How to limit sideways movement? 4 post gazebo

[ktro...@hotmail.com]

I live in Phoenix,AZ.

I hired someone to build a FREE STANDING 12' X 12' (from post to
post), 4 post structure (similar to a gazebo) for shade in my
backyard.

Posts are wood and 6"x6". Two of the posts(on one side) are on top of a
existing concrete pool deck, the two other side posts have a concrete
footing. All post where nailed to a steel fastener that was bolted to
the concrete.

I am seeing alot of sideways movement, I was hoping that after the roof
framing was put on top that it would stiffen up the structure, but it
seems to have made it worse.

I would be most appreciative if anyone would have any solutions to this
problem?

My ideas have been to:
Keep in mind that i know next to nothing about construction?

1. Replace the wood posts with steel posts, (but how to fasten to
concrete slab/footings?)
2. Replace with concrete/brick either around the existing wood are
possible haflway up the post?
3. Place steel around the bottom of the post ?
4. Put structure supports from under side of roof to top of posts.

Any feedback would be greatly appreciated!!!

Thanks, Kevin Troendle

[tb...@bellsouth.net]

It's not the material of the posts.
It's the connections.
The frame needs either moment connections or triangulation.
Without knowing more about heights and roof, it's hard to be more
specific.
TB

[SteveF]

<ktro...@hotmail.com> wrote in message
news:1144131468.4...@i39g2000cwa.googlegroups.com...

First thing I would do is to get some 3" deck screws and put about 4 into
each piece of wood connected to the posts. Assuming you have 2" x 6"s as
cross pieces you want to first drill a hole through the 2" x 6" that is the
same diameter as the screw shaft. Shaft, not head, you should see some
thread sticking out when you hold the drill against the screw. But NOT into
the post, only go 1 1/2" deep. Put a piece of masking tape on the drill so
you know where to stop. This will make the screw pull the 2" x 6" tight
against the post when you do the final tightening. Spread the screws as far
apart as possible on the face of the cross piece.

If that doesn't work you will need to make some pieces that go diagonally
from the posts up to the cross pieces. Attach with deck screws. They don't
need to be big.

Steve.

[Bob Morrison]

In a previous post tb...@bellsouth.net wrote...

I agree with Tom. It's the connections. You need some knee braces in the
corners or you you need some kind of moment transfer connection at the
upper corner. It is very hard to get this type of connection with a wood-
to-wood connection.

The knees can be 4x4's or pieces of steel tube or pipe.

--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com

[clintonG]

As I understand your problem your structure is compromised by wind loads and
uneven distribution of dead loads (roof and so on) which causes the
structure to rack under load. If that is correct put on your thinking cap
with me for a moment. Racking works like a lever. Somewhere, the lever is
fixed and the rest of the lever attempts to be in motion when some load
pushed on the lever. Are you with me? The lever is "fixed" where it is
nailed to the steel fastners which were bolted to the concrete.

The wind loads are causing the lever to move back and forth. Where the lever
is fixed is the point of rotation that the lever is attempting to rotate
around. If your having problems picturing this just put a pencil on top of
your desk standing straight up on its end eraser side down. The eraser is
"fixed" to the deck and the free end wants to move when you push on it (wind
load). That is rotation around the fixed point. Get it?

So as I "see" the problem you have improper connections (for the
circumstances) which are insufficient to resist the levering action. You can
check this yourself by getting down to ground level and looking very closely
at the connection(s) where the posts are nailed to the steel fasteners. You
should see signs of nails starting to move, the nail holes starting to
enlargen and so on.

How to respond?

The cheapest -- and secure -- way may be to bolt equilateral triangular
corner braces onto each post. The base of each triangle should rest on the
concrete pad. This type of bracing will resist the rotating lever action.
You see this all the time on pole construction only the braces are at the
top of the post and form a Y when you look at the post and its braces. You
getting the picture? Turn the Y upside down, use solid material to form the
"top" of the Y which is now the "bottom" and rest the bottom of that
triangle the Y forms onto the surface of the concrete and you have an
inexpensive bracing solution that should resist all but the heaviest of wind
loads.

The best way to build post construction however would have been to pop a
hole through the concrete and set the posts into the ground so they would
not rotate around their connections. In any event, your current problem is
where the posts are connected to the concrete.

<%= Clinton Gallagher
NET csgallagher AT metromilwaukee.com
URL http://clintongallagher.metromilwaukee.com/

<ktro...@hotmail.com> wrote in message
news:1144131468.4...@i39g2000cwa.googlegroups.com...

[Bob Morrison]

In a previous post clintonG wrote...

> The cheapest -- and secure -- way may be to bolt equilateral triangular
> corner braces onto each post. The base of each triangle should rest on the
> concrete pad. This type of bracing will resist the rotating lever action.
> You see this all the time on pole construction only the braces are at the
> top of the post and form a Y when you look at the post and its braces. You
> getting the picture? Turn the Y upside down, use solid material to form the
> "top" of the Y which is now the "bottom" and rest the bottom of that
> triangle the Y forms onto the surface of the concrete and you have an
> inexpensive bracing solution that should resist all but the heaviest of wind
> loads.

Clinton:

You are on the right track, but putting the braces at the bottom of the
posts represents a serious trip hazard and so is not really very safe. It
is generally better to put the braces at the top where they can easily be
seen, or depending on the height of the structure the braces may even be
put above head height.

[willshak]

The triangular bracing should be at the top of the posts where the
connection between the posts and roof connect and where the 'lever'
movement occurs. Besides, putting the bracing at the bottom would be
unsafe due to the possibility of tripping over the bracing.

--
Bill
In Hamptonburgh, NY

[HerHusband]

> You are on the right track, but putting the braces at the bottom of
> the posts represents a serious trip hazard and so is not really very
> safe.

What if the braces were being built inside a railing or wall around the
base of the structure?

Personally, I'd rather have the bracing hidden in the lower railing that's
there already, than have additional obstructions up higher.

Are there any structural advantages to having the braces at the roof
instead of at the bottom?

Anthony

[Bob Morrison]

In a previous post HerHusband wrote...

> What if the braces were being built inside a railing or wall around the
> base of the structure?
>
> Personally, I'd rather have the bracing hidden in the lower railing that's
> there already, than have additional obstructions up higher.

That's a good idea if railing or wall exists or could be added. Typically
that is not the case however.

>
> Are there any structural advantages to having the braces at the roof
> instead of at the bottom?
>

No. Top or bottom works the same. It just needs to be done.

[clintonG]

Thanks for commenting Bob.
I had to run out and do some family obligations and couldn't take time to
explain further (or even think it through further) but yes, as I proposed
the traingular braces could represent a hazard.

Perhaps a "skirt" all around the base on three sides backed by lattice laid
up to the height of a hand rail which would stiffen the frame even more with
Y bracing at the top of the two remaining posts that would then be the only
egress in and out of the space noting this solution would work without
posing a hazard but would restrict egress.

Putting all Y bracing at the top of the posts seems to be the better
solution but without more understanding of wind loads in the region I would
still be concerned about the posts at their base and so would Dorothy and
Toto ;-)

<%= Clinton Gallagher

"Bob Morrison" <SpamF...@junk.com> wrote in message
news:MPG.1e9c54122...@news.west.earthlink.net...

[ktro...@hotmail.com]

I wanted to post a few more details about this, because I think it
would help

1. The sideways movement is caused when i push on the sides
of the posts with my hand, and it seems to have way to much
movenment there.

2.The structure is at the framing stage, its not completed.
Right now only the posts and some of the main rafters are in place
however it still seems the framing that was added on top has made
it
more unstable.

3. The structure is 12' X 12' from post to post and approx 14' X 14' at
roof edges,
the bottom of the roof line is appox 7' and has a four sided
pyrmaid top, so the height at top is aprox 10'

4. The posts DO NOT extend into the ground only bolted on top of
concrete posts and slabs

Sounds like from the comments that no one is saying that the footings
need to be redone (with posts under ground level )
or the posts should be concrete or steel?

Should i allow the builder to add the rest of the roof?
He thinks this will "Tie everything together"

I may post a picture link here, think that would help as well...

Thanks, All I don't want this thing coming down on and hurting
anyone...

[DanG]

There is no requirement for the "columns" to be buried in
concrete. Doing so would have little or no effect on reducing
the swaying you describe. There is, however a lot of uplift on
the "columns". I don't know what kind of bolts are holding them
down to the concrete, but they better designed and sized to deal
with the uplift and turnover of the structure. Installing the
roof alone will only add to the problem by placing more weight
higher in the air, catching more wind, and causing more uplift.

Knee braces, x-bracing, shear walls, etc are all ways to deal with
the problem. You should not be able to make the roof sway back
and forth. Strong wind will push much harder than you can.
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)
dgri...@7cox.net

<ktro...@hotmail.com> wrote in message
news:1144184689.9...@t31g2000cwb.googlegroups.com...

[SteveF]

<ktro...@hotmail.com> wrote in message
news:1144184689.9...@t31g2000cwb.googlegroups.com...

HOOOOOLD THE PHONE!

This is still under construction?!

As someone who admits he knows "next to nothing" about construction, how
about waiting until it's finished before you decide the guy that you hired
to build it doesn't know what he's doing. Or (bizarre idea) maybe you could
ask him to show you how he is planning to stiffen the structure.

Steve.

[Moisés Nacio]

<ktro...@hotmail.com> wrote
>I live in Phoenix,AZ.

> Any feedback would be greatly appreciated!!!

<snip>

This link should give you an idea, on how to proceed. I would modify as
needed, for aesthetics and functionality.

http://images.google.com/images?svnum=10&hl=en&lr=&q=pergola+bracing&btnG=Search

[clintonG]

Neither one of them know what they are doing and to make matters worse the
OP doesn't know how to read or he wouldn't need to continue discussing
anything as his problem has already been correctly identified by at least
three different people two of which also already discussed how to resolve
the problem. Time to move on...

<%= Clinton Gallagher
NET csgallagher AT metromilwaukee.com
URL http://clintongallagher.metromilwaukee.com/

"SteveF" <no...@none.com> wrote in message
news:23EYf.37$m6...@bignews8.bellsouth.net...

[ktro...@hotmail.com]

Pictures are worth a thousand words .. use this link i have some
pictures that should explain everything.
http://www.firedrum.com/my_project.html

Actually I do know a little about constuction, but not about building
this type of structure.
I have built and done my share of backyard and home projects.
I am a Software Engineer by trade so I am very capable of seeing a
potential problem
and trying to resolve it before the project is done and its more
difficult to deal with.

I have made my concerns to the builder and HOPEFULLY we can sure things
up
using the braces and brackets that you all have suggested at this stage
you can push
the top of the post and move it very easily about an inch or more.

I appreciate the group's inputs very much. Since were potentially
dealing with a safety hazzard
here as a apposed to something in your backyard that maybe doesn't look
perferct or isn't
built totally correct, but poses no harm ... like a bar for example.

Thanks ALL!!!

[ktro...@hotmail.com]

Correction on my post above...

The movement is about 1/4 to possibly 1/2 inch at the top of the post.

[Bobk207]

overall the construction looks pretty decent EXCEPT

the structure as no lateral stiffness & those post bases suck.

Luckily you're in AZ so water / dry rot of post bases is not a huge
issue
(I would suggest Simpson EPB66 post base instead of the ones he used)

you'll need some sort of braces in the upper corners (post to beam)

doesn't your city have some sort of suggested patio cover designs?

btw I was under the impression that software engineers typically tried
to identify & fix problems AFTER the project is complete, has been
shipped & the end user finds & reports the problems..............

Ship it, we can fix it later................:)

cheers
Bob

[Bob Morrison]

In a previous post ktro...@hotmail.com wrote...

> I have made my concerns to the builder and HOPEFULLY we can sure things
> up
> using the braces and brackets that you all have suggested at this stage
> you can push
> the top of the post and move it very easily about an inch or more.
>

You could try adding Simpson RCBZ at top corners. This is a small metal
version of the knee braces I was suggesting earlier. Other options
include Simpson RTA4.

You may even be able to buy a heavy duty closet shelf bracket. Use the
groove for the closet rod to hang plants.

[Bill]

Notice the "triangular" bracing near the top of the posts on the
following...
http://gazebodepot.com/newstore/proddetail.asp?prod=BreezePavilion

[CWatters]

<ktro...@hotmail.com> wrote in message
news:1144184689.9...@t31g2000cwb.googlegroups.com...

> I wanted to post a few more details about this, because I think it
> would help
>
> 1. The sideways movement is caused when i push on the sides
> of the posts with my hand, and it seems to have way to much
> movenment there.

Perhaps the braces/diagonals shown on this image haven't been installed
yet?...
http://www.skydance.com/hearthstonehomes/goodies/images/photo-full-203.jpg

[willshak]

ktro...@hotmail.com wrote:
> Pictures are worth a thousand words .. use this link i have some
> pictures that should explain everything.
> http://www.firedrum.com/my_project.html

The finished product's posts will be no more stable than they are now.
It will have more weight on the top after the roof is finished, which
will provide more downward force, but downward force is not the problem
with the lateral movement, it might even result in more wind caused
lateral movement due to the increased mass on top.
The best thing to do is wait until the builder says it is done, then try
to move the posts. If you are not satisfied, tell him to put braces
between the posts and beams. Make sure they are decorative to your
liking and not just some rough planks or plywood gussets nailed up there.

>
> Actually I do know a little about constuction, but not about building
> this type of structure.
> I have built and done my share of backyard and home projects.
> I am a Software Engineer by trade so I am very capable of seeing a
> potential problem
> and trying to resolve it before the project is done and its more
> difficult to deal with.
>
> I have made my concerns to the builder and HOPEFULLY we can sure things
> up
> using the braces and brackets that you all have suggested at this stage
> you can push
> the top of the post and move it very easily about an inch or more.
>
> I appreciate the group's inputs very much. Since were potentially
> dealing with a safety hazzard
> here as a apposed to something in your backyard that maybe doesn't look
> perferct or isn't
> built totally correct, but poses no harm ... like a bar for example.
>
> Thanks ALL!!!
>

[ktro...@hotmail.com]

Great suggestions, i feeling better about the situation now... knowing
that we can add the supporting hardware at the end. That was my main
concern with just adding more wieght to the top before dealing with
this. The roof will have concrete tiles so there will be quite a bit
of wieght up there.

After talking with the builder he didn't think there was a problem, so
it was good that i brought it to his attention, since they weren't
planning on adding any additional bracing/support.

Thanks ALL!! I let you know the final result.

[zenboom]

nailed connections ?!
replace those nails with bolts and washers [ pairs at 90deg for each post,
if possible]
and tighten well. better yet, put in those 'knee' bracings suggested
elswhere...

--
R'zenboom

<ktro...@hotmail.com> wrote in message
news:1144131468.4...@i39g2000cwa.googlegroups.com...

[jbx...@gmail.com]

I happened to have a very similar problem! I built a 10x10' gazebo.
The base legs and floor are on 4x4s attached to standard concrete posts
set in sloping ground. The base and floor are solid as a rock since it
is bolted to the rim joist a pre-existing deck.

The problem are the 4x4 wall legs and roof structure. The entire
structure "stands" on the floor. I lag-bolted the wall legs at an
angle thru the floor and into the base legs and joists. But if you grab
a wall leg and shake it, you can set up a wobble. I was worried the
entire structure would come down in a thunderstorm. The problem is
finding structural stability with a something that large and tall
standing on "spindly" legs.

I attached metal 1x8 tie brackets on the headers (horizontal 2x4s
running between wall posts). They are angle bent and nailed in at the
corners on the outside. This helped alot but it still sways abit.

Other than using triangulating guy-wires to the house and some 50'
trees somewhere, I'm not sure what else to do (except pray every time
there is a T-storm!)

--JB

[Bob Morrison]

In a previous post jbx...@gmail.com wrote...

> I attached metal 1x8 tie brackets on the headers (horizontal 2x4s
> running between wall posts). They are angle bent and nailed in at the
> corners on the outside. This helped alot but it still sways abit.
>

You need knee braces at the upper corners as several posters have
indicated with pictures.

[cowgir...@gmail.com]

Don't use regular tin, try PVC tin; much lighter weight