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Freestanding deck swaying

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freestanding lateral support swaying
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#21 ·
Should’ve been connected to the house. I can see doing the freestanding if it was all stucco, maybe, but this is vinyl sided.

Helical piers do not help with lateral movement. Depending on the soil type and length/strength of the pipe you can wiggle them around a half inch or so. Bigger commercial ones where everything is welded are stiffer.

You will never get this to feel stable without a maze of braces.

Spend a day to disassemble this and then rebuild it with a ledger attached to the house.
 
#22 ·
What do plans indicate that you submitted to the town... or this without a permit job?
What is your location and do you need hurricane straps?
Why plywood if it's a deck? If you install plywood that will prevent deck from swaying.
 
Discussion starter · #23 ·
A few comments
Here

The envelope has 2.5" continuous insulation with 1" strapping.

So a ledger board would be difficult and the existing beams over the patio are maxed out.

We are installing plywood with a PVC walkable roof membrane on that.

OBC (Ontario building code) doesn't have much on the diagonal bracing connection.

I looked at IRC and through bolts or 2 screws (0.27") are acceptable. I can't remember which one, I can look it up again in a bit.

This is with a permit.

I believe the small diagonal bracing are too high. I will double check but I think one of the guys placed them higher than indicated on the plans.
 
Discussion starter · #26 ·
Seven-Delta-FortyOne said:
What does your supervisor say about this?

At least in my area, this work would require a permit, which would require a set of plans with details based on either DCA-6 and/or the California Residential Code, or, if it was outside the purview of prescriptive Codes, an engineers stamp.

Also, from looking at the pictures closely, some of the work looks a little sloppy. What’s with the scrap of wood in the post cap? 😳

The center knee braces appear to barely be attached to the joists at the top.

And nailed knee braces are barely better than worthless. Even 8” and 10” structural screws are not much better. They need to be through-bolted, and there’s a way to do even that properly.
Click to expand...
The centre braces are running inbetween the floor joists with 4" SDWS DB screws from each side.
 
Discussion starter · #28 ·
Pounder said:
There is inadequate sheer across the face. I'd install a very heavy X brace (perhaps even a sheer wall) in one of the rear bays and use the plywood deck to transfer the sheer load to the rear.
Click to expand...
After we plywood and blocking.
We may install Chevron bracing along the middle bay away from the house and closer to the house.
 
#29 ·
2010G37x said:
To where?
Click to expand...
I was talking about the joist hangers fasteners. Often I can use .62 galvanized 3" or better on hangers requiring additional hold, or going through a packed out area.

This often requires sheer calculations for your region as the Simpson hanger screws have better sheer ratings...and/or are uniform and rated specifically for hanger applications. However, they are short, and not applicable when attempting to grab the structural wood member THROUGH a packed out area.
 
Discussion starter · #31 ·
META said:
I was talking about the joist hangers fasteners. Often I can use .62 galvanized 3" or better on hangers requiring additional hold, or going through a packed out area.

This often requires sheer calculations for your region as the Simpson hanger screws have better sheer ratings...and/or are uniform and rated specifically for hanger applications. However, they are short, and not applicable when attempting to grab the structural wood member THROUGH a packed out area.
Click to expand...
you referring at the blocking?

for the hurricane ties I am using #9 x 1.5". I will see if switching them to #10.

I am not sure how much help that will be.

or are you referring to the beam connection?
 
#32 ·
That just looks like a bad design. Those diagonals are way too high from a structural standpoint, it would never get through plans examination around here. They were probably designed high up for aesthetics, as to not obstruct the view, but there are other ways to design it structurally sound and make it look better.

It sounds like you're not interpreting the building code correctly. No need looking at the IRC if you're in Canada, it doesn't apply there. I don't know what's in the Ontario Building Code but building code literature for engineering usually isn't as straight forward as 'what kind of diagonals do I need?'. That's probably why you're not finding it in there, there's moment and shear calculations you need to determine what kind of bracing goes in.

Did you design this yourself or did you hire someone? If it's swaying, I'd tell the designer to get over there. If you designed it yourself, I'd make some changes to those diagnals and send it to your engineer.
 
Discussion starter · #33 ·
Seven-Delta-FortyOne said:
What does your supervisor say about this?

At least in my area, this work would require a permit, which would require a set of plans with details based on either DCA-6 and/or the California Residential Code, or, if it was outside the purview of prescriptive Codes, an engineers stamp.

Also, from looking at the pictures closely, some of the work looks a little sloppy. What’s with the scrap of wood in the post cap? 😳

The center knee braces appear to barely be attached to the joists at the top.

And nailed knee braces are barely better than worthless. Even 8” and 10” structural screws are not much better. They need to be through-bolted, and there’s a way to do even that properly.
Click to expand...
It's not really possible to put a 5/8" bolt through a 11.25" built up beam. with the built up beam you don't have room to drill out most of the core. that's why screws were used.

Image
 
#36 ·
2010G37x said:
the code here doesn't have code regarding diagonal bracing. we originally had the diagonal braces at 1/3 2/3 location of the post. they were installed under that.
Click to expand...
I looked up the Ontario Building Code online, they do have rules for diagonal bracing. It starts out with this:

p = IwqCeCgCp

Did you do the calculation to get your wind load?
 
#39 ·
Look up the definition of 'storey', whenever something is in asterisk that means they have their own definition which is different than the dictionaries definition. That could play a role in your design, I don't know. According to section (3)(c) 'extend the full height of the wall on each storey'. You would need those diagonals to extend a lot further than that. Wind loads still apply though or they wouldn't have the equations on wind load in there.

That's why you need an engineer man, you are trying to engineer it yourself and running into problems. Sure you can guess on the engineering but the liability comes down on you if it comes tumbling down. Or even if it doesn't come down, the liability is on you if someone looks at it and says 'You didn't do it right, I'm not paying you'.
 
#40 ·
2010G37x said:
It's not really possible to put a 5/8" bolt through a 11.25" built up beam. with the built up beam you don't have room to drill out most of the core. that's why screws were used.

View attachment 566064
Click to expand...
It can be done. It’s a pain in the ass. You need a long auger bit, and you need to plan your layout so the bolt head doesnt land where a joist lands.

If you’re hanging joists off the face, that really complicates it.
 
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deckman22
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