Floor Joist Framing Notched at Top

[garbdesign]

I’m looking at purchasing a home built in the 1980s with a sunken family room. I was thinking of raising the sunken family floor by building up the subfloor to be level with the rest of the house. But I noticed these floor joists in the basement that bother me, and the added weight might cause the joists to fail. The joists appear to be 2x12 with the top end notched almost 8” down. It appears that the joists are only resting on 4” of support on the steel flange. My question:

1) Is this common for wood floor framing?
2) What’s the recommended repair?
3) What’s the best way to raise the sunken floor?

Thanks,
John

 

[slownsteady]

Is that directly below the sunken floor?

 

[nealtw]

Welcome to the site. You are right, that is not the normal way to do it. The fix would be remove the sheeting and put new floor joists on top of the beam to match the opposing joists. I would leave the old joist in place and sister the new ones to them.

 

[garbdesign]

Yes, it's directly under the sunken living rm. How did this pass a building code inspector?

 

[bud16415]

Neal’s method would work but it will be very disruptive to your home. I never understood the appeal of the sunken living room just a trip hazard as far as I can see.

My thoughts are you are correct they disturbed the joist right at a high stress point and I doubt anyone ran numbers confirming the strength. I see they braced below the ends against the flange of the beam and that looks like an afterthought .

The joists you have are 2x12 and should have adequate strength all but at the ends. You don’t show us how the other ends are hung so I’m assuming just the one end is in question. I would be looking at just strengthening the ends. If you could design a special metal hanger that would saddle under the joist where it is full width and carry the load up and above the eye beam or the nailer above the beam. You should be able to find a local weld shop to fabricate you some for not a great cost that you could install. Another method would be to sister on ends with glue and screws similar to the ends you have now for more strength. You could sandwich a layer of plywood in with the sister to get a lot of shear strength.
I will try and describe my third idea but depending on how good a job I do you might need a sketch. You could cut a piece of 2x12 like the tail end of a rafter that’s on a 45. It would be cut to closely fit the shape of the inside of your steel beam and then run up at that 45 and come to a flat top against your sub flooring it could be then glued and screwed to the joist. The change in grain direction and directing the load into the lower shelf of the eye beam would make a very strong connection.

Upstairs you could then rip your sleepers and lay some subfloor and level it all out.

 

[nealtw]

Bud; He did ask about raising the floor to the common height.

 

[bud16415]

I did understand that. My thoughts were ripping up his sub flooring might be quite the project in a beautifully finished home. Chances are the subfloor was glued and nailed. I would think his first plan was ok laying in sleepers and then new subflooring and finished flooring without a lot of mess. The OP had two concerns one being the original construction and secondly would the original construction carry the weight of the new work above.

If the sleepers were aligned over the joists could a connection be made between them and the joist below that would add some strength back in? I don’t know. I think I would toe screw them along their length at minimum.

Again I’m not a builder or a contractor, just a DIY guy like the OP. Then again a builder and a contractor put those joists in like that. I was just throwing out a few idea for consumption.

 

[beachguy005]

You also need to look at the span of, and weight being carried by, the 2x12 to decide if that notched end is acceptable.

 

[bud16415]

You also need to look at the span of, and weight being carried by, the 2x12 to decide if that notched end is acceptable.

Looks about 16'

 

[nealtw]

The proper way to do it would have been to fill the side of the beam and use hangers and the fix would be the same. Shoot blocks to thew beem and put blocks above the beem and install hangers and then the notches are no longer a concern. Most times a floor is made out of 2x10s I suspect an engineer said 2x12s to allow for the notches, Not sure I would want to add the extra weight of the raised floor on it, we don't know what the safety factor was.

 

[beachguy005]

Looks about 16'

You have a great eye. I couldn't tell what was under the flooring from that pic.

 

[bud16415]

Here is a vid on taking up a subfloor. All the walls are sitting on the subfloor and you would have to cut up close to the edge as shown in the vid. Then you may need a helper to get the new full length joists into the house and thread them down thru the opening and get them in place from above and below. Wires and pipes will have to be removed most likely as well.

[ame]https://www.youtube.com/watch?v=ZRm0HGXXT5M#t=508[/ame]

 

[nealtw]

Here is a vid on taking up a subfloor. All the walls are sitting on the subfloor and you would have to cut up close to the edge as shown in the vid. Then you may need a helper to get the new full length joists into the house and thread them down thru the opening and get them in place from above and below. Wires and pipes will have to be removed most likely as well.

https://www.youtube.com/watch?v=ZRm0HGXXT5M#t=508

Ceilinng is open below, amazing what can be done with a chunk of 2x4.

 

[garbdesign]

I was hoping to add a sub-floor running perpendicular to the existing joists to raise the sunken living room (as shown in sketch). But after noticing the inadequate notched joists, I might be ripping all existing joists and sub-floor. Only positive is that it give me additional 6” of head room in the basement by ripping out all joists and raising it to the correct .

“if you’re going to do something, DO IT RIGHT, the first time”

 

[nealtw]

Now let's talk about the other problem. The front wall is sitting on the floor.
So you will want to cut the old joist at the outside wall in the basement leaving that much floor to support the floor then inbetween the studs in the same outside wall above install solid blocking sitting on the bottom plate and the hang the new joists off of that mess.

 

[bud16415]

Just a curiosity question. The bulkhead that runs down between the rooms. How high will that be once you fill in the pit?

 

[slownsteady]

“if you’re going to do something, DO IT RIGHT, the first time”

By George, I think he's got it...and after only 3 posts! :banana::beer::banana:

 

[bud16415]

By George, I think he's got it...and after only 3 posts! :banana::beer::banana:

Well in his case he will be doing it right the second time.

 

[nealtw]

Just a minute, I have a monkey wrench.
If he fills all the spaces with solid blocking at the out side wall and the beam, he could just cut the floor in one peice and jack it up and install hangers. With 2x12s it is a very good floor.
Just a lot of cribbing and four bottle jacks

 

[bud16415]

Sounds like a lot a work to get 6" of head room in the basement.