letting in ledgers for floor joist.

Started by PEG688, April 10, 2006, 10:08:42 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

John Raabe

I would second PEG's suggestion. A beam and deck ceiling will give a sense of a higher ceiling height and you can often go to 4x joists spaced 36" to 48" o/c. The downside is that the floor is a bit noisier transmitting impact noise below, and, it can cause plumbing issues when traps want to be hidden in the joist cavity.
None of us are as smart as all of us.

Redoverfarm

pericles just to give you some idea of the look that is what I did on my cabin.  While most of the pic's are of the beam to log it will still give you some idea.  I just didn't take any pic's of the framed room with the beams and flooring.  If you want to take a look I will but the post below.  If I think of it I will take a pic of the framed room to give you some idea.  The first page (most recent) is mostly of the floor and ceiling if you care to look. 

http://countryplans.com/smf/index.php?topic=3613.msg49416#msg49416


MountainDon

I remember admiring that, John

What was the span approx? 4xwhat? and what is the decking; 2x4or6 T&G?
Just because something has been done and has not failed, doesn't mean it is good design.

Redoverfarm

Don it ws 36"OC and was 2X6.  Actually the floor above only covers 5".  The 5-1/2 minus the T&G.  It is standard V groove on the ceiling.  The only span tht is larger is where it meets the chimney.  48" there on the kitchen side.  The foyer worked out to 54" to the chimney. I had an extra beam and put it in between that.  Didn't feel comfortable with that amount of span since the steps emptied onto there(landing).

Redoverfarm

pericles this is the way I did my ceiling beams/joist in my loft.  Some may disagree with the method but I think it works very well.  Adding 2X support blocks to the studs(full thickness). Then placing two header blocks (stud to stud) and allowing the beams to sit on them.  I finally remembered to take my camera this time.  Hope it helps.






PEG688

#80
 I disagree , those 2by blocks under your "header" should go all the way to the bottom plate . You are essentially counting on sheer strenght of the nails to hold the "headers" up.

Yes it will work , MTL, BUT it will not pass inspection and they may settle some over the years.

That same situation can be found in may old balloon framed buildings , generally the floors are way out of level due to unequal settling / shifting , as some nails hold good , some not so good.

Much better to run full length "trimmers",  other than that she's cherry.  :) 
When in doubt , build it stout with something you know about .

Redoverfarm

Peg you are probably right in that they "may" settle.  Given the construction practices now it is less likely to occur.  Floor joist on 16OC as well as wall studs. The 2X blocks are approx 16" and nailed as least 6 times and some more often from the opposite direction.  I was thinking about this when I was doing and angles the nails toward the ceiling.  The header is also nailed to the studs.  If a ledger were set in the partition it too could settle by the failure of the footing or foundation and cause the same problem irregardless of long trimmers.  I guess we will just have to wait and see.  I feel pretty good about the foundation as it is on solid shale, 12" X 24" footing, 8" block. 

Thanks for your insight. 

PEG688


Modern foundation such as yours do not "commonly " fail , your ceiling joist/ beams are 32 " OC. You have mixed and matched old "common" failure  points / short comings  with newer / better const. ,( your good foundation ),  practices. This  re-introducing common balloon const. failure points  , IE joist only supported by nail strenght.

My desire here is not to make you look bad , but to point out to others that , as you put it, " works very well" , in fact is  old method that has failed consistently in the past. Other may choose to do the same thing , I'd expect the same result I've seen in 50 to 100 years , sagging unlevel / uneven loft floor.

Wood moves , drys out , splits , twists , etc . All those , did you say 6 nails , will exacerbate those  tendencies to split , twist etc. 

  It may be fine for your life time , but to "build green " IMO means to build a wood framed structure that will last at least 3 life times (250 years or more). On the subject of "green building " using products that are recycled  as such is fine BUT overall longevity of the structure SHOULD play into the green title.

Now let me get down off this soap box.  ;)       
When in doubt , build it stout with something you know about .

MountainDon

I guess we'll have to check back in a 100 years or so...
Just because something has been done and has not failed, doesn't mean it is good design.


John Raabe

Just for reference, a 16d nail has a design shear value of 128 lbs. A 10d about 75 lbs.

If that wall is still open I would squeeze in a couple of after the fact cripples for insurance.
None of us are as smart as all of us.

Willy

Quote from: John Raabe on April 18, 2008, 12:47:18 PM
Just for reference, a 16d nail has a design shear value of 128 lbs. A 10d about 75 lbs.

If that wall is still open I would squeeze in a couple of after the fact cripples for insurance.
I would have to agree on that. 2 cripples even crummy ones would go a long ways for strength on those beams. Stopping just a tiny little settling will be worth it not having sheet rock mud later cracking on the taped seams. Mark

Jens

Quote from: pericles on April 10, 2008, 09:03:26 AM



Eventually we'd like to insulate though, and after that, we'll throw vertical 1x4s from the floor to maybe 3.5 feet, and OSB above that, with some sort of molding between the two.  I'd like to maybe prime (and prime and prime) and paint the OSB white and stain and the 1x4s and molding. 

Jack Larkin
jlarkin1@law.villanova.edu
I would suggest plywood instead of the OSB for the upper walls.  Will paint better, and won't offgas.  Smoother too.  Don't forget to let-in (cut into the face of the studs) some 1x4's for all of the verticals on the wainscot to fasten to.  Could be nailed to the face as well.  Or you could cover lower section of wall with plywood also, giving 100% nailing surface for the wainscot, as well as blocking drafts, and pest infiltration.  Use T&G, or shiplap for the boards, and you won't notice the wood movement so much. 

Peg, I totally agree with you about the green issue.  I hate seeing MDF and particleboard used everywhere (especially bathrooms and kitchens) on these DIY shows simply because it is green.  What is so green about re-trimming your house, or replacing cabinets in 10 years because the wood swelled up crazy?

Manhattan, I think that nailing the joists to the sides of the studs, would reduce the tendancy for them to want to snap, as they would be fastened above the notch.  In theory (for my mind at least), this actually seperates the wall framing into two sections, while still having >2/3 of material connecting the upper and lower studs.  The cathedral ceiling, probably has a load bearing ridge, so shear forces would not be exerted by the rafters, and the joists would want to keep the walls from spreading even if the rafters did push out. 

Peg, I have thought about gang cutting the studs many times while reading on this forum over the last few years, but somehow never saw this thread!  In the production world I used to frame in, the boss would shoot us for using a router for anything but cutting out door and window holes in sheeting.  We would have done it the same way the top of a rafter gets let in for an outrigger...two crosscuts 1 1/2 deep, turn board on side, set edge of baseplate (1 1/2 inches from blade) on edge of stock, and plunge in connecting the lines.  Have to overcut a bit, and I'm sure there is data on this from all the engineers out there as to why this shouldn't be done, but thats how we would do it.  Or just the two kerfs, and three taps with a sharp chisel to clear the waste (two light taps to set the line next to the sawkerfs, one sharp cleave in between to finish the job.

I think I would trust a 1x4 let in as a ledger...better 1x6 though, as I am pretty sure that the shear force of the joist, which is nailed to the side of the stud, wouldn't actually be enough to comprimise the 1x when it is that close to the stud.  I would just run the ledger on the face of the studs, or let in 3/4" and use it as the half beams for a coffered ceiling underneath a drywalled ceiling.  Then you can have joist bays filled with insulation, electrical, plumbing, and HVAC. 

I think I covered everything I wanted to say there...whew!  Tired now!
just spent a few days building a website, and didn't know that it could be so physically taxing to sit and do nothing all day!

Zavoot

I'm new to this thread and the site but I'm facing the same dilemma!
I trust the let in and don't think the extra 1/8th of an inch of let in will ever be a big deal. BUT - I have access to a planner and why not just run those 2x4s (1 1/2 by 3 1/2) through and make my own 5/4 boards - they are still framing grade ? ? ? and I don't need all those extra trimmers.
Live simply, seek justice, show respect

PEG688

Quote from: Zavoot on April 27, 2009, 08:48:54 PM


I'm new to this thread and the site but I'm facing the same dilemma!
I trust the let in and don't think the extra 1/8th of an inch of let in will ever be a big deal. BUT - I have access to a planner and why not just run those 2x4s (1 1/2 by 3 1/2) through and make my own 5/4 boards - they are still framing grade ? ? ? and I don't need all those extra trimmers.



All you need to do is take a couple , maybe one depends on the planer pass to meet the prescriptive code , 1 3/8" thick and your golden , no need to plane it down to a net 5/4" which is 1" net BTW.  Maybe take it down to 1 1/4" net.   

  You are using 2x6 studs right? (Net 1 1/2" x  5 1/2" stock)


  Jen's the saw cut pass -by deal I don't like for obvious reasons  especially on this type situation , sure to knock in a rafter look-out or some such , but not on let in bracing , or stair jacks.  The router made fast work of it , you need the right router and the right type of bit but it does a fine job.


  Fast sloppy framing does NOT impress me, fast clean framing does , few do the later.  Set myself apart from what everyone else does has kept me busier than most for many years.


  The architect on the big window job told the project manager he'd never seen the level of detail and care we've put into that house on the outside, I feel pretty good about that.

And just today I contacted another local architect that I'd worked for in the past to let him know where I was working now and he was happy that he could contact the company I work for his next project.

Good work goes further then the street, at least thats been my experience.

  BTW Glenn banned ole Manhattan not long after this thread was started , he didn't play well with others, as Glenn put it.  ;)
       


 
     
When in doubt , build it stout with something you know about .


MountainDon

Quote from: PEG688 on April 27, 2009, 10:22:43 PM
And just today I contacted another local architect that I'd worked for in the past to let him know where I was working now and he was happy that he could contact the company I work for his next project.
     

Great to hear that PEG.  :)

Just because something has been done and has not failed, doesn't mean it is good design.

glenn kangiser

Work will always follow you around, PEG.  You are above doing anything less than the best job you can.  People talk. d*

For ol' Manhattan, he was the inspector from hell, right next to the god of the underworld.  I told him we could use his advice but he would have to stop attacking the members of the forum.  He banned himself as he would not follow my requests.  I commonly either straighten his type out on my jobs or get rid of them if necessary through major unrelenting complaints to their bosses.

I had one who would pass things in the morning, get drunk at noon, and make us tear apart everything in the afternoon.  A time or two of that and he was begging me to stop the calls to his boss - I suggested to his boss that I may take him to court.  Bill, the drunk, called a special meeting at the job to start over -- he was fine after that.

We are all glad you can find or make time to instruct us here on the forum, PEG.  Thanks. :)
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

PEG688

Quote from: glenn kangiser on May 03, 2009, 07:51:22 AM



For ol' Manhattan, he was the inspector from hell, right next to the god of the underworld.  I told him we could use his advice but he would have to stop attacking the members of the forum.  He banned himself as he would not follow my requests.  I commonly either straighten his type out on my jobs or get rid of them if necessary through major unrelenting complaints to their bosses.



Your right , he did it to himself. BUT that way of looking at it / spinning it / phrasing it , diminishes your power base. You won't make much of a dictator / king / power broker  should the situation present itself  ;)



   
When in doubt , build it stout with something you know about .

glenn kangiser

I offered him a chance to educate others if he would.  Don't worry... I could have easily destroyed him if necessary... d*

I can be cold blooded without a second thought when required... you only see my nice guy side.... rofl
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

PEG688

When in doubt , build it stout with something you know about .

glenn kangiser

"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.


OlJarhead

OK I was led here by another post and began doing this:  ???

If the plans called for 2x4 studs (which would work) but you chose 2x6 studs (more insulation) then would not, in theory the point be moot?  After all a 2x4 stud is really only a 1 1/2 x 3 1/2 stud and the 2x6 stud is 1 1/2 x 5 1/2.  Therefore, notching 2 inches out of the 2x6 stud would leave you the same 3 1/2 inches of stud you would have had with the 2x4.

Now, of course, you can probably use some engineering formula to determine the difference between a 3 1/2 inch stud notched 3/4" to 2 3/4" width vs. a 5 1/2 inch stud notched 1 1/2" to a 4" width but I'd venture that the 4" width is stronger then the 2 3/4" width any day.

In which case it's nothing more then a case of stupid regulations for the purpose of controlling someone or something that may not need to be controlled.

Codes are often too blanket because they are attempting to meet all cases and situations (like speed limits on interstates) but in the practical world...well let me put it this way:  If it is safe for a Mack Truck pulling 20,000 pounds of stuff in it's trailer to travel at 65 miles per hour on the highway I can assure you that is also safe for a Ferrari F40 to travel on that same stretch of road at 100 miles per hour.  The Ferrari will, in fact, still turn faster, break faster and excellerate faster then the 65 MPH truck as well as avoid accidents faster but regulations (speed limit) determine that they are equal for the purpose of driving.

Thus, we find ourselves looking at codes telling us we must have 2x6 walls for example, while sitting in a nearly 60 year old home (two stories) with 2x4 walls which clearly take the weight of the second floor....

Native_NM

I think the issue is more complicated than that.  I have done a fair bit of reading today on the subject.  It seems the bigger issue is that notching more than a certain percentage might weaken the stud and lead to fracture or failure.  Based on code, you are correct that a 2x4 would be adequate by itself for this plan.  The issue (and I don't know the answer) is if an over-notched 2x6 is as strong as a full 2x4.  Stated another way, an over-notched 2x6 might be weaker than an un-notched 2x4 even though there is more "meat" on its bones.

I'll let you know what the good doctor (PhD engineer and PE) comes back with.  I sent him a link to this specific thread. 
New Mexico.  Better than regular Mexico.

OlJarhead

Quote from: Native_NM on June 03, 2010, 06:36:58 PM
I think the issue is more complicated than that.  I have done a fair bit of reading today on the subject.  It seems the bigger issue is that notching more than a certain percentage might weaken the stud and lead to fracture or failure.  Based on code, you are correct that a 2x4 would be adequate by itself for this plan.  The issue (and I don't know the answer) is if an over-notched 2x6 is as strong as a full 2x4.  Stated another way, an over-notched 2x6 might be weaker than an un-notched 2x4 even though there is more "meat" on its bones.

I'll let you know what the good doctor (PhD engineer and PE) comes back with.  I sent him a link to this specific thread. 

Thanks!  I'd be VERY interested in the answer.
Erik

diyfrank

So if notching a 2x6 1 1/2" is weakening a stud to the point it could split and have less strength whether it be compression, shear or what ever then a  2"x4". Would there be any different, stronger, weaker   then a 2"x4" with a ledger nail/ bolted to it and then scabbing on a 2"x2" under and over the ledger to help support the ledger and bring the combo out flush with the 2"x6" studs not supporting a ledger?  ???
It just seems like one way or another there should be a way to do this.  
Home is where you make it

Don_P

The codebook is referencing the NDS on notching restrictions. The NDS is assuming graded lumber. One thing I can think of is defect sizes vary with lumber dimensions. Assuming the driver of the ferrari knows to look for knots in the notch area then the 2x6 stud is stronger. If it's a dumb kid driving a ferrari at 100 mph I'd buckle up.

I'm not worried about the notch or ledger dimensions if they were being done as per the drawing in the codebook, a box on top of a box. That isn't what is being done here. Studs notched on their tension face are running 2-4' above floor level where rafters with ties in the upper third of the roof height are supported by them. That is where my concern level kicks in. I'd also be interested in an opinion on putting a 2x ledger on the outside compression face of the wall and then running sheathing over the notched area.

A traditional dutch barn is somewhat similar. They are built with H frame bents with rafters supported by the upright legs of the H. There have been 3 threads relating to failures in the past year on the TF Guild forum. The latest was a tour of multiple historic softwood barns. All had some degree of failure in that area.