Rear deck kicker support

[Bammer25]

Has anyone tried eliminating the rear posts and using a 45 degree kicker back to block wall (or footer). This is a steep hill and my client wants to eliminate more footers and piers. Seems pretty simple but I am having a rough time figuring out the best connection. A 6x6 post diagonally connecting back to the band/double 2x12 is putting way too much shear perpendicular to grain that I would need a million bolts. Any cool ideas? Obviously the wood is the weak link. Other end of deck will be a ledger.

 

[XR250]

Seems pretty simple

These are absolutely not simple. Getting all the connections and load pads right is difficult. I generally avoid them when possible.

 

[Bammer25]

I am finding this out. He has a cool fab guy so I can detail steel plates and cool connectors but eventually you have to have the load go through the wood.

I believe I have a good way but it will add material and add depth to the deck. Basically have a double 2x (tension member) on a ledger at the cabin and the other end supported by the kicker. Two 7/8 bud bearing with the grain connected by steel plates down to the angled post which goes to footer. One of these scenarios for each post location and then the deck would sort of just sit on top.

 

[SWComposites]

Maybe use diagonal steel posts?

 

[XR250]

Pull-out from the house is usually a big hurdle.

 

[Bammer25]

If it was a wood framed rear wall I could use those Simpson tension ties to the interior trusses. Grouted block and anchors are great but how to transfer that to the wood?

 

[XR250]

You would have to have enough diaphragm to transfer the point pull-out load at the brace to the distributed connection at each truss. Since there typically is no diaphragm on a deck, then you would have to to react the entire pull out in one location. That can be challenging. Most engineers overlook about 50% of the load paths on these jobs.

 

[kipfoot]

I agree with xr250. maybe there's a solution if the owner can accept that resisting these forces will require a significant connection to the floor framing system of the structure. Something like: long steel rods anchored at multiple points along the length of the floor framing and a plate washer resisting the force through compression on the outside end. make it so that the diagonal can't fail unless the whole cabin goes with it.

 

[phamENG]

Can you post a sketch to show how the alignment works? Might make it a bit easier to spitball ideas.

make it so that the diagonal can't fail unless the whole cabin goes with it.

But then also make sure the cabin doesn't do that.

 

[EdStainless]

I knew someone with a cabin with a deck like this.
It is still there 60 years later for what that is worth.
There are steel tie rods that connect to plates on the outside of the outer frame of the deck and then extend clear through the block wall.
There is a channel the full width of the deck at both ends of this.
The 45s are steel because he wanted to minimize seasonal movement.

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P.E. Metallurgy, consulting work welcomed

 

[XR250]

60 years and likely has only had a few people on it at a time. I love going to the beach and seeing three stories of balconies supported on diagonal braces at the bottom to increase the parking area. Scary AF and usually sagging.

 

[phamENG]

going to the beach and seeing three stories of balconies supported on diagonal braces

My wife goes through cycles of annoyance and humor at my constant warnings for my kids not to lean on the railings at the beach cottages...

 

[EdStainless]

This one overlooks Lake Huron and I have been there when the deck had 50 people on it, 4-5 deep all along the outer edge.
Not a sound or movement.
The lumber was locally sourced rough sawn and oversized by today's standards.
Overbuilt AF. The only way a deck should be built.
I don't know the details of the block wall that this is tied to.
But knowing the guy who built it I am guessing that that section of wall is all filled cores with steel in at least every other one.


= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[Bammer25]

Well at least I know I wasn’t crazy when my forces I resolved were not cooperating with the lumber

 

[Bammer25]

I have a 16” rise and an 8 foot run so there’s that. I’m going to think on it some more.

 

[XR250]

My wife goes through cycles of annoyance and humor at my constant warnings for my kids not to lean on the railings at the beach cottages...

Ha!. I tell my kids to never ever lean on ANY deck guardrail.

 

[Once20036]

I was at a lumber yard last week and spotted a second story deck that matches this style. Unfortunately I was with the family and they wouldn't tolerate a closer inspection into the attachment methods.

 

[Bammer25]

I ended up getting the numbers to work out pretty well with an 8x8 kicker. Vertical load transmitted in bearing and the thrust I transmitted using 1” diameter bolts with steel plates sandwiching a triple 2x12. Tied back into the masonry block with multiple Simpson tension ties. I feel sorry for the guys that have to manhandle that 8x8 up there