# Fixing out of square deck posts



## Scuba_Dave (Jan 16, 2009)

Where are you located ?
Pics of the issue ?
How far off the ground is the deck ?


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## Starbuck II (Apr 28, 2010)

I don't have pics, the deck is only going to be about 8" off the ground, but there is a roof that will be over it using 4x10's & so that can't be forced to align.

Think of a rectangle with a corner clipped off. 

Sides would be 12', 10', 8', 8' & 40" 

the 12' side is 3" out of square by the end of the run.
the 8' side that connects to that 12' side is also 3" out of square.

any ideas how to straighten it?


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## tpolk (Nov 7, 2009)

is that 3" on the diagonal? so only 1.5 to square it?


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## Yoyizit (Jul 11, 2008)

Starbuck II said:


> dig around the footings & move or pry par the 200lbs plus footings the needed 3"?


And then pour more concrete in the enlarged hole. This might be the best option.


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## 12penny (Nov 21, 2008)

starbuck... I think I'd move the post bases/anchors. Not sure which ones you're using. If they're simpson bases just cut off your anchor bolt, drill another hole and install some kind of wedge anchor to hold the base down. Sure beats digging them out.


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## Starbuck II (Apr 28, 2010)

The 3" is on the perpendicular.

The anchors aren't bolts. They are the kind where there is significant steel in the concrete. cutting them off would not work because there is steel embedded in the concrete where I would have to drill.

I wished that would work. 

I have thought that maybe adding a short daughter post in the mount then attaching the real post to it with bolts. I am afraid that however wouldn't give me the load bearing value I need.

I wished I knew a better way than digging. Anyone got any other ideas?


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## Willie T (Jan 29, 2009)

SB II said:


> I used the 3,4,5 rule, everything looked good. I dug the holes, put in concrete tubes, filled them with concrete installed the post anchors while the concrete was wet, checked 3,4,5 again, it all looked good.


Contrary to popular belief, the method described is really not all that accurate, if not also checked by pulling diagonal measurements.

Seriously, the 3,4,5 rule (or the 6,8,10 rule) is good only for *roughly* getting you in the *ballpark* of a 90 degree corner.

Each time you turn a corner and reapply your 3,4,5 rule, you introduce an additional chance for error. And if the actual numbers used are not almost as long as the deck run, itself, there is still more chance for error.

Always use the Pythagorean Theorem to determine your true diagonal measurements. And double check just before cutting any boards.

It honestly is not all that likely that some rain, alone, caused this much of an error. And I say this because you wrote that you didn't check again when you returned home, but rather drilled to the holes where they lay... and the fact that everything is still 'very level', reinforces the premise that nothing moved. If the columns shifted, they would have done so by tilting and/or sinking, not by smoothly moving in a parallel and vertically plumb attitude.

I know this doesn't help you much with this current dilemma......... but I'm writing this for the next guy here who decides to just pull a 3,4,5.

Also.................. You will NOT be able to move the columns and retain level accuracy by digging down along side them, then trying to pry them sideways. The tops will move, but the bottoms will resist.... and they will scuff themselves deeper into the ground as you attempt to move them. This is not a big deal, as you can always make the posts for those columns longer... but keeping them plumb is going to be a monumental task.


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## Starbuck II (Apr 28, 2010)

So is there any solution at all? is there anyway to fix this short of blowing it up & starting over?


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## Yoyizit (Jul 11, 2008)

Willie T said:


> Seriously, the 3,4,5 rule (or the 6,8,10 rule) is good only for *roughly* getting you in the *ballpark* of a 90 degree corner.


No.
The arctan of 4/3 is 53.1° and the arctan of 3/4 is 36.9°.
This totals to 90.0°. 
The remaining angle must then be 90.0°.

3" out of 12' is a 1.2° error. This error magnitude may reflect ordinary effort, given the conditions you worked under. With extraordinary effort you might significantly reduce this error.

5:12:13 also works, and this seems more suited to your dims. Using aluminum angle to make this huge square will assure straight sides and high accuracy. And you can fold up the whole thing.

Surveyors, of course, would want much better, over a distance of 12'.
http://www.google.com/search?client=safari&rls=en&q=transit+accuracy+surveying&ie=UTF-8&oe=UTF-8


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## Willie T (Jan 29, 2009)

Yoyizit said:


> No.
> The arctan of 4/3 is 53.1° and the arctan of 3/4 is 36.9°.
> This totals to 90.0°.
> The remaining angle must then be 90.0°.
> ...


And you know anyone who can hold a drooping tape measure (perhaps two of them from two different directions at once) to within a tenth of an degree?

Sorry. Too many decades in the field dealing with this kind of error says it ain't gonna happen. :no:


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## Willie T (Jan 29, 2009)

Starbuck II said:


> So is there any solution at all? is there anyway to fix this short of blowing it up & starting over?


It is really only a problem because of the steel fixtures. If you can get them out of the way, drilling in new ones in the existing columns would probably get things close enough.

It would shock you how many houses get built where the walls miss their intended relationship to the footings by as much as you are talking about here.


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## Starbuck II (Apr 28, 2010)

Hmm,

but that would then place the post at the edge of the footing, not anywhere close to putting the roof load on the center of the footing so I would be afraid that the load could crack the concrete.

Also the anchors are fairly large inside the concrete so I would probably run into metal a few inches down.

any other approaches?


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## kwikfishron (Mar 11, 2010)

Small deck, small roof, small footing, I’d be moving it, but that’s just me.


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## Starbuck II (Apr 28, 2010)

moving what? the footing? the anchor point?
Please clarify


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## kwikfishron (Mar 11, 2010)

Starbuck II said:


> moving what? *the footing*? the anchor point?
> Please clarify


The Footing.

I’ve screwed up before, I’ve done this before and all is fine. 

I’m sure I’ll get a thrashing for suggesting this.


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## tpolk (Nov 7, 2009)

how tall are the posts on the footing and is a beam on this?


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## Willie T (Jan 29, 2009)

kwikfishron said:


> The Footing.
> 
> I’ve screwed up before, I’ve done this before and all is fine.
> 
> I’m sure I’ll get a thrashing for suggesting this.


Most of us with any appreciable amount of experience in any industry have covered our butts with a host of creative solutions. Construction just takes more physical and dynamic fixes.

I have very little doubt that if we were able to lay eyes on the real world problem, you might have at least two or three possible ways out of this. As it stands right now, it is difficult for any of us to suggest 'outside-the-box' thinking because we are really not all that sure exactly what the _box_ looks like.

As I said, we don't really know where and how and to what extent, on which columns you're off. And we don't know your plan of building or if it can be modified.

Think 'offsets' and/or 'cantelievers', and reversing direction on joist layouts, etc. Even enlarging the perimeter to 4 or 6 inches larger to give you space and flexibility to square up the outside rim. Ya gotta get outside the box on this one.


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## Starbuck II (Apr 28, 2010)

Polk,

Posts are 8' tall, yes beams will sit on top of the posts with Simpson brackets. 

Willy,

I am going to re string line the whole space to get more accurate measurements because it's difficult to see them as out of square given that none of the rim joists are 3" away from one post to another.

The shape is a rectangle with one corner lopped off. An exagerated view would be somewhat trapazoidal. There is a 12' side, adjacent to it is a 10' side. Adjacent to the 10' side is an 8' side. On the other end of the 12' side is an 8' side. The two 8' sides are connected by a 40" side.

I have since given some thought to cantilever, but I am concerned that The roof load isn't properly transferred to the footing.


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## Starbuck II (Apr 28, 2010)

The posts are impossible to move unless I destroy them. 
I think there really isn't any solution for making this square that doesn't involve totally starting over.

I think I found out one thing that happened for sure, a couple of the anchors moved during curing, about 1.6 degrees by my calc. I used a square laser to generate two perpendicular lines. It seems that a couple anchors are rotated slightly & a couple footings are off axis by 1" That combination seems to be what has generated most of my errors.

I think my only hope is to start the decking from the centre & work outwards towards the perimeter & fudge the gaps a little bit all the way across. leaving any error to be along the outside edges.

Not sure what else to do. Anyone else got any ideas? I have looked over cantilevering the post to the anchor, but that to me seems like it would weaken the support for the roof.


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## kwikfishron (Mar 11, 2010)

Can you post some pictures?


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## Starbuck II (Apr 28, 2010)

I will try but I don't think you would see anything. The errors are not obvious when you look at it. I am working on some sketches with dimensions that might give a better picture.


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## kwikfishron (Mar 11, 2010)

I’d sure like to see a picture of your footings and the wall your building off of in the same shot. Don’t need to see out of square part in the picture.


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## Yoyizit (Jul 11, 2008)

Yes, get a very accurate centrally located post and work out from that in a star pattern, rather than starting at one end and working around in a daisy chain. This second method adds each error to the one before it.


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