deck ledger fastening to balloon framing
dieselpig
| Posted in Construction Techniques on
I’m building a beautiful 3500sq ft cape in MA. A twenty two foot long section of the back wall is a twenty foot high, 2×6 balloon framed wall full of glass. There is a two story deck attached to this wall. What would be the best method of attaching the deck ledger for the second deck floor to this wall. Lags into studs? Blocking between stud bays with lags? Neither of these seem to be very good and it’s all the GC and arcitect came up with (I’m a sub). Also, the rest of the house is BCI’s… is it ok to lag into these as well? Will it hold? I have the green light from the GC to just lag, so my
Replies
Is that green light in writing?
Are the archys palns and specs detailing the lags only?
In a situation lik ethat, I let the ledger in to the studs.(I'm assuming you mean a second floor interior level) But with a wall full of glass, you weakebn the few continuous studs there are. Sounds like a job for Super Structural Engineer!
Unless either the GC or the Archy is a qualified struc engineer, I'm not sure what their opinion is worth.
I have seen engineered details with lags but that presents another problem. The lag heads protrude right where the studs are. That is the same place that I like to locate my joists so there is conflict there making it hard for me to follow consistant layout. Keeping the voids lined up helps for the trades coming to rough in plumbing and electrical.
Excellence is its own reward!
Piffin
Would like your opinion on this scenario....
What problems would arise if the subcontractor lag screwed a support beam (instead of a ledger board) to the 2X6 studs. The joists would sit on top of this beam and the studs could be thru-bolted into the face side of each stud. This is same principal of framing a second story using balloon framing ( a let-in ribbon with floor joists nailed perpendicular to studs)
In this case, the lag bolted beam is the "let-in" but without cutting the studs. Thru-bolts replace the nails where floor joists (deck joists) tie in to studs.
What do you think?
Davo
Piffin,
Thanks for replying. I should have been a little clearer. The two story porch (not actually a deck as it terminates with a roof) is exterior. Since I had the "green light" from the GC I went ahead and framed the whole thing today and just nailed the ledger to the studs so I could continue framing while hoping a better solution would come to me. The arch told me to just block every other stud bay on the inside of the wall and run my lags through the ledger into the blocking. I asked what was to keep the entire thing from sliding (theoretically) right down the stud bay? He just shook his head like I was the insane one and told me, "that's not going anywhere". I find that I have a hard time comunicating with archs, engineers and such because I am young and they assume I haven't a clue. My solution to the entire problem was to beef up the ledgers (all three of them...first deck, second deck, and cieling) basically build a beam and add posts against the house all the way down to additional footings. I was told it was over kill. To answer your other question, none of this is in writing. Not even an original written bid. This is how my boss likes to operate and the GC complies. There is no detail for the proper attatchment on the prints. The GC seems totally comfortable with whatever the arch comes up with, so I will probably end up just doing it their way, but I would like to know how to handle this situation properly in the future if not on this job. Additionally, any thoughts on attatching ledger to BCI's "ribbon" type band joists?
Dieselpig,
Ask the architect if he would mind if you nailed some inside corner hangers on the inside of the wall nailed through the 2x6 and through the back of the sheathing and into the ledger.
Joe Carola
Dieselpig,
The architect said to put blocks in between and lag through the ledger.
I forgot to mention that I've never seen or done that befor.
I would rather lag into the 2x6 instead, just make your your dead center when you do it.
You could also do like I said above with the inside corner hangers.
I know you said it's a window wall. Does your ledger come anywhere near a header?
You could also run your first beam past your ledger and into the house. Notch out your first 2x6 of your corner post whatever the thickness of your deck beam is and that will hold up your ends.
On walls that high I use 5 - 2x6's for the corner anyway.
Let me no what you think.
Joe Carola
What Davo said would most likely work well in certain style houses.
Letting the ledger in like I mentioned would not be my choice for an exterior deck. I'm curious now What is going to keep water out of the wall if you are sticking the ledger directly to the studs and blocking?
BTW, framer Al is right about laging direcly to the studs instead of to interspersed blocking. You do need blocking for firestop spacers in a balloon wall amny way so I don't understand why the archy is only saying every other one. Either there is something else going on here or he doesn't know beans about structure. Why is this specified to be a balloon wall anyway? A header beam would stabilize the wall make firestop and solve this dilemma all in one!.
Excellence is its own reward!
Piffin,
He could have also put the window header maybe a 5-1/2" x 11-7/8" microlam right behind the ledger for something solid to bolt into if the architect doesn't want him to bolt into the studs.
Then he could put another header above the real window opening.
Just a Thought.
Joe Carola
Right Joe, sorry I said Al earlier - confused with Al Constantine..
Excellence is its own reward!
Oh yeah, and thanks for helping out guys! Any ideas on ledger to engineered band joist attachment?
Okay, let's see if I can answer some of your questions...the wall is 2x6 balloon framed because the interior is a two story open foyer type "great room", with a slider going out to the first tier of the porch, stacked above the slider is a large (6'6") window. This stack is flanked by single mulls w/ transoms, also stacked...ie lotsa glass. Headers are 2x12 over single mulls and 5 1/2x11 7/8 versalams over the slider and center window. I think I may bring the digital camera to work tomorow just to satisfy curiosity since I am obviously not explaining too well. To answer the other question, the arch said to only block every other bay for the ledger attachment so that the blocking could be "securely" nailed through the 2x6's on either side of the blocks...follow me? I guess he figured the nails will hold up the blocks, the lags will hold the ledger to the blocks, and the ledger and hangers will hold the exterior joists up... which, to me, adds up the the original nails holding the blocking basically holding up the porch which is two stories and a roof load!!Although the roof load is obviously more over the posts and beams on the front of the porch. In addition none of the headers fall in the path of the exterior ledger, so lagging to the headers is out of the question. As far as path of water goes, I built the entire 2x6 wall on the deck, sheathed it, Tyvek, roll flashing, and attatched the ledger before raising it with pole jacks and my lull. I hope that this helps clarify things.
I think I can see it. If you want to stir things up, tell your GC or the archy that we'll all laughing (Shouldn't be laughing because people get killed every year on this kind of thing) at the archys suggestion that the shear strength of a few sixteens in the blocking will hold the deck up.
Better not, Just lag it good as you are allowed to..
Excellence is its own reward!
Piffin,
Here we go again with these architects ;-)
This poor guy is trying to do the right thing.
Joe Carola
I've just started an addition on an old two story ballon frame. Had a structrual engineer look at it. Solid blocking between the studs, then he suggested, but not required metal strapping wrapping around the corners, then lagging a ledger on top at 32'' oc. That was for attaching a truss system against the house. Hope this might help, sounds similar.