Author Topic: letting in ledgers for floor joist.  (Read 63144 times)

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Offline PEG688

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letting in ledgers for floor joist.
« on: April 10, 2006, 06:08:42 PM »
  A while back some one asked this question. Here's how I'm doing it on the job we're framing right now .


   Racked the studs / trimmers / and upper cripple studs interior side up on the deck using the gable end wall as the upper stop , and a floor sheathing seam as a 90° guide . Nailed a block along the seam to hold the stud etc true. And used two pipe clamps to pull the works together.

   I laid out the ledger location as per plan.

   I used a cut off piece of plywood as a saw guide , tacking it on 1 1/2 " away from the desired cut line , and ran the upper kerf. Set the saw just a fuzz shallow , trying for 1/ 16".

  

  Then moved the guide to the lower kerf ,

  

  After the kerfs where cut I used my hammer to knock the waste out ,

  

   After sweeping the area / studs etc off , I used  a plunge router with a  1/2 " shank , top guide bearing , pattern bit.

  

  I added the 3/8 " plywood base to span the area of the let in , by taking out most of the waste the router doesn't work as hard , and in the long run that saves time . Instead of hogging all that wood with the router .

  
 

   Makes a nice clean cut,  :)

  


   The south wall I did last week without the router , same process only bottom of the let in was cleaned up with a chisel, and I set the skil saw a fuzz deep , 1/16" so the ledger would be just a little bit set back from the stud faces.

    

   The wide one  :)

  

    All in all the router was cleaner but I'm not sure faster , which means $$$ to a builder. Both ways work  :)

  You might notice these walls are made up of 2x6 spruce , 4x6 fir and 4x6 LSL. 24" OC , the joist will be nailed , one joist each side for  a "look" and nailed to the 4x s with 4 ea. 16d nails , staggered, per joist.

   Couple of long shots ,
  
  

    

    Good luck , PEG
« Last Edit: April 10, 2006, 06:49:33 PM by peg_688 »
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Offline John Raabe

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Re:  letting in ledgers for floor joist.
« Reply #1 on: April 10, 2006, 06:33:34 PM »
Great How-To PEG.

Thanks,  :)
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Offline glenn kangiser

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Re:  letting in ledgers for floor joist.
« Reply #2 on: April 10, 2006, 06:58:13 PM »
Good show-n-tell PEG :)
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Offline John_M

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Re:  letting in ledgers for floor joist.
« Reply #3 on: April 11, 2006, 02:58:52 AM »
That was me originally asking the question!  Thanks!!  That helps me out!!
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Offline PEG688

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Re:  letting in ledgers for floor joist.
« Reply #4 on: April 11, 2006, 04:30:07 AM »
[size=12] Your welcome  :) [/size]
When in doubt , build it stout with something you know about .

Offline Amanda_931

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Re:  letting in ledgers for floor joist.
« Reply #5 on: April 11, 2006, 06:12:28 AM »
Seems like I used not to bother cleaning it up much if at all after knocking the sawed space out.  If I'd done a good job sawing it still worked (and besides the only chisel I had at the time was a 1/2 inch one), but, good grief that router method makes it look sooooo nice.  And it's sturdier than a half-assed smoothed space to nail the ledger into.

And I'd have come close to killing for a port-a-potti on a fair number of jobs.  :)
« Last Edit: April 11, 2006, 06:15:10 AM by Amanda_931 »

Offline Jared Drake

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Re:  letting in ledgers for floor joist.
« Reply #6 on: April 11, 2006, 08:00:03 AM »
Are the walls framed 24"OC? I was told on this forum that it would cause wavy walls inside and out.
Jared

Offline PEG688

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Re:  letting in ledgers for floor joist.
« Reply #7 on: April 11, 2006, 03:28:02 PM »
Quote
Are the walls framed 24"OC? I was told on this forum that it would cause wavy walls inside and out.
Jared


  [size=12]IMO ,when we're done the walls will look wavy.  
[highlight]
  I'm just the lead carpenter, I did not design this house, I only buildum , to the specs. provided ;)[/highlight]

   Those issue's are beyond my control.   I would not build my house or cabin on 24" centers. But that is just my opinion.  24" OC meets required code.

  The other thing with this place is all the 4 x6 material , all driven by the project [highlight]engineer. ::)[/highlight]  

  PEG    
[/size]
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manhattan42

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Re:  letting in ledgers for floor joist.
« Reply #8 on: April 13, 2006, 05:42:04 PM »
I like the technique by which you notched, but I'm not sure why you are notching the studs in the first place.

Is it to bear a 'let-in' floor joist?

If so, it appears to be a code violation under the International Residential Code 2003 (Washington State's Code) on a number of counts.

The Code limits how deep walls studs can be notched.

For bearing walls, the maximum depth of the notch is only 7/8" for a 2x4 and 1 3/8" for a 2x6. (Section R606.2 Drilling and Notching Studs).

 This creates a problem because floor joists need to be borne on a minimum of 1 1/2" of lumber. This means according to Code, you cannot do what you just did because A) it weakens the bearing wall joists too much to allow them to carry the weight of the floor and roof system from above from overnotching and B) it does not allow for a deep enough notch at 1 3/8" for the joist to be properly borne. Bearing joists need to be carried on at least 1 1/2" of wood. (Section R502.6)

Be interested to have this explained in further detail because it appears that what you may have done is a serious code violation and may have seriously compromised the structural integrity of the building.

Perhaps I misunderstand.

Could you explain in better detail what you are trying to do and why?

« Last Edit: April 13, 2006, 05:55:06 PM by manhattan42 »

Amanda_931

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Re:  letting in ledgers for floor joist.
« Reply #9 on: April 13, 2006, 06:18:15 PM »
Is it really a notch if you fill it all up with basically the same material you took out of it (even if it's going th opposite direction)??

I don't know.
« Last Edit: April 13, 2006, 06:59:04 PM by Amanda_931 »

peg_688

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Re:  letting in ledgers for floor joist.
« Reply #10 on: April 13, 2006, 06:35:24 PM »
Quote
I like the technique by which you notched,

   Thanks  :)


     but I'm not sure why you are notching the studs in the first place.

    


  [highlight]  For a loft area , 2x12 joist , 4x6 fir post / and 4x6 LSL post 24" oc. as per architectural drawing , BTW the owner/ person who designed the place  is a Professor of Architecture , as is his wife ,at a major west coast Univ. .

   The plans have been approved/ stamped/ added to etc. by a  PE Registered in the State of Wa.  to spec.s of  

     - IBC '03' and IRC '00'  

      -Exposurer B
  
      - 85 mph winds
  
       -Seismic Design Cat. D1

  The plans have pasted code check for the city they where submitted to.

  Const. has followed the plans" to the letter" with no major changes to  the drawing/ approved plans  detail.

  17 [size=18]PAGES[/size] of engineering
[/highlight]
    
Is it to bear a 'let-in' floor joist?

No,  a 2x6 SPF ledger is let in.

  The joist run 90° to the ledger.  

  Joists run N/S , ledgers runs E/W

  
If so, it appears to be a code violation under the International Residential Code 2003 (Washington State's Code) on a number of counts.

The Code limits how deep walls studs can be notched.

For bearing walls, the maximum depth of the notch is only 7/8" for a 2x4 and 1 3/8" for a 2x6. (Section R606.2 Drilling and Notching Studs).

   That may be why the post are 4x6 LSL and 4x6 D. Fir



 This creates a problem because floor joists need to be borne on a minimum of 1 1/2" of lumber. This means according to Code, you cannot do what you just did because A) it weakens the bearing wall joists too much to allow them to carry the weight of the floor and roof system from above from overnotching and B) it does not allow for a deep enough notch at 1 3/8" for the joist to be properly borne. Bearing joists need to be carried on at least 1 1/2" of wood. (Section R502.6)


  

Be interested to have this explained in further detail because it appears that what you may have done is a serious code violation and may have seriously compromised the structural integrity of the building.

Perhaps I misunderstand.

Could you explain in better detail what you are trying to do and why?


    I'm following the approved plans  ;)



 

  The staging is sitting on top of the 2 x12 D, Fir joist , top of joist 9' above lower sub floor , as per plan , resting on let in 2x6 SPF ledger, nailed  to ea. stud and or 4x6 post with 2 ea. 16d nails .  Joist are nailed to ea. side of the 4x6 posts with4 ea . 16 d nails staggered as per plan.

  You may be able to see the top plate on the right hand side is a 4x6 D.F. beam, this acts as both T/P and headers for a few windows 8-)  

  

  2x10 D.Fir rafters 24" OC , with 2x12 DF ridge board , nailed with 4ea, 16d nails .

   Nice cuts , Eh ;)

  Hopefully this is enough info.   ;)

  PEG
« Last Edit: April 13, 2006, 06:42:39 PM by peg_688 »

glenn-k

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Re:  letting in ledgers for floor joist.
« Reply #11 on: April 13, 2006, 06:41:13 PM »
What is the solution for this, Manhattan, because this has been a standard practice in balloon framing for a hundred years.  In the old days they used to use a 1x4 instead of a 2x4.  Does the UBC permit this as many of the areas around here are still using UBC, since they didn't like a lot of the changes in the IBC.

Looks like PEG has his covered but it is still common practice to do this I believe.

Nice cuts is right PEG - I never get mine that close when cutting with a chain saw.  I find I can make them look better by taking the picture off to the side so the the sunlight doesn't show through the cracks. :-/

« Last Edit: April 13, 2006, 06:48:28 PM by glenn-k »

peg_688

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Re:  letting in ledgers for floor joist.
« Reply #12 on: April 13, 2006, 07:47:00 PM »
Quote

  
Nice cuts is right PEG - I never get mine that close when cutting with a chain saw.  I find I can make them look better by taking the picture off to the side so the the sunlight doesn't show through the cracks. :-/



  [size=12]   ::) ::)  Hoy, we got some  work to do here  ::) ::)[/size]

manhattan42

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Re:  letting in ledgers for floor joist.
« Reply #13 on: April 14, 2006, 02:07:55 AM »
Amanda_931 asked:

"Is it really a notch if you fill it all up with basically the same material you took out of it (even if it's going th opposite direction)?? "

To my knowledge, it is still a notch and weakens the bearing studs by creating kind of a 'hinge' point at which lateral forces could bend or ultimately snap them.

The lateral force can came from wind sheer, snow loads on the roof, excessive loads on floors, etc...

Excessive bending can cause the lumber to split, further weakening the structure.
« Last Edit: April 14, 2006, 02:46:23 AM by manhattan42 »

manhattan42

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Re:  letting in ledgers for floor joist.
« Reply #14 on: April 14, 2006, 02:32:46 AM »
PEG688:

Thanks for the further input.

Under IRC 2000, notching of dimensional studs is limited to 25% of the depth for bearing walls and 40% for non-bearing walls. I observed what appeared to be notches deeper than the 1 3/8" maximum for 2x6s which is what prompted my questions.

Engineered lumber notching and boring is determined by the engineered lumber manufacturer, not the code.

Since the plans have been stamped, it is possible that the structure may have been designed under a different approved standard, such as the National Design Specification or International Building Code rather than the International Residential Code.

The IRC also permits other engineered designs and methods.

BTW, I wasn't questioning you or your work. It is impressive.

Just wondered what the specs were because some of what appeared in your photos raised questions.
« Last Edit: April 14, 2006, 02:49:10 AM by manhattan42 »

manhattan42

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Re:  letting in ledgers for floor joist.
« Reply #15 on: April 14, 2006, 02:44:55 AM »
glenn kangiser asked:

"What is the solution for this, Manhattan, because this has been a standard practice in balloon framing for a hundred years.  In the old days they used to use a 1x4 instead of a 2x4.  Does the UBC permit this as many of the areas around here are still using UBC, since they didn't like a lot of the changes in the IBC."

Balloon framing is still allowed under the International Residential Code as is let-in bracing of walls. The key is to not notch the studs more than 25% of the depth for 2x4 bearing walls or more than 40% for 2x6 bearing walls.

Maximum notch depth of a nominal bearing 2x4 stud is 7/8", so 3/4" let-in boards are still acceptable today just as they were back when. With older true 2" by 4" studs, the permissable notch depth would have been deeper.

Using nominal 2x lumber as a let-in is not allowed under IRC today because it notches the studs deeper than permitted.

I'm not really familiar with the UBC which California currently uses.

But California has opted to replace the UBC with the full compliment of International Codes beginning in 2006, and is in the process of implementing them once the State makes amendments to these model codes to make them more applicable to the California environment. Expect California's UBC to be obsolete by next year.

« Last Edit: April 14, 2006, 02:45:40 AM by manhattan42 »

glenn-k

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Re:  letting in ledgers for floor joist.
« Reply #16 on: April 14, 2006, 05:13:03 AM »
Thanks, Manhattan.   That makes sense.

jraabe

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Re:  letting in ledgers for floor joist.
« Reply #17 on: April 14, 2006, 07:34:02 AM »
Good to have someone around here who knows the code issues. For most owner/builder/designers the mere mass of regulation-style text overwhelms potential understanding - that and the fact that it can seem to be always changing and subject to interpretation.

It is very helpful when someone like Mr. NY here explains it in a way that makes perfect sense.

peg_688

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Re:  letting in ledgers for floor joist.
« Reply #18 on: April 14, 2006, 04:02:14 PM »
Heres a few more photos Manhatten , and by the book you are right ,1 3/8" is the max let in for a 5 1/2" framing member.  Even on that is 3 1/2" in thickness :o as in a post.

  [highlight]This project with the engineering goes beyond the basic "book" code . [/highlight]  I wonder why they chose 1 3/8"  :-/Knowing that would rule out dementional lumber ,IE , 2x4 / 6 for the ledger.  

 I think you'd agree that the 1/8 " difference is moot , it would not be  the 1/8th Inch that would break the camels back , so to speak :o

  That being said  from a inspector stand point some where you have to have a # / rule to go by . This one seems to me to not make any sense, a 1x4 on paper would work but in application I'd not trust a 1x4 common fir to do the job , so a 2x4 would be the natural next step as 5/4 material is not avaible in framing type stock .  Buying a 5/4 x 4 D. Fir board at about $3.00 a  foot would be a hard sell.  

 So either the writers of the new code want to make this type of semi" ballon " framing impractical  for cost and compliance or they just screwed the pooch by going with the hard and fast 25% rule ::)

  

  Close up of the nail pattern for attaching the 2x12 to the 4x6's.

  

  General view of joist and ledger.


  Views of joist to post detail.

 
  



  


  


  View from my office this week :)

  

  That sail boat might be a better office  ;)

  PEG
« Last Edit: April 14, 2006, 04:37:41 PM by peg_688 »

JRR

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Re:  letting in ledgers for floor joist.
« Reply #19 on: April 14, 2006, 04:30:57 PM »
Would it be acceptable to use a vertical 2x nailer ("jack-post", "crutch", ?? ... I don't know the correct term) attached to the inside face of the stud to support the joists?  This would eliminate the ledger and the letting-in.  If acceptable, would such an element have to extend all the way down to the sill ... or would the shear loading on "x" number of nails or screws be sufficient?

BTW, great looking framing PEG!
« Last Edit: April 14, 2006, 04:33:38 PM by JRR »

peg_688

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Re:  letting in ledgers for floor joist.
« Reply #20 on: April 14, 2006, 04:53:59 PM »
Quote
Good to have someone around here who knows the code issues.

    [size=12]  Yup :) [/size]

   For most owner/builder/designers the mere mass of regulation-style text overwhelms potential understanding - that and the fact that it can seem to be always changing and subject to interpretation.

   [size=12]  Yes it is a PITA ::)  [/size]

It is very helpful when someone like Mr. NY here explains it in a way that makes perfect sense.

    [size=12] Now on this specfic issue, 1 3/8 " max depth as apposed to 1 1/2" depth  ::)  I can't say that "MAKE SENSE", ::) seems nit picky , bean counter , anal retentive to me  ::)  That 1/8"x5 1/2 " taken out is infinitesimal ,  there is still a 4" net of material left undisturbed .

     And of course that is not manhatten's fault ;)

    PEG  
   [/size]

Amanda_931

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Re:  letting in ledgers for floor joist.
« Reply #21 on: April 14, 2006, 04:59:41 PM »
Are y'all having to put diagonal bracing to keep the whole building from tilting?  Or is that just belt-and-suspenders?

(Manhattan could be Kansas)

this last lot of pictures told me exactly what was going on.   Getting pictures that do that really is an art form.  Good work.

peg_688

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Re:  letting in ledgers for floor joist.
« Reply #22 on: April 14, 2006, 05:58:50 PM »
Quote

  Are y'all having to put diagonal bracing to keep the whole building from tilting?  Or is that just belt-and-suspenders?

  [size=12]   Amanda the old diagonal bracing thing around here is long gone  :) It was also a PITA, IMO.    These days we have Brace Wall Panels , BWP , and Alternate BWP  ABWP, Interior BWP IBWP , etc  

  All these different panels have to be  [highlight]at least[/highlight] 1/2 CDX or 7/16 OSB .  Some times we sheet both sides . The nailing is generally 4 "OC on the edges and 6" in the field  althought I have seen 2" OC all edges and 4" OC in the field . You'd think all those nails would degrade the lumber / split the crap out of it , and you'd be right , BUT the book/ engineers want the nails , generally 6d gun nails .   Unless they go into the new ACQ lumber then the nails have to be Galv.

  Not much for a old carpenter to remember these days  :o

  All sorts of different "Hold downs " from Simpson . They must have a boat load of lobbyist we use more metal straps , hold downs , clips , than ya can shake a stick at.   ''  These straps are generally nailed about ever 2 to 3 inches with 16d nails  :o Each strap generally have the nail size and ya fill all the holes with the "right " nail size.

  All that hardware drives up the cost, they contend these places will hold up in a quake , some day we'll see  :o :o  or some one will ;)  I hope not me  :)

  A break down of what Katrina did to newer homes would be nice[highlight] , IF they build down south like we do here in PNW[/highlight] .

   I doubt they do as quakes are not suppost to happen down there , but high winds / hurricane / tornados do about the same thing I would think .    
  [/size]

[highlight]
  Another thing eng. don't figure in is how the sheathing is applied , as in,, does the crew break the sheets so they over lap the box sill so the" hinge point " is supported by the sheathing , or is it just put on willy nilly , cut up,,, not lapped so window headers , plates , changes in levels are thought about.

  As they can't control that they slap a strap , or a clip , or a threaded rod from a bolt inbeded in the concrete to a coupling to a rod thru the floor , up the wall cavity thru the top plates toa big washer and nut to pull hold the whole works together :o :o[/highlight]


 this last lot of pictures told me exactly what was going on.   Getting pictures that do that really is an art form.  Good work.

  [highlight]Ya a picture is worth a thousands words  :)  So I'm a artist ;D jee I wonder if I can charge more  ;D

  Thanks  :)

  PEG[/highlight]

   [size=12]  PS I forgot to change color so to not confuse your quote I highlighted , to lazy to go back and redo the whole works  :-[  [/size]
« Last Edit: April 14, 2006, 06:08:40 PM by peg_688 »

peg_688

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Re:  letting in ledgers for floor joist.
« Reply #23 on: April 14, 2006, 06:06:47 PM »
Quote
 


  Would it be acceptable to use a vertical 2x nailer ("jack-post", "crutch", ?? ... I don't know the correct term) attached to the inside face of the stud to support the joists?  

  [size=12]    I'd call that a  trimmer like under a header, it would have to go to the plate full bearing . It would work , but in this case the look is for the two joist pairs to be exposed , finished natural .  so you'd need one on each side of the 4x6 post.   It might work , but again these plans don't call for it that way. Good question though :)    [/size]


 
  is would eliminate the ledger and the letting-in.  If acceptable, would such an element have to extend all the way down to the sill ... or would the shear loading on "x" number of nails or screws be sufficient?


   [size=12]See above  :)    [/size]

BTW, great looking framing PEG!


  [size=12]  Thanks  :) [/size]
  

manhattan42

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Re:  letting in ledgers for floor joist.
« Reply #24 on: April 14, 2006, 06:22:25 PM »
John Raabe said:

"Good to have someone around here who knows the code issues. For most owner/builder/designers the mere mass of regulation-style text overwhelms potential understanding - that and the fact that it can seem to be always changing and subject to interpretation.
 
It is very helpful when someone like Mr. NY here explains it in a way that makes perfect sense. "


Well, I'm not only a code official, but a builder as well.

I have to try to make sense of the codes on a daily and very practical basis. :o ;D
« Last Edit: April 14, 2006, 06:46:00 PM by manhattan42 »

 

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