duct sealer,its in a can

Answer 7

How To Run Ductwork

Answer 8

you have to use plate strap, typically it's a 36" long by 2" wide strap with lots of nail holes, one per side, you then use TICO nails to nail the cut through section like a mend, but since it's a load bearing if this was California you have to shear panel one side for added strength