If I was just the framer I'd just follow the damn plan...




but I ain't...

 

Confirm w/ bldg dept your proposed plan changes - then

Joists back to mudsill, sistered to cantilevered house joists.
Full-height blocking between joists at outside edge of cantilever.
Subfloor edges get nailed to blocking.
2x3" L-flashing above blocking line on outside of house wall framing will help kick water away from joist/blocking connection.

Be sure joists can handle new, longer span (back to mudsill).

Mac

 

Install inverted hangers on the rim of the cantilever and attach as normal.

 

http://www.strongtie.com/products/connectors/DTT2.asp

I'd feel better using these and following the print

http://www.google.com/imgres?imgurl...cid=PRbSPxrOxq0ySM&hl=en&sa=X&ei=mTqFUdqeGoT4yQGQ8YCYBg&ved=0CDIQ9QEwAA&dur=375

 

I would not bolt to the cantilever. I would ask the Building Department first and see if they just missed this or if they are good with it. Even if they are good with it, I would still ask the designer for clarification or to change the design to one where the joists would go back to the sill.
If he refuses then he is a dick. Tell the HO your concerns and if he is on board with the BD and the designer build it like the plans say. If anything happens, you are on record as having brought it to every ones attention and should be in the clear.

Personally, I have never seen a deck bolted to the rim of a cantilever and do not think it is a good thing at all to do. But I do not work for the BD nor am I a licensed engineer, so what do I know.


Andy.

 

Built about 10 months ago, fully inspected by local building department and engineering stamp on the design and how we reinforced the cantilever to allow attachment.

If you're in before frame stage then just use inverted hanger on the cantilever rim, this will keep the rim from "falling" (the major fear behind attaching to cantilevers).

 

Built about 10 months ago, fully inspected by local building department and engineering stamp on the design and how we reinforced the cantilever to allow attachment.

If you're in before frame stage then just use inverted hanger on the cantilever rim, this will keep the rim from "falling" (the major fear behind attaching to cantilevers).

So, what is an inverted hangar?

 

It's simply a hanger used upside down. The bottom of the hanger goes over the top of the joists and the ears are nailed to the rim and wrap under the bottom of the rim.

 

3 days maybe 4 depending upon the finish of the house (stucco vs siding) and whether you're waterproofing beyond the beam.

 

Dam I really messed that up. I guessed one day just for the water proofing with the epdm. House has siding so little easier but still few days short. I have not gave total yet so gonna have to figure that into it. Should be a very nice deck when down though. Custom PVC 8" newel posts, PVC trim boards, metal hand rails, tiger wood with the steel frame and water proofing.

The guy knew your name when I said I got the info from you about the steel deck systems. He read your write up you did.

 

I think the inverted hanger is from the cantilever joist to the rim board, this will give the rim board much strength to hang any thing from it?

 

Hope this helps a little.

 

That's what I was talking about:blink:

 

Yea but you hadn't answered when I started drawing it and once I had it done I figured I might as well post it since I spent a few minutes drawing it.

 

The pic tells the story so much better:thumbsup:

 

I think what Griz is talking about is when the pressure is up on a cantilever. What Robert is talking about is a positive connection with ears on the rim. But please correct me if I'm wrong so I know what it's like. :whistling:

I can't seem to get your pic Rob

 

Griz,

I used sketchup, the hanger is kind of crude and probably not to spec/scale but I just wanted to get the idea out there.

Cali,
It's odd that it doesn't show up, it's hosted on my dropbox... Probably need to NOT be using the app to view it...

I try to bring up the pic and it says connection error

 

I try to bring up the pic and it says connection error

I will try it through browser

 

I thought you meant to put the hangars on the deck joist. :laughing:

Thought you had too many drinks:drink:


The picture clears that up.


my floor is glued and screwed and there is already a wall on the end of the cant. That method probably won't happen for this one, but I did learn something today:thumbsup:

 

Pack the webs of the TJI (if that's what you have) with 3/4" ply (both sides back to the wall) and add L90's to both sides. Works just as well and what we do on houses already built.

 

BD could require hold downs and all thread to make the connection from house to deck. I believe it's every 4' of ledger.

 

Good detail but I fail to see the value in putting the hangers, whether inverted ot not on the floor joists. I suppose there is some minor deflection upward on the ends of the floor joists due to activity in the house but you have the weight of the cant wall to minimize that.
I have designed inverted hangers on short lengths of deck joists that happen to be needed when they land pretty much on the beam in the middle of the length, so I see the value there.
Hanging off the cant rim simply something that I would never recommend.
Running the deck joists thru the cant to the wall is a pain in the azz sure, but if our jobs were easy then little girls would do it.

Andy.

 

Very commonplace around here and signed off on by dozens of different engineers.

You don't have to like it for it to work and meet the intent of the code.

 

Scipio,

The purpose of the inverted hanger is to resist the downward force on the rim created by the deck and, more importantly, its' live load.


Image you have the deck attached to the rim, which is then attached to the cant. joists with 16d nails. If an elephant stands on the deck near the rim, the rim will stay attached to the deck joists, but the rim will sheer off or pull out from the cant joists.

 

Image you have the deck attached to the rim, which is then attached to the cant. joists with 16d nails. If an elephant stands on the deck near the rim, the rim will stay attached to the deck joists, but the rim will sheer off or pull out from the cant joists.

Elephant:blink: just because a chick a bit thick is no reason to be rude:whistling

 

I'm not going to argue with the engineer, but aren't you in essence extending that cant by the additional length of the deck?

 

I'm sure most engineers wouldn't agree that attaching deck joists to cantilevered I-joists is a good idea.

It's not that difficult to get the load from the deck joists into the rim board, and then from the rim into the I-joists by using the inverted hanger method previously discussed.

The issue would be that I-joists do not have high shear capacities. If the floor spans on the inside of the house are long, and the spans of the deck joists are long, you could easily exceed the design capacities of the joists.

You may not get into trouble very often in the bay window situation, but doing that when the entire back of the house is cantilevered and supporting an exterior wall which supports one end of the roof trusses would be a problem.

 

You don't have to like it for it to work and meet the intent of the code.

Oh, thank you so much for that Robert, I had always assumed that I did have to like it before becoming code.

Learn something new every day.

Andy.

 

Didn't mean to sound like a jerk, I'm really tired and can't seem to sleep very well so my responses are a little short and might be taken as rude. I respect you Andy.

I don't know what engineers you guys know but I know with my engineer he doesn't just willy-nilly stamp things, if he's putting his liability on the line he want's to feel comfortable.

 

hmmm..blaming it on lack of sleep now huh?

 

Not when it comes to dealing with you, then I am just being a jerk :jester:

 

whatever you say...:clap:

 

I ws always under the impression that Adding a ledger to to the cantilever was wrong for 3 reasons,

1. pull away, from the house

2.The rimmer has a weak attachment to tji joist. so the weight of the Ledger can shear the rim joist off the tji.

3. The extra load that is be added to the ends of the cantilever joist. Forcing the joist to bear more weight.


I get the hangars will do a good job of stopping the rim joist itself from shearing off the Cantilever joist. And those fancy l90 will stop the rim joist from pulling away from the house.


I'm just wondering if you have like a 12' deck, you would be adding a lot of weight to the cantilevered joist(s)

I already have an exterior wall and roof load on the cantilever we're working on.

(just thinking out loud. )
So back to the flashing detail, any other opinions on how to flash this ?

 

Your primary roof load shouldn't be on that can't, isn't there a beam in line with the foundation and posted down to the foundation?