Hi All:
I’m building a deck for a homeowner (aka “Momâ€) who refuses to allow a ledger to be bolted on to the house. Built several decks before but never one that’s freestanding. The plan (some might call it contraption) I’ve come up with is to use 2X6 framing for girders and joists connected to 4X4 posts. Everything is up to code (joist/girder span, 16†OC, load limits, footing depth/diameter, etc.) EXCEPT perhaps for the way I’m hanging joists to the closest-to-the-house girder. Please take a look at the attached drawing for detail.
My concern with this “false ledger†scenario is that the inside 2X6 will be taking most of the joist/decking/live load while the outside 2X6 (which runs uncut for 18’) won’t be carrying its share. You’ll notice in my drawing that I’m bolting 4X4 blocking (every 3’ or so) between the two 2X6’s to hopefully even out the load. Wishful thinking? You might be wondering why I’m not using beefier lumber for the girders (2×8’s or 4X6’s) — the problem is that I’m working with only 15†of distance between grade and decking top. I could reduce the pier height down to almost grade to accommodate bigger wood, but moisture is a major concern as the decomposed-granite soil around here drains about as well the sink at that old truckstop out on Route 40.
If any of you pros out there have any suggestions and/or “you-gotta-be-kidding-me†observations, I’m all ears. Thanks for your help.
Flash
Replies
If you had more height to work with a more logical approach would be to use two beams parallel to the house, at about the 1/4 and 3/4 points, then cantilever the joists on top with rim joist all around. But you do seem to be stuck in this case. (At least you're stuck if there isn't much slope. If there's a lot of slope then there might be room for a cantilevered design.)
Probably the simplest thing to do would be to increase the number of footings so you could get by with a single 2x6 for the "ledger".
Alternatively, if you place the tops of the rim joists flush with the deck surface you can use 2x8s instead of 2x6s all around. This produces a more finished appearance, but requires more care with the decking.
Are you sure that 2x6 joists will be sufficient?
you gotta be kidding!
Now that we've got that out of the way, let's get constructive.
Very nice drawing. What do you do for real work?
The problem(s) are that the inside rim or ledger will indeed carry almost all the load. You do not give a couple pertinent pieces of information to base my judgement on though. One is how often you will place these pier posts. The other is how long the joists attached to the inner will be? Another question is where are you or what specifically is the live load requirement for your area? I would not build a deck with less than a 50# design and most more like 70#.
So how did you go about determining that this will pass code?
The whole inner rim joist against the house as you show it entails a lot of work to build something that would be far stronger by doing a triple and seating it atop the 4x4 post.
I like the ab44 or ab66 post anchors myself. But all your hardware should carry the new "Z" designation if you are using PT lumber. the newer treatment chemicals are far more corrosive to metal, especially in such damp environments.
You can build with deeper lumber. I just built one similar that has soil 13" below finished deck at the house and 16" at the perimeter, using 2x10. It is sloped to crain and has open air flow at sides.
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"Very nice drawing. What do you do for real work?"
His "real work" is as an illustrator for the Simpson Catalog Company. Notice the lightly tinted color on the almost hidden hoist hanger. Also The use of white on tan for the leader which ends up on one of the rim joists. But there is one overlap area.
The dead give away is the use of Simpson catalog numbers.
~Peter
It is improving but never getting better.
I've got a couple more suggestions kicking around in my head if I knew the dimensions of this thing. Might be able to eliminate the ledger altogether
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I believe the drawing gives some size information. The deck is 13 x 14 feet with a 5 x 5 foot square adjoining one corner.
He can probably run a doubled 2x6 down each long side, then a triple down the middle between them, everything sitting right down on grade with pier supports at the 1/3 points (12 piers total), then build a simple box frame of 2x6s with the joists perp to the "sleepers" below.
Each "sleeper" might fix to its pier with something like this from Simpson. Imagine no post, just the sleeper running right through the ears, bearing on the 1" standoff plate.
View Image
That is just a ballpark guess and maybe overkill on piers, but I didn't put my engineers duncecap on yet. We'll deal with the little 5x5 entryway later.
(Having paid my dues as an estimator and used to taking info off drawings, I saw what you cost-plus guys didn't. LOL!)
Edited 5/24/2004 11:04 pm ET by Bob Dylan
OK, I see it now in the lighter print after scrolling over.
No way will 2x6 joists be adequate for a deck that big!
I was thinking similar for a mount detail.
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Here is my hallucination. The 2x6s are spanning 7/0 in this version. I still didn't put on the ol' engineer's duncecap yet.
Nice drawing, Bob. What program did you use to do that?
That's just about exactly what I tried to describe in my post above, although I might have cantilevered the joists just a little.
Al Mollitor, Sharon MA
You could inset the piers and outer beams by 1-2 feet and cantilever the joists over the ends. This would hide the piers better, making the deck "float" above the ground when viewed from the sides. (In fact, the piers farthest from the house could also be inset by 1-2 feet, with the beams cantilevered as well. Then only the beam ends would show from the outside end.)
The landing would be best handled by making about 4 joists longer, with a 4th beam under the landing.
Re code: Around here this wouldn't require permits or inspection at all if the deck is no more than 18" (IIRC) above grade. It's considered a "patio".
I see that flashy has not stopped back in and I don'ty have tim enow for a drawing, but I'm thinking this way - run the carrying beams at same level as the joists, perpendicular to the house, with a cantilever across the piers to allow setting thme back from house a bit, and hang the joists to the carrying beams with hardware. The top surface then would be installed perpendicular to the house and surfacce tension would allow 80% of the water to follow it away from the house, minimizing the moisture problem under it all, and grantiung enuf elevation to use joists deep enuf to elinminate the trampoline effect.
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To ALL:
Crap, I got hacked! My 'puter, that is, shortly after reading your responses to my "false ledger" question. Luckily, and being fairly technical, I was able to solve my vicious, little computer problem by first spending a couple days trying to "catch" the stinking hacker (no luck) and "fix" his destructive ways "on my own" (again, no luck - he's a clever little twerp), then ending up simply re-formatting my harddrives and re-installing XP, downloading all the "critical updates" from Microsoft on my lightening fast 56K modem (still doing this), changing my passwords at every Website that I've needed one over the last couple years (including FHB, in case any of you have gotten some "nice" e-mails from me lately, though Piff, I actually DID send you an e-mail a while back, re: your two-PC network), re-installing all my incredibly useful software like "Duke Nukem" and "Windows Media Player", and... well, you get the picture. Pretty sure I picked up the hack (a trojan horse) from a malicious Website which is no big surprise since I frequent some strange ones (check out http://www.subserviantchicken.com when you have the chance, or more importantly, the inclination).
Anyway, what were we talking about? Ah yes, the "ledger of falseness". Well, first, THANK YOU ALL for your suggestions! (man, when I said in my original post that I was "all ears", I didn't mean that they were the size of Dumbo's <insert smiley face here>...) In the words of Gilbralter (WARNING: Obscure, probably not factual, historical reference follows) during his most famous voyage: "You ROCK!" Seriously, thanks a lot.
Will reply to your postings after my 132nd re-boot (or "restart" as MS calls it which has such a nice ring to it, kinda like "re-starting" life after giving up booze or chocolate or whatever). Oh look, I get to "re-start" again! Number 87 comin' up!
Flash
Have you concidered having you rim-joist (false ledger) be double 2x's, nailed together, sitting on top of the 4x4 and connected with a Simpson Strong-Tie BC or AC post/ column caps? The BC allows you to use a bolt to attach them in case nailling is an issue.
2 other issues are:
1. Lateral load. Since you do not have the house connection to prevent lateral movement, what will keep the deck from "folding"?
2. Placement of the peirs next to the house. The soil below is not virgin earth (back-fill) and will most likely shift once a load is placed on it. Instead, move the peirs out, away from the house and canetliever the the joists on top of the beams. This will mean your 4x4 post will be even shorter and the beams be closer to the ground, but the water disapation issue can be address be laying a tarp/ felt/ plastice sheeting on the ground and sloping it so the water flows away from the house beneath the deck.
Maybe Pro-Deck will chime in.
F
Waht Piffn said!!!
He said basicaly what i was thinking. And what are the dimensions?
You could even put more giders between the house and the outside of said deck. I would still install double or triple beams sitting on top of the 4x4s.
I would use 6x6s and notch them 3" deep and bolt the double girts through.
but thats just me.
tyke
just another day in paradise
G.E. Ely Construction
Ocracoke,NC
In these parts, if its not bolted to the house it is not a deck and will not pass inspection. It is a separate structure and has to get zoning and plan approval. Decks just have to be done to the county "standard" drawings.
Bolt it to the house. Is your mom really, really short? Or maybe very thin? She can't crawl under there. How will she ever know? That is the right way and you'll be confident it won't fall over.
As others have said, more information would be helpful.
Where are you? How deep is frost in your area? If it's not too deep and digging is easy, more piers could be used to reduce the size of the beam you need.
What's the size of the deck? That influences joist/beam size/span options. If I understand your situation, I would consider something like triple 2x8 beams sitting right on the piers (no posts, no joist hangers, no false ledgers), and the joists sitting on top of the beams with about an inch of air between the rim joist and the house. This approach has the advantage of having very little steel to worry about corroding. It's like playing with blocks: joists stacked on beams stacked on concrete.
Keep it simple, stupid! (That's the royal 'stupid.' Nothing personal.)
Al Mollitor, Sharon MA
Like Al said, there may be an advantage to a cantilever on the house end, so that you do not need to dig for posts very near to the foundation.
Tell your Mom it is for her own safety that the ledger be fastened to the wall. Save yourself a ton of grief. Cut flash and drive some new Fastenmaster Ledger board fasteners approved for ACQ into the rim of the house.
Now Fess up! What is the 3D program use are using for your drawings?
"Rather be a hammer than a nail"
Bob
He's taking that secret with him to that great electron in the sky
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