Floor framing with a ledger

**benmecham** · 10-25-2005, 01:53 PM

I am drawing a house with a basement and 8" concrete stem walls. I want to keep the finish landscape grade as close to the first floor height as possible to simplify a concrete slab patio and also to avoid steps up from the garage into the house. I have been told to frame the floor with a ledger bolted onto the inside surface of the stem walls, which makes sense to me.
My question doesn't have to do with getting the program to work, I'm just trying to figure out what is standard to do in this situation... so the question is: when standard 2X6 exterior walls are framed on top of those stem walls, how is the extra 2 inches of concrete dealt with as far as the subfloor goes? (2X6 frame wall on top of 8" stem wall, with the floor joists and ledger on the inside of the concrete) I noticed on the video training that they dropped the ledger down enough to get the subflooring flush to the stem wall top -- is that the best way to do it, or do I want to run the joists flush with the stem wall top and then run the subfloor over those extra 2 inches?

Sorry for the lengthy explanation. I have to figure out how to post pictures... that would be a lot faster.

Thanks,
Ben Mecham

**RMorrison** · 10-25-2005, 04:47 PM

Ben,

Personally, I would consider using a 2x8 mudsill and top-flange hangers with no ledger. Then you could run the floor sheathing over the mudsill and avoid the problem area of the joint between the concrete and ledger, where shrinkage, etc. could be a problem. (Make sure to use Z-max hangers, though.)

**Jorge Araya** · 10-25-2005, 05:12 PM

"I want to keep the finish landscape grade as close to the first floor height as possible to simplify a concrete slab patio and also to avoid steps up from the garage into the house."

Aren't you supposed to have at least 4" to grade from any concrete surfaces?

**benmecham** · 10-25-2005, 05:28 PM

Yeah, 4 inches to grade -- which is why I don't want to have the joists sit on top of a mudsill and stem -- so I can have a 4" concrete slab by the front door, and only have to step up 4" into the house -- (4" of concrete plus 4" step-up to finish floor = 8" -- still less than a rim joist and mudsill would allow from grade... does that sound right?) Maybe I'm making this too complicated...

RMorrison,
Thanks for the idea with the 2X8's. I actually had someone else mention that to me as well, but instead of using top-flange hangers, just bring the ledger up flush to the top of the 2X8 and use standard hangers. (that's not a problem with code, is it?) If they both work, I'm not sure which one would be preferable. Would that present a problem with door openings? It would be nice to have the thresholds attach directly to the concrete instead of putting flashings over the subfloor...

**slatta** · 10-25-2005, 05:33 PM

is this what you are doing??? I think it is 6" to grade minimum...

**RMorrison** · 10-25-2005, 05:40 PM

Originally posted by benmecham
RMorrison,
Thanks for the idea with the 2X8's. I actually had someone else mention that to me as well, but instead of using top-flange hangers, just bring the ledger up flush to the top of the 2X8 and use standard hangers. (that's not a problem with code, is it?) If they both work, I'm not sure which one would be preferable. Would that present a problem with door openings? It would be nice to have the thresholds attach directly to the concrete instead of putting flashings over the subfloor...

If you raise the ledger, the bolts through the ledger probably will be going into the concrete pretty close (too close?) to the top edge of the concrete, especially if you use a staggered pattern. I don't know why you'd want to spend the extra labor and materials for the ledger just to avoid top flange hangers, but that's your call, of course.

**benmecham** · 10-25-2005, 05:41 PM

Wow, thanks for the pictures!
I think you may be right, 6" minimum...
Is there any way that you could post a larger version of those pictures -- that would be a huge help!
Is that a concrete slab on the right side of the basement wall? And subflooring that rests on top of the concrete? Sounds pretty darn close to what I'm attempting. Is there anything in the IRC that says subflooring can't be laid out like this?
Thanks again for your help

Ben

**slatta** · 10-25-2005, 05:51 PM

post your email, I'll send you the drawing file..you can edit from there

**benmecham** · 10-25-2005, 06:01 PM

Richard,
That's a good point about the bolts. I guess something in my head told me it was too easy with the hangers. I'm not a framer (if you can't tell), so most of this is a mystery to me.

Neal, that would be great if you could send that detail my way!
My email is: benmecham@icqmail.com

Thank you so much for all your help!

**kernsdan** · 10-25-2005, 06:47 PM

Pour a joist ledge into the foundation where the ends of the joists are. You dont need a joist ledge where the foundation wall is parallel to the joists. You can set your joist ledge depth so the plywood floor goes over the outside of the foundation on all sides. Then you can frame your walls on top. When you frame your walls with 2 x 6's it makes it easier for the electrician and hot water heat because the bottom plate will hang over the inside of the wall and you can drill your holes. Some people also call this an inverted brick ledge. Very easy to do. I do this alot on additions when the existing ground is high around the addition.

Sorry i just realized one of the drawings is exactly what I described. Remember though, you dont need the joist ledge on the walls that are parallel to the joists unless you need to get some plumbing in the wall. If needed you could just put a short ledge at that point. The less joist ledge you install the cheaper the price.

**Jorge Araya** · 10-25-2005, 08:50 PM

It all depends on what your city requires, the details look fine, but the idea of having
a narrow wall with a J bolt to it does not sound to be a code compliant thing, unless your
stem wall is really wide.
The pressure treated ledger is common in combination of top flange hangers mounting to
either a mudsill or to the ledger itself, you don't want to bolt too many items through the
side of the stem wall as this will decrease its strenght.
Someone mentioned about your subfloor, yes very important if it goes over the ftg. it must
trated as well and or be over the sill.
Electrical and plumbing comes into play, and from those details is going to be hard to get
utilities through. and already thinking that many bolts are penetrating the stem wall, uhh
not so real.
pockets may have to be allowed within the stem wall to get utilities thru.

**juststeve** · 10-25-2005, 08:55 PM

Ben-

If you use hangers you should definitely use top flange. Using face mount hangers on a 2x ledger prevents you from using the recommended 10d common nails to attach the hanger to the ledger. Simpson does make a 1-1/2" nail, but you get a fairly large load reduction factor if you use them in place of the recommended 10d commons.

**frwillia** · 10-26-2005, 03:37 AM

Originally posted by benmecham
I think you may be right, 6" minimum...

If the IRC applies, then this is the applicable paragraph:

"R404.1.6 Height above finished grade. Concrete and ma-
sonry foundationwalls shall extend above the finished grade
adjacent to the foundation at all points a minimum of 4 inch-
es (102 mm) where masonry veneer is used and a minimum
of 6 inches (152 mm) elsewhere."

I don't see any masonry veneer so the 6" would apply in this case.

If the IRC doesn't apply, then go find on line, or buy, a copy of the applicable code in your area and look it up. It is a real bad idea to "guess" about code requirements.

I love having the whole code on my HD. I bought the ICC's CD called "The Complete Collection" from the Contractor's Book Store on Canoga Ave. as one of my first purchases when I decided to design my own house - as I recall (I'm at an age where memory is not reliable) it was about $125.00.

Fitch

**Allen42acj** · 10-26-2005, 04:24 AM

You could always build a wall under the joist or shot a PT 2x under them into the cement(I would still use hangers then).
I dont know if they make over the top hangers for lumber ,they do for I-JOIST.
To post a pitchure=in CA-export-pitcure-save as a JPEG file,you might have to resize smaller(windows power toys= resizer)
Allen Colburn

**kernsdan** · 10-26-2005, 04:45 AM

We build walls like this all the time here in Colorado. No big deal. There is rebar supporting the higher outside part of the wall. If you think the design through it is real easy. As far as top mounted hangers, they produce a squeakier floor. We build alot over expansive soil here and put in structural wood floors for the basement floor with a crawl space underneath. My home is personally done this way. I framed it. I used top mounted hangers. We don't cut corners. I have squeaks! *****. I will never use top mounted hangers again even though it is easier.

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