On Saturday night a deck collapsed killing one person.
A couple had built a new two story home with a two story deck and they were having a large party.
A lot of people were on both decks when it collapsed.
Last night on the news they interviewed a guy who was present at the party.
He said the deck pulled away from the house and then crashed down on the people below.
I’m guessing the ledger board pulled away from the wall.
What’s the proper way to attach the ledger board to the wall?
Use lag screws rather than nails?
http://www.wichitaeagle.com/news/
^^^^^^
a Smith & Wesson beats four Aces
Replies
Lag screws at the very, very least--and in most places that is not to code--you should be through-bolting the ledger with the proper bolts at the proper spacing (according to code or ask your building inspector). If you nail the ledger, the type of accident you describe can happen.
This was a brand new home. It was a second home - vacation home and the owners are well to do.The victim and injured will sue the homeowner, the contractor, and the home inspector.Maybe even sue the code enforcement official who gave the final okay on the home (certificate of occupancy).^^^^^^
a Smith & Wesson beats four Aces
Wow. I can see where that might be something that'd get by an inspector, but the builder should have known better. Nails are poor in withdrawal and that is what apparently happened--if all the people had been standing right near the ledger, the force would have been downward, trying to shear off the nails, but if they were out further on the deck, the deck wanted to pull away from the house and just pulled all the nails out. (That's my guess, not having seen it.)
Maybe they installed the ledger with a nail gun. Pling Pling Pling It's done in seconds (as opposed to spending an hour drilling holes and using a socket wrench to install lag bolts, etc)^^^^^^
a Smith & Wesson beats four Aces
Last one I did I used 5/8" bolts through the rim joist every 12", staggered. Inspector was impressed, but I thought that was what it needed. Bear
"Pling Pling Pling It's done in seconds (as opposed to spending an hour drilling holes and using a socket wrench to install lag bolts, etc)"
this is where having the right tool makes all the difference. drilling the holes with a good drill and sharp bit takes little time. Now this where you keep your socket wrench in the truck, unplug your gun and plug in the impact wrench - the process will not be seconds like the gun, but you are definitely in the "minutes" and not long category.
Impact wrenches pay for themselves usually on the very 1st job they are used on. plus you can use em at home when changing your tire. those who have med to large compressors and no impact wrench, should think about getting one. and pick up a tire chuck while you are at it.
EDIT: if you have a med vs large compressor set your bolts as you go after drilling each hole vs setting all the bolts at once. you will tax the compressor for air otherwise. Same if you have a larger compressor but other crew members are feeding off it for their guns - you will get dirty looks and get called an "air hog". other option is the electric impact wrech is is a great tool. some of the cordless impacts can even handle bolts up to a certain size these days.
Edited 5/7/2007 10:00 am ET by alrightythen
This sounds like a ledger attachment problem and it might be interesting to know which ledger failed first. There will also be a great deal of discussion about the number of people on the deck(s).
The homeowner and contractor are probably in for a pretty rough time, but the inspectors and code enforcement people are probably in the clear. Most building departments, inspectors, etc are immune from liability.
I'm kinda fond of the deck being reasonably self-supporting, with posts near the house and the ledger attachment mainly for stability.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I agree--support independent from the house seems best.
The problem is that digging footings right up next to the house is often a PITA. For example, if there is a full basement 6' below grade, since all that dirt next to the foundation is fill, that pretty much means that you have to dig 6' deep footings. I'll watch you do that - OK :-)
Other problems occur too - Like inboard deck posts often end up 1/2 on and 1/2 off the house footings meaning that the new footings either need to be poured rather thick or pinned to the house footings... or like on higher decks, the need for more diagonal bracing since the house is not providing lateral stability, etc.
The only real advantage is less chance of water intrusion - granted that is big advantage but I'm just not sure it's worth up to $1k extra in time and materials.
Edited 5/10/2007 7:31 am ET by Matt
They don't have to be right next to the house. 2-3 feet from the house is fine. Deck support posts do not need to be at the corners of the deck, contrary to the apparently common misconception.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
i think setting the posts back & using a girder (?) like you say makes for a more attractive deck and easier to build (ie, the posts don't have to be exactly the right location (for a corner))
>> 2-3 feet <<
So, you are saying that a 3' cantilever is OK??? Here it isn't. Either way though, in the case of a somewhat deep basement, although the basement footer would not be in the way, that area would have more likely than not been excavated for the basement construction meaning that virgin ground would only be available fairly close to basement footer depth.
Edited 5/12/2007 8:52 pm ET by Matt
Cantilever is simply a matter of physics. There is no limit (though obviously there are "rules of thumb" for "standard construction").In any event, the load is split between posts and ledger. Belt and suspenders.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
no limit?!You live under different laws of physics than most of the world
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
OK, there is a limit, but it's probably about a half a mile. And if we ever figured out spider web material we could better that.Look at the new Grand Canyon observation platform, eg.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Piffin,
Are you trying to be facetious?
Technically, there may not be "NO" limit but reasonable people realize what Dans claim implies.
http://www.petedraganic.com/
No not facetious at all.Just making a point. Unless you do away with gravity and the forces it exerts, there is a very real and practical limit to how far one can cantilever.The standard codes allow only up to two feet with restrictions. there are certainly extreme upgrades and enmgineered designs that can take you further, but even then, a cantilaevered structure must by definition be less than it's back board end.I do make attempt top design my decks free of the building when possible. Agree with you in that.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
there is a very real and practical limit to how far one can cantilever.
Here is the new Institute of Contemporary Art in Boston.
View Image
With enough money, engineers and steel, who knows what the limit is. Plus, if it falls into the harbor, it will float!
Why do they make such ugly buildings for art?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Why do they make such ugly buildings for art?
Now, now, we don't want people thinking Mainers are a bunch of Philistines. Frankly, I think it is a spectacular building.
It is awsome from an engineering perspective!So is Dolly Parton, but there is also some degree of art in her makeupBut it'll be a dangerous day when her deck collapses
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It is awsome from an engineering perspective!
So is Dolly Parton, but there is also some degree of art in her makeup.
But it'll be a dangerous day when her deck collapses.
Perhaps you should volunteer to inspect the structural underpinnings. Don't forget the safety glasses.
I'm sure it'll still float too!;)
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
But I wouldn't mind being under her when it does!
Maybe the building is that way so you'll be relieved when you get inside and see the works of art (although nowadays that may not be the case--might have a crucifix in urine as art work!).
Very much similar to the new Guthrie Theatre in Minneapolis.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
>> Cantilever is simply a matter of physics. There is no limit (though obviously there are "rules of thumb" for "standard construction"). <<
Here code does not allow a cantilever over 2' and any cantilevered deck requires a minimum of 2x10 joists. One could probably get either of those overridden by an engineer, but now you have not only added construction expense but planning expense. Is there a code requirement for cantilevers in your state?
>> In any event, the load is split between posts and ledger. Belt and suspenders. <<
OK - I'll buy that, except if you have a ledger board supplying structural support, as far as I'm concerned, you have just lost the major advantage to having the drop girder with posts up next to the house - namely, elimination of the ledger so that you have no chance for water intrusion at the ledger...
IMO - here is the bottom line:
1) A free standing deck with no ledger (band joist) attached to the house is structurally the most sound way to build a deck provided that appropriate lateral support is provided.
2) Often, installing a drop girder up next to the house is significantly less feasible than attaching a structural ledger board (band joist) to the house for several reasons.
3) A ledger board (band joist) that is attached to a house and supporting a deck must be through bolted to the house framing and well detailed (flashed) to prevent water intrusion. The through bolting is my preference and my state's code requirement. Many state codes accept lag screws.
I an supprised that you are limited 2ft cantilever.He is the Fairfax VA deck details. If you use those you don't need any designs or engineering.They allow 3 ft cantilever over the joists.But only 2 ft over the beam from the post.http://www.fairfaxcounty.gov/dpwes/publications/decks/details.pdf.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
That's a nice document. Looks to me like they are going out of their way to provide some good guidance.
Yeah, our deck plans were fully pre-checked by the local BI office (and they do non-trivial checks -- instructed us to beef up a couple of beams). We've got three separate 3-foot cantilevers, with 8" joists -- didn't bother them at all.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Dan, This thread about cantilevers has me amused. I once did a roof cantilever using mono trusses, 12' cant out over a deck with only 8' inside the building line. It is all in the engineering.
"Poor is not the person who has too little, but the person who craves more."...Seneca
Yeah, there's certainly no physical principle that says a cantilever can't go beyond so many feet, until you get up to the point of absolute limits of strength of materials (which would be on the order of miles, I suspect).Where you see problems is mostly with cantilevered balconies where the balcony joists were not run deep enough back into the supporting structure. Easily 10 times as many decks fail due to ledger board failure than due to cantilever failure. (In fact, don't ever recall hearing of a cantilever failure on a deck, but several ledger failures make the news every summer.)
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
DanH,
I have had to replace cantilevered deck structures with ledger and posts structure.
The problem was not in the strength cant itself , rather in the flashing of the cant joists.
Joists started to rot just inside the wall line.
"Poor is not the person who has too little, but the person who craves more."...Seneca
But you're talking about cantilevers off the house, not off the deck structure. One of the things a cantilever off the deck can avoid is flashing problems at the deck-house connection. (Though, really, just about any scheme should be able to be adequately flashed.)
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Some friends of ours in Chatsworth have a deck that's cantilevered about 12 feet. Its beams are steel, and structurally sound, but they're considering putting some posts in to get rid of the uncomfortable bounce.
-- J.S.
I am trying to figure out how to cantilever three feet OVER the joist. I can picture a joist cantilevered three feet over a beam....
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I suspect he was talking about the two cases of a) the beam is supported some distance from its end, and it supports the ends of the joists, and b) the joists are supported some distance from their ends. Though I couldn't quite figure out which was which from his comments.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
"I am trying to figure out how to cantilever three feet OVER the joist. I can picture a joist cantilevered three feet over a beam...."Actually it is called a Diving Board.But yes, what I really ment was the joist cantilevered 3 ft over the beam..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Dan... Thank you! I see so many of these Q's about decks and I feel like I am screming into the wind when I repeatedly preach that decks should be free-standing.
It's good to know I have someone on my side... finally.
http://www.petedraganic.com/
Checked a fence yesterday i'd put up last summer. One of the 2x4 pt top rails had warped over the winter. The twisting action pulled it out from a post, and it had (4) 3" galvanized nails pulled up with it.
Can't imagine someone putting in something like a ledger with just nails.
Paper said there were 85 to 100 people at the party.
Ozlander
I wouldn't blame just the ledger attachment -- I would think a proper deck design normally shouldn't apply forces which would pull the ledger out. The ledger should be firmly attached as a redundant safety feature, not primary.
If the design requires pullout strength on the part of the ledger, then someone really dropped the ball on either specifications or installation.
Don
You saved we the need to say the same thing. This is hardly a result of the ledger. I would say overall design and excessive loading were the primary culprits. Many munincipaities require decks to be free standing. A deck needs to be designed with the necessary support to prevent racking of the frame. If a free standing deck shouldn't rack neither should one attached to the house.
In reality, pullout and shear don't exist as separate isolated things. Nail two pieces of wood together and load them in shear. What happens is that the wood next to the nails gets just a tiny bit crushed, which allows the nails to start to bend into a very gentle "S" shape. Apply more load, you get more crushing and more bending, and part of the shear load gets converted into pullout. A gap forms between the pieces of wood, giving the nails more room to bend. You get more pullout as the joint gets weaker and fails.
Now is the time of year when decks that have been ignored all winter suddenly see huge loads. TV news could save some lives by pointing out the wisdom of inspecting your deck before you throw a big party. We're going to see a lot more of this as decks built with corrosive ACQ get older. ACQ collapses will probably kill far more people than CCA ever did.
-- J.S.
Edited 5/7/2007 3:45 pm ET by JohnSprungX
I'm no engineer, but I expect you'll be seeing alot more of this in the future with the use of truss joists and engineered I joists. First there seems to be little concern on the fasteners used to attach them to the acq mudsil. Second some I joists use a 1" thick osb rim that require a specific lag attachment of the ledgerboard.
I personally was on a job that had a very nice looking deck built by an unlicensed, uninsured contractor with no permit. He had access to the interior but opted to lag the ledger through the osb rim 2' oc in a straight line. He commented on how the impact wrench spun "some" of the lags. Wouldn't catch me partying on that deck.
>> I wouldn't blame just the ledger attachment -- I would think a proper deck design normally shouldn't apply forces which would pull the ledger out. The ledger should be firmly attached as a redundant safety feature, not primary. <<
Not meaning to be rude here, but that is a good theory but doesn't have much to do with reality. I'd guess that 80 to 90% of the decks built in the US use a ledger board (rim joist) to transfer approximately 50% of the deck load to the house structure, foundation, and footings. Some areas may require free standing decks, and in some situations they are implemented for other reasons, but the above statement is basically saying that 80 to 90% of decks in the US are build wrong from a structural standpoint. Sorry. I can't buy it. Load bearing ledger boards work fine as long as long as they are fastened and flashed properly. Some people don't like them because of the possibility of water intrusion, but that isn't necessarily a structural design issue.
If one follows this issue of deck failure much, they would know that ledger attachment is responsible for a significant percentage of deck failures.
Have you seen these LegerLoks from FastenMaster?http://www.fastenmaster.com/I've used them for some other applications, they are pretty awesome for screws.While I know it's not always possible, we do our dangedest to make our deck banding part of the house banding system.
Outside of the gates the trucks were unloadin',
The weather was hot, a-nearly 90 degrees.
The man standin' next to me, his head was exploding,
Well, I was prayin' the pieces wouldn't fall on me.
I have not seen these before. I probably would allow these ledgerlok screws to substitute for the 12d nails but not the 5/8" bolts. I am not willing to shoulder the responsibility for a potential failure of the connection.
Not sure I'd want that reponsibility either...I'll check their documentation, and see what our local guys say. Outside of the gates the trucks were unloadin',
The weather was hot, a-nearly 90 degrees.
The man standin' next to me, his head was exploding,
Well, I was prayin' the pieces wouldn't fall on me.
My point wasn't that you can't or shouldn't use a ledger, but that a ledger normally is laid out to accept primarily shear loads. If it's subject to a pullout load, that implies to me that some other part of the deck has already failed to some extent, leading to unplanned forces on the ledger.
On the other hand, in post #15 in this thread, J.S. outlines the potential for pullout forces due to failures in the shear strength of the ledger attachment, which obviously would be a result of poor fastening methods or overloading.
I'm not saying that redundant means unnecessary - good builders & designers always try to build in redundant supports in key structural components -- all very nice to have when a tree falls on the structure, or the kid learning to drive takes out a support post.
Don
OK - I guess I misinterpreted your initial statement. You are right: The forces on the ledger, and more specifically the fasteners should be sheer. Like I said earlier though, here, we are required to through-bolt which means shear and pullout are dealt with.
But I still don't understand what your driving at with this >> redundant support << with respect to deck ledgers. And the >> The ledger should be firmly attached as a redundant safety feature, not primary.<< To me that sounds like a beam & posts right up next to the house - ie a free standing deck - but I guess that is not what you mean. Please be specific about this redundant support. What do you mean? If the ledger and fasteners is not the primary means of support for the 'inboard' side of the deck, what is?
I should have been more specific - when I said "firmly attached", I was referring to thru-bolting, or at a minimum serious lag bolting -- as compared to nailing.
Basically, if you're just nailing, then you're pretty much assuming that you won't see any pullout forces (or don't realize that nails are pretty much worthless for such). Nailing, if done correctly, should be able to handle the shear loads.
Thru-bolting is an acknowledgement that in real life pullout forces can happen, therefore allowing for such provides some redundancy.
Don
OK - gotcha...
Last summer I repaired four decks with hot tubs that had failed. In each case the built-up wood beam has rotted and sheared off at the post. The worst of the decks, which alerted the owner to the problem, dropped about a foot and was left supported by the joist hangers attached to the ledger. I emptied the tub, jacked up the deck and replaced the beam.
My experience agrees with your take on deck ledgers. Their method of attachment is not going to be the primary reason for collapse. However, once something else goes wrong, it is nice to have a good connection to fall back on.
I must admit having watched first the amazingly over detailed solutions with doubled ledgers and spacers that were published in FHB as a response to water penetration at decks, I can't help but think that we may be similarly over-thinking the ledger's structural connection right now. Sure, deal with the ledger, but worrying about the other connections at posts and joists is important too.
A similar thing happened just this weekend in San Francisco. A new owner was performing work under his home and the whole structure fell off the foundation. The news article did not detail what went wrong except to say the homeowner making some changes to the foundation himself when the collapse took place. He was uninjured but fire was called to rescue his dog inside. The home, only three weeks after he purchased it from the prior owner, was "red tagged" immediately. What a bummer, I'll bet the homeowners insurance isn't going to back him on this one since he was unqualified to do the work and he's still on the hook for the home loan.
Last night's news also said that the owner had been given 48 hours to come up with a demolition plan. When the house collapsed into the basement, it also leaned onto a neighbors house.
Some homeowners scare me half to death. Last week, I walked away from what could have been a very good project. The HO wants to replace the patio doors and windows in his $1.5M house. When I started talking about building temporary walls to carry the loads while the old walls were demo'ed and rebuilt, he said that he didn't think that would really be needed. That's when I shook his hand, wished him good luck with his project, and left the building!! - lol
I don't believe any fastened attachment should rely on engineered rimboard type products. I predrilled and lagged top and bottom into each i-joist at 16" o.c. with 3/8" lags. Those pairs of lags pick up a tributary width of over 9 square feet for my deck. I think 60 psf is not overly conservative for a deck live load. Drifting/sliding snow along that ledger could be 100 psf. With pt joists and trex that pair of lags picks up over 1000 lbs of static loading. That means my lags are under-designed for sliding snow load...and how many decks have that many fasteners?
Tuolimne-
You may be using many more fastners then normal but lagging into endgrain finger joined 2x3 material may not be recommended by the mfg therefore negating your best efforts to overbuild and make a structure secure. This is what I believe will lead to an influx in deck failures. You may have the best intentions in the world, but if a deck comes down and you didn't follow the instructions provided by people that went to lots of years of college to provide... What you thought would be fine ain't gonna be worth a spit.
That is so sad.
Once upon a time I was at a convention where one of the "events" was a party for friends, friends of friends and hangers-on of the executive committee. I slipped out of the hot room on to the balcony and found elbow to elbow people out there. Even drunk as I was it didn't seem right. I slipped back into the room and left. Luckily the guys who built the hotel made that balcony strong enough to hold the weight of a bunch of fat-butt programmers.
I don't know what the code is on this sort of thing but if I were ever to build a deck it would have to be strong enough to hold up to it being crowded with fat assed people jumping up and down to some music. Not just 4 people sitting quietly sipping tea. Just like you would design a house to stand up to a hurricane. Not just a gentle summers breeze.
i remember in college a structures professor using a similar analogy. Can't recall the exact situation, but it was after the Kansas City balcony collapse. Another building in town had a similar loading condition. He said the engineers calculated the maximum # of people, all of them doing the Bunny Hop.All of those potential people landing at the same time makes a helluva larger load than when they're simply standing around talking. Codes aren't a replacement for forethought and common sense.
I would be surprised if this deck was in compliance with the building code. The codes usually have a large safety factor built into them.
The Kansas City balcony collapse was caused by a load that was well under that required by the building code even factoring in any possible increase caused by dancing in synchrony. The collapse resulted from a change in the rods than held up the balconies, a change made for the convenience of construction and approved by the supervising engineers. This change no longer met the building code requirements.
What happened in the KC collapse is that the original design had both levels attached to the same continuous rods from overhead. Sort of like two guys climbing the same rope.
The re-design had the rods cut so that the lower level rods were attached to the upper level, and the upper level was attached to the top rods. Sort of like the bottom guy grabbing the top guy's ankles instead of the rope.
This doubled the load on the connection between the top level and the upper rods. Unfortunately, nobody thought it through carefully enough to catch that. If they had, the upper level could have been beefed up to handle the actual load, and we never would have heard of all this.
-- J.S.
I've read up on that failure, too. I think the book I had was "To Engineer is Human".
The guys in the field should not have made the revision they did; however, I also feel like the design was not very buildable. It's almost like the engineer that did the design did not give much thought to how it would go together the field. (Like that never happens. . . )
Terrible tragedy on that deck. I am building mine now. I agree that the new PT will be causing some big failures in about 5 years.
For my deck, here is what I did (you'll laugh at the screw part of it) .
I started out by putting 1/2" SS carriage bolts backed up by 2x6 lumber cutoffs through the SIP RIM board. The ledger is dropped 6 inches below the FF deck, so the bottom 1/3 is roughly over the concrete of the foundation.
I did not want the ledger to warp away (as PT likes to do), so I then went back and threw some 3" SS screws every 16" or so through the Ledger and into the treated Sill.
Then I thought that the screws were kind of cheezy, so I went back and put in some 1/2" SS lags into the sill, too.
So I have cariiage bolts along the top 1/3rd and screws and lags about 2/3rds down.
I've finally started on the deck (I did the ledger in the fall) and I've noticed the ledger has shrunk enough (dried out) that some of the lags are actually loose now! I'll be re-tightening tonight.
Also, because I did not go with SS hangers (although I did get the Triple-Z, or whatever they say is OK for the new PT) I have isolated the first 2" of the joist from the wood and the hanger from the ledger with strips of tar paper. It might be argued that I'm trapping moisure against the wood with this, but it is my hope that tar paper will exhibit it's usual fast-drying tendencies and that won't be an issue. I suppose the weak point now is the HDG nails. . . .
http://jhausch.blogspot.comAdventures in Home BuildingAn online journal covering the preparation and construction of our new home.
Ah yes, the Hyatt collapse. My garandparents were supposed to go to that party but changed their plans, thankfully.
As I understand it, the inspection on that building took 45 min. And people wonder why I don't have much respect for KC building inspectors.
It is fun to ask them if they were the inspector on the Hyatt.
bump
Building codes vary from state to state. In NC a deck ledger is required to be through bolted to the house rim board with 5/8" HD gal bolds, nuts & washers. In addition HD gal nails are required. The bolting and nailing schedule depends on the width of the deck.
Lag screws pull out and nails are not enough.
Always bolt your non-free standing deck bands to the structure, in NC we adhere to the following code guidelines:
Ref. North Carolina Residential building code Appendix "M"...
All structures excepts Brick Veneer Structures:
1 @ 3'-6"o.c.
*Min. edge distance for bolts is 2-1/2"
** Nails must penetrate the supporting structure band a minimum of 1-1/2"
Brick Veneer Structures:
* Min. edge distance for bolts is 2-1/2"
Also decks shall be laterally stable. meaning adding "X" bracing or 45 deg. knee braces both of which must be bolted to the post with one 5/8" Hot dipped Galv. bolt on both ends of the brace. The lateral stability can be accomplished by other means such as deep post embedment in the earth.
I guess deck attachment to the ~1" rim board of an I-joist floor system is subject to mfg recommendations - GP, LP or whatever? If so do you know what the requirements are? Anyone?
And, BTW - have you heard anything about when we get the new 1 and 2 family residential code books? Are they still saying June? That's not far away...
And another Q... Sorry... I'm doing some planning for a town house project. What differences are in code requirements for town houses as compared to single family residential construction? The only thing I know about right now is the requirement for a fire wall between units. I see local contractors are using multiple sheets of Dense Glass assembled in metal channels between the studded walls of 2 adjoining units. Or, if it is too much stuff, how about some pointers to some code sections to read?
Q#1 You are right refer to mfg. specs for attachment to ~1" Rim boards, if you can get them. To my knowledge the Rim boards are rated for vertical load only and do not provide any horizontal resistance. I have repeatedly failed builders for attempting to attach a 2"x2" ledger to a ~1" rim and support floor joists. I have done this and requested Manufacturing attachment instructions..to this date no manufacture will supply a detail so I am pretty sure attaching deck bands are out of the question without supplemental engineering.
Q#2 As of last week, 5/2 at an inspector meeting everything was still on go for June '07 for the new Residential code. But we have heard that before.... Full implementation would be in Jan '08.
Q#3 To much information for this format except, Townhouses are completely commercial and must be engineered including the UL rated fire walls. Hire an engineer or architect and refer to NC Building code chapters 3,4,5, 6, 7, 9, & 10 along with UL standards. All the code chapters deal with separation, types of construction, and egress requirements for R-2 construction.
Re my 3rd Q, to date, all my companies commercial projects have been designed by architects and engineers to date, however on this town house project we are considering using a designer and then an engineer. BTW - here, anything bigger than say a deck or porch needs an engineer's stamp.
I've written down the chapter numbers and will start on it tomorrow. I have much more experience on residential projects, but have done some commercial work too. In the past I've found the commercial "Building Code" book a lot less user friendly than the residential bode book. At this point we are in the pre-design stage, and I'm doing some feasibility and financial analyses type work.
Kinda funny. The inspector in the town I do alot of work in doesnt allow ledgers. Last deck I built there he said he wanted joists hangers and that was it, no ledger.
A few years back, the local university head, while entertaining internation dignitaries at her lakefront cottage, had it collapse. I don't remember the details, but I know the canadian building code changed the next month. Insurance companies definately control the building codes here in canada!
BTW. I threw bolt! 5/8 threaded rod.
Mrfixit
I wonder how many of these collapsed decks we are going to see in the not to distant future.
I have an aquantance that builds to the cheapest possible standards that he can. Plain and simple, he just doesnt know any better.
He will build a deck using the new treated wood and fasten it all together with electro-plated deck screws! Hell those things rust in the old style treated wood. I'm guessing he doesnt do much more then screw the ledger to the house.
All of the work that he does is without permit so unless someone, neighbor, passer by .........anyone, calls and reports it the job goes on. Kinda scary!
I've talked to him about the dangers of what he does but he's limited mentally so it falls on deaf ears.
I'm usually not to much a stickler for things like this but if I went to a party/function and the deck was up high I think I might go undernieth it and give it a once over, peace of mind and all.
Doug
Doug,
All of the work that he does is without permit so unless someone, neighbor, passer by .........anyone, calls and reports it the job goes on. Kinda scary!
I've talked to him about the dangers of what he does but he's limited mentally so it falls on deaf ears.
And aren't you a "passerby"? Why don't you make the call??
If you truly believe there are dangers in what he's doing and he is in fact "limited mentaly" don't you have an obligation legally and morally to prevent a potential disaster?
We as a group, work hard to professionalize our industry and improve it's image. Knowingly allowing someone who is doing not only sub-par work, but work that you yourself think could cause harm down the road is not helping that image problem!!
Make the call!!
I'm usually not to much a stickler for things like this but if I went to a party/function and the deck was up high I think I might go undernieth it and give it a once over, peace of mind and all.
Not too much of a stickler for what? permits?, good building practice? ledger attachment details? After reading your posts on the built-ins, you cut no slack to the cabinet maker on his lousy joinery and questionable finishing, why not hold this guy to the same high standards, and yourself as well, make the call!
Geoff
Geoff
All your points are valid. I do help him to re-do things when I can but I have a job and cant babysit the guy, besides the people that are using him because he's so much cheaper then anybody else have some culpability in this to.
I've gone over to a number of jobs with him to help him get it right but I assume some liability by just being there and I'm only willing to do so much.
I've helped him tear out joist hangers and by using ice and water shield we at least isolate the galvanized piece from the treated wood.
I've taught him to quit using the crumby screws that he uses but you really would have to spend a little time with the guy to get what I'm talking about - he draws social security because his IQ is considered "to low".
How much will he learn from what I help him do - don't know but I do try to help him.
I could turn the job into the city but I'm not there for every job he does so then what?
Not too much of a stickler for what? permits?,
Your on the attack but don't over reach here. I never said anything about not getting permits so don't go assuming anything that isn't there.
What I meant(and probably didn't articulate it well, obviously that's a problem of mine!) is that I don't normally go looking at the construction of a deck before going out onto it but if they are high up I may make an exception to that practice.
Heres an example of how this guy thinks; I bought a used topper shell for my truck-wrong color. I need to paint it and I really don't want to do it so I mentioned it to him that I was looking around. He called me up yesterday and said that he knew a guy that would do it for $100!
Hell the paint for this is about $50-$60. So that means the guy will mask off, sand and apply several coats of red paint with a final clear coat over that, all for $40-50 bucks! I ask him if he sees any thing wrong with the guys price, his answer, "no" and he really don't, that's the problem. He really don't get it. And for those people that are looking for the very bottom of the barrel bid - well, he's their man. They have to assume some liability in all this as well.
ledger attachment details?
I used to do trim work for the local trac-home builder, occasionally we would build the deck on these places. It was up to the project manager to locate the ledger board so that the siding guys would side around where it attached. All we were supposed to do was bolt/lag our ledger board to the building, the flashing was to be installed by the siding crew.
One project manager had a real problem locating these, that and getting off his azz to do his job.
He would have the siding guys just go ahead and side the whole house and then tell us to place the ledger board right over the siding and lag it to the house! He claimed this would be better because there would be no way for water to get behind the siding-therefore he convinced himself that his lazy azzed way was better.
I refused to do it. He would then give the job to one of the other trim crews. They had no problem with it and the city inspector never caught it, or at least didn't see a problem with it - and I did point that out to them but........
Doug
Edited 5/8/2007 11:23 pm ET by DougU
I find that bolting the ledger on is the best way but not always possible.
I usually go 2 on the ends and one between every joist space using 3/8" or 1/2" (depending on required strength). So basicly every 16" and alternating upper part of the ledger and then the lower part of the ledger, ....and so on.
Dave
To allI think that people are using ledger in this thread to mean too different things.1. A "rim joist" that is attached to the house. The deck joist or then connect to the rim joist by one of several means. The most common using current practices is joist hangers. This is commonly called a ledger board.2. A strip of wood that is attached to a rim joist or support beam and the joist are set on top of it. Or the joist or notched and the notch sets on this strip.Ledger boards of the first meaning are commonly used on decks.There is the recommended detial on deck building from Fairfax Co Va and I think that they would be acceptacle in most areas.http://www.fairfaxcounty.gov/dpwes/publications/decks/details.pdfIt uses a ledger boards, of the first meaning, attached to the house using lagbolts. But that depends on the specific construciton of the house..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Good point on the terminology. I try to stick with "ledger strip" to refer to a joist supporting 2x2 (or whatever) and "ledger" to mean the rim joist.
Still though, it seems that, at least in my area, code changes are phasing out the use of ledger strips.
>>I find that bolting the ledger on is the best way but not always possible. << and >> I usually go 2 on the ends and one between every joist space using 3/8" or 1/2" (depending on required strength).<<
First, I assume you mean through bolts, nuts and washers as opposed to what some people refer to as "lag bolts" which I call "lag screws"?
Secondly, when is it not possible to through bolt? I can think of a few scenarios in which it would be difficult in which case I'd either find a way to bolt it, or make it a free standing deck.
Also, IMO 3/8" bolts are sub par. Not only because of the strength of the fastener, but also because of the lack of area of wood the washers cover on the ledger board and house rim board. And even 1/2" could be inadequate in some situations, ie 8' tall, big deck.... We use 5/8" per code, in which case they are sometimes overkill, but I never have to look back over my sholder on that one...
OK - maybe you could be using fender washers? Although I've never seen HD Gal Fender washers, I guess you could probably special order them... Or, maybe SS fender washers insinuation SS bolts too but aren't SS bolts somewhat weaker than regular steel bolts? Not sure - just asking. After all that though it would be easier, just to go with a larger size bolt?
View Image
Edited 5/8/2007 12:21 pm ET by Buttkickski
darn good drawing if the deck were four inches lower!
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Good catch, Piffin! Especially in our climate, you'd never want a deck lying higher than the adjacent finished floor level. Four inches lower than what was drawn would be a very good idea. Still plenty of meat on the rim/band joist to bolt the ledger to, but low enough to keep snow melt from challenging the door flashing.
Buttkiski,
Now that is how I used to then when doing second story decks, although I had one additional piece. We placed blocking behind the band joist between the floor joists and nailed it in place before we decked the floor. In essence doubling the rim or band. Gave us an additional layer of pull out protection.
"Poor is not the person who has too little, but the person who craves more."...Seneca
You might notice that the house was connected to the deck also yet the house did not fall down - the house was designed better than the deck.
There is no need to use bolts to fasten the deck to the house, nails do just fine.
The problem is that people do not design the deck properly and then expect the nails to compensate for the poor design.
There is no need to use bolts to fasten the deck to the house, nails do just fine.
The problem is that people do not design the deck properly and then expect the nails to compensate for the poor design.
Could you elaborate on this? What do you consider a "good" design?
If this is the case, that it's poor design, why hasn't the code addressed this?
Geoff
He barely has the brains to successfully blow his nose, and appears to have no practical construction experience. It's best to just ignore him.
Genius is 1% inspiration and 99% perspiration.
The code is not a design guide. The code is simply a prescription that if followed must be accepted by the AHJ.All the work I do, I engineer and inspect. If you are concerned about deck failure, hire an engineer, express your concerns, follow his plans.
"You might notice that the house was connected to the deck also, yet the house did not fall down - the house was designed better than the deck."
Does that mean it met code(the house)?
So, like I asked, What do you consider a good deck design?
"The code is not a design guide."
The code is a design guide, you can't use certain design methods because they don't meet code, such as is illustrated above, the house didn't fall down, better design or met code or both?
Geoff
I have seen you make some goofy posts here before but this one takes the cake. Are you trying to get somebody killed?
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Since you are not an engineer, your comments are less than helpful.
snork*
tagline- The secretary of the Province of New Netherland, writing in Dutch, in 1650, for the information of those who wished to take up land there, states more particularly that "those in New Netherland, and especially in New England, who have no means to build farmhouses at first according to their wishes, dig a square pit in the ground, cellar fashion, six or seven feet deep, as long and as broad as they think proper, case the earth inside with wood all round the wall, and line the wood with the bark of trees or something else to prevent the caving in of the earth; floor this cellar with plank, and wainscot it overhead for a ceiling, raise a roof of spars clear up, and cover the spars with bark or green sods, so that they can live dry and warm in these houses with their entire families for two, three, and four years -Thoreau's Walden
Edited 5/13/2007 9:37 am ET by rez
yes, Allah!
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There was a follow up on it today, and it said there ARE no inspections or code enforcement in that county: http://www.kansas.com/228/story/64521.html
the pictures on tv showed a really nice clean ledger laying on the gound,didn't see any bolt holes or lags sticking out. it appeared to be a very large deck,i'm guessing 30 foot long by 16 out from house. if i heard right the man that was killed was sitting under it when it collasped along with a dozen other people. just so you don't think kansas is unregulated i'm real familer with the town this is in. population is probably 300 people,no grocery store or anything,let alone a city hall etc.
it's not surprissing that the owners had no comment to the media,they just lost a friend and probably relize that someone is going to sue. larry
hand me the chainsaw, i need to trim the casing just a hair.
http://www.strongtie.com/safedeck/
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Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
The contractor who did the deck at my ski place just nailed the ledger on.
A second story deck...
With a hot tub on it...
In earthquake country...
Oh, and my builder missed it. I was more than a bit displeased about it.
I know that's a lot of weight putting a hot tub on the balcony.I remember something that happened 40+ years ago when I was a kid. We went to a family reunion at grandma's house which was an old, small house.My dad had 12 brothers and sisters and they were all there with their kids and the house was full of people.The kitchen was completely full of people and they were in there fixing their plate of food. It was summer time and we sat outside on picnic tables to eat.The old house couldn't handle all the weight.The floor sunk down a couple of inches in the middle of the room. There was no basement.I'm guessing some of the floor joists just snapped. ^^^^^^
a Smith & Wesson beats four Aces
I feel like I say this until I am blue in the face and NOBODY seems to listen......
DO NOT ATTACH DECKS TO HOUSES. A proper deck should be a free-standing structure!!!!!!
Sheesh!
http://www.petedraganic.com/
Are you saying a deck should not be attached to a house?tagline- The secretary of the Province of New Netherland, writing in Dutch, in 1650, for the information of those who wished to take up land there, states more particularly that "those in New Netherland, and especially in New England, who have no means to build farmhouses at first according to their wishes, dig a square pit in the ground, cellar fashion, six or seven feet deep, as long and as broad as they think proper, case the earth inside with wood all round the wall, and line the wood with the bark of trees or something else to prevent the caving in of the earth; floor this cellar with plank, and wainscot it overhead for a ceiling, raise a roof of spars clear up, and cover the spars with bark or green sods, so that they can live dry and warm in these houses with their entire families for two, three, and four years -Thoreau's Walden
Who's gonna trust a guy with a blue face anyway?
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More issues are sure to come. I was amazed today- needed a small piece of copper flashing for the ledger board on a deck. Went into the local store and only saw about 10 feet on the shelf taken up with alumium flashing. I pointed out to the clerk that aluminium shouldn;t be used with the new pressure treated stuff. He stated that he could get copper in a couple of days but none of the contractors wanted to pay the difference. Pay me now or pay me later.
I wasn't aware that copper was suitable either.
http://www.petedraganic.com/
'tis
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I thought everyone might like to see another scary deck - unfortunately this one is on my house. It is hard to imagine it is still hanging in there since it was constructed in 1982, although it is a small deck and rarely used. It is hard to see, but the bottom half of the joist hangars hang off into the air.
I plan to re-side the house later this year and will rebuild the deck with proper attachment to the house this time. In the meantime, the deck is off limits to anyone. I also have a much larger deck which is also attached in the same way, but at least it is only two feet off the ground so that is not too far to fall. I will re-do that one as well.
Wow, that's pretty crazy.