Structural integrity of deck

LeeMajors said:
I think I'd just do it the way you want. Save the x timbers and put them back when you decide to sell
Click to expand...
Ok, so if we consider that plan...

What’s more important structurally...the “at least 1/3 the length” of the post or the 45°-60° angle? Better to go less than 1/3 of the way down the post but keep it at least 45° (green), or go 1/3 of the way down and have a smaller angle (blue)? Not drawn to scale, but exaggerated to show what I meant.

AAA9422F-BA3C-4131-A6A7-8B52525A993A.jpeg
 
BigWaylon said:
Ok, so if we consider that plan...

What’s more important structurally...the “at least 1/3 the length” of the post or the 45°-60° angle? Better to go less than 1/3 of the way down the post but keep it at least 45° (green), or go 1/3 of the way down and have a smaller angle (blue)? Not drawn to scale, but exaggerated to show what I meant.

View attachment 254218
Click to expand...
IF it were mine I'd go 60 on the 2 smaller and 45 on the middle
 
BigWaylon said:
Ok, so if we consider that plan...

What’s more important structurally...the “at least 1/3 the length” of the post or the 45°-60° angle? Better to go less than 1/3 of the way down the post but keep it at least 45° (green), or go 1/3 of the way down and have a smaller angle (blue)? Not drawn to scale, but exaggerated to show what I meant.

View attachment 254218
Click to expand...
The angular window of 45-60 degrees is optimum for load transfer to the column. Any steeper and the support would want to slip down the column. Any flatter and it’s pushing too much laterally into the column which would induce a buckle. 45 degrees is optimum.

The 1/3 length is also trying to prevent a buckling from happening. A column is most susceptible to buckling if a load is applied at the midpoint. So keeping it away from that point is ideal.
 
...and is cutting a spacer to use between a brace and the post a worthwhile endeavor so there’s one hole at the top (right), or use two holes at the top (left) and cut the braces so they meet on the same plane. On the right side, there would be a spacer between the bottom of blue brace and the post.

(really crude sketch, but you get the idea)

CB51661E-A2A4-44EC-8259-7D38471C4136.jpeg
 
BigWaylon said:
...and is cutting a spacer to use between a brace and the post a worthwhile endeavor so there’s one hole at the top (right), or use two holes at the top (left) and cut the braces so they meet on the same plane. On the right side, there would be a spacer between the bottom of blue brace and the post.

(really crude sketch, but you get the idea)

View attachment 254221
Click to expand...
Just notch them to overlap
 
9outof10mms said:
The angular window of 45-60 degrees is optimum for load transfer to the column. Any steeper and the support would want to slip down the column. Any flatter and it’s pushing too much laterally into the column which would induce a buckle. 45 degrees is optimum.

The 1/3 length is also trying to prevent a buckling from happening. A column is most susceptible to buckling if a load is applied at the midpoint. So keeping it away from that point is ideal.
Click to expand...
Cool. So 45°, which puts me closer to the top of the post instead of more towards the middle.
 
My thought from the PDF diagram is that “block” meant there should be a block between the two braces where they cross, with a bolt running through it. So, maybe a spacer on the post isn’t a bad idea. But I have no idea. :confused:
 
BigWaylon said:
My thought from the PDF diagram is that “block” meant there should be a block between the two braces where they cross, with a bolt running through it. So, maybe a spacer on the post isn’t a bad idea. But I have no idea. :confused:
Click to expand...
Actually it will look like this 20201006_211755.png
 
Bought a drill bit, several bags of Quikrete, 30 nuts and 30 washers at HD this morning, along with four 2x6x8 boards.

I’d ordered one item (~$35) from Grainger last night and had a hard time deciding which shipping option to go with:

C57B2E00-E2F8-4EBB-B3AF-7A5C37BA6E61.jpeg

:eek:
 
Thinking of your numbers again. You said that there is 70" between the posts. Half of that is 35". You said that it's 98" from the ground to where the post meets the deck, but the top of the post is a little higher. That looks like it's a 2x6 or so, so call it 104" or to make the numbers nice, 105". 1/3 of 105" is 35". Going down, 35" and across 35" gives you your 45 degree angle and you're 1/3 the way down the post, meeting both spec items.
 
Had a member come over today and we talked about it some more. Decided what I’d do is keep the X braces on the end, but move them up. Haven’t attached everything because I’m waiting on some new hardware to arrive tomorrow, but I mocked up the two ends and I can walk under the center of each X.

So the left & right sections will look like this:

EF66CB85-E68B-4D0E-93A4-FF5E8E10A9E6.jpeg

I'm going to add a block in the middle with a bolt through the two braces, which it didn’t have (but I think should’ve have had) before. The last little decision is to decide if I go 45° (blue) from the hole I drilled in the two middle posts up to the deck, or if I take them all the way to the center (green) to meet but not overlap.

DBACE428-5311-48D3-B1D1-F4757B71E691.jpeg

Whichever I decide, I’d do roughly the same angle from the two end posts towards the house. That’s adding two braces that aren’t already there. Just have to go up or down on the post a little so I don’t hit the bolt already there.
 
BigWaylon said:
Had a member come over today and we talked about it some more. Decided what I’d do is keep the X braces on the end, but move them up. Haven’t attached everything because I’m waiting on some new hardware to arrive tomorrow, but I mocked up the two ends and I can walk under the center of each X.

So the left & right sections will look like this:

View attachment 254702

I'm going to add a block in the middle with a bolt through the two braces, which it didn’t have (but I think should’ve have had) before. The last little decision is to decide if I go 45° (blue) from the hole I drilled in the two middle posts up to the deck, or if I take them all the way to the center (green) to meet but not overlap.

View attachment 254704

Whichever I decide, I’d do roughly the same angle from the two end posts towards the house. That’s adding two braces that aren’t already there. Just have to go up or down on the post a little so I don’t hit the bolt already there.
Click to expand...
Green
 
LeeMajors said:
Green
Click to expand...
That’s what I was thinking. But instead of notching and overlapping, cut the ends at an angle so they meet each other in a vertical line.

or should I go with a single hole and the overlap?
 
BigWaylon said:
That’s what I was thinking. But instead of notching and overlapping, cut the ends at an angle so they meet each other in a vertical line.

or should I go with a single hole and the overlap?
Click to expand...
I thought you were going to leave a space between them. If you angle the ends you will be making the ends weak where the bolts go through
 
LeeMajors said:
I thought you were going to leave a space between them. If you angle the ends you will be making the ends weak where the bolts go through
Click to expand...
I can do that, too...leave enough space that the lower corners touch and not cut any angle.

Or do the overlap...
 
Hopefully they ended up above head height! If not and your like me it will really piss you off when you walk into one and peel the skin off your head.
 
Jp8819 said:
Hopefully they ended up above head height! If not and your like me it will really piss you off when you walk into one and peel the skin off your head.
Click to expand...
I can walk under all three. Not close to the post, but at least in the center.
 
ronn47 said:
@BigWaylon what did you do about the bottom of the posts?
Click to expand...
Nothing, yet...other than buying some Quikrete. Wanted to get the bracing done first so I only had to mix it once. Since the patio was poured after the deck was built, I had some areas around the other posts that will need to be filled in once I removed the braces that were basically at ground level. For example:

BD4E1144-0EB7-4C8D-9CB7-258A79FB1D0C.jpeg 64215B23-AB82-479F-A425-467547296C16.jpeg

Still waiting on my Grainger delivery to finish it all up. Supposed to be today, but who knows?

Once it’s here I can tighten everything up and do final trim on the braces. Plan is to cut the bottom of the post off and pour a footing. Might use one of the brackets, might not.
 
I have a Stihl concrete saw if you happen to need it. I have no reason to have it other than my neighbor was having a yardsale a few years ago and I bought a bunch of tools cheap. Just got it out last weekend to make sure it still ran OK as my dad is thinking about changing up a walkway.
 
The 12’ piece of threaded rod showed up yesterday, so I cut all my pieces this morning and swapped out the new hardware.

Got the two blocks in place. Here’s one:

1E8F9249-940D-46D9-90BB-CFE6866AB764.jpeg

Everything feels real sturdy. All that’s left at this point with the braces is to trim a few ends. I also need to buy two more nuts and washers. Instead of having two extra, I ended up being short two...thanks to a last minute change in design (using the X design instead of overlapping boards at the top). But, I’m also able to return the four 2x6x12 pieces of lumber I bought. Yay!

up next, once we have a dry spell...the post/concrete part of the job
 
You must log in or register to reply here.
Back
Top Bottom