[Mijotter]

So I removed the Panning for the returns and I found this going on. Is that hole there so the wall can breathe? Can I close it off? It connects to the return for the room upstairs and that is an outside wall.

 

[hammerlane]

I cant speak for the purpose of that hole but that notched joist is in no way suppose to be notched that much. If that is a 2x10, the maximun depth of a notch is 1.5 inches. See chart below.

 

[Duckweather]

Is that insulation in the hole we can see? How old is the house? It looks 40 ish. It may have been an old duct removed and insulated.

 

[hand drive]

certainly the work of someone who does not frame houses for a living. looks like a splice is in order...

 

[Maintenance 6]

Pretty much normal years ago I believe. I had one just like it and the same kind of notch on the opposite end of the adjacent joist. And the refrigerator sitting directly over both joists......:whistling2: Sistered new joists beside both.

 

[Mijotter]

yikes, so it's not supposed to be there. Is there anything that I can do to seal it off? The hole and the HUGE notch in the joist.

 

[Duckweather]

Can you take a mirror and look up the hole to see if anything is in it? Maybe a section of duct or insulation. sistering a joist to either side would help. Is that a wooden floor register to the right side of the notched joist?

 

[Maintenance 6]

I'm sure the hole through the plate and up into the wall was for air supply. Either heating or cooling. Most likely there was a vent fastened at the wall at one time. It was typical to use the joist cavity as a duct and line it or at least cover the bottom with sheet metal. The problem was that the joist cavities didn't always line up with the area where the vent was needed. So they'd cut the joist to allow the air to move to the next cavity. Looks like that's what you have. If you aren't using the joist as a duct anymore, then I'd sister the joist.

 

[carpdad]

It looks like ideal condition for condensation. I'd actually leave it as is and dry.

 

[Mijotter]

There is really old and brittle insulation in that hole. And yes to the right of it is a wooden vent for the return of the room upstairs but ends before the hole. And no i'm not going to keep using that anymore, just going to keep the normal return.

Sorry i'm a noob, what would be the best way to sister this small portion? How long should the sister be?

Should I close off that hole with wood or xps foam board?

 

[Mijotter]

Well mainly that hole. Want it sealed for good.

 

[Maintenance 6]

If you are going to discontinue using it, then I would stuff some insulation in the hole and then screw a piece of drywall over it as a fire stop. If it is going to remain active, then I would get a sheet metal boot to slide into it. As far as sistering the joist, you'll want to get a new piece in on top of the sill plate at the exterior wall. Make the sister as long as possible. Glue it to the original with some construction adhesive and then screw it fast with some structural screws. Some hefty C-clamps will help hold the two together until you get the screws run in.

 

[Mijotter]

Would there be a way to just bridge the joist either with a cross bridge or straight bridge?

 

[Maintenance 6]

You could add bridging, but it won't add any significant strength to the cut joist.

 

[hammerlane]

whoever installed water line for sprinkler system went a little overboard on the joist. I added some 2" angle bracket to span the gap.

 

[Mijotter]

Yikes, I guess. We're in the same boat lol.