# Anchor a gazebo without drilling into concrete



## diynonstop (Jun 11, 2014)

We have a 10x12 canvas top gazebo with a steel frame. My husband refuses to drill into the newly pour concrete slab. 
I was thinking we could anchor it down by using 35 pound concrete planters filled with play sand and river rock, and topping it with 3 inch think flagstone pieces.  Maybe even put sand inside the bottom 1/3 of the hollow gazebo legs.  This would probably bring the weigh to around 100 pounds per leg. Felt confident this would work.  But  Last night it stormed and I heard the wind ripping across the house.  Maybe 30 mph winds.  I fear 100 pounds per leg wouldnt be enough. Neighbor has the same one bolted down to concrete and it was fine.   Cant make a mistake because if this thing breaks free it will end up in the pool tearing the new pool liner $$$$.  
How much weight would be enough?  Other ideas on how to weigh it down?


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## bud16415 (Jun 11, 2014)

With a 30 MPH wind the wind force per sq foot would be about 2.3 pounds x 120 = 276 / 4 legs = 69 pounds per pot.


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## Wuzzat? (Jun 11, 2014)

diynonstop said:


> . . .refuses to drill into the newly pour concrete slab.
> 
> if this thing breaks free it will end up in the pool tearing the new pool liner $$$$.



"The assumption is that the greater the number of ideas generated, the greater the chance of producing a radical and effective solution."

Run two galv. steel cables under the slab using a >12' pole/pipe from HD and strap the thing down.  Then clean and return the pole.
If you use a pipe you can force water into it so it digs its own path.  If you hammer it in you may need a comealong to extract it.

2nd option, anchor a cable with a strong spring to something else with the cable too short to allow the tearing.  Bury the cable so it's not ugly. 
This is what we do with beach umbrellas and a screw in dog anchor so nobody gets impaled by our umbrella.

BTW, your  is killing me.


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## kok328 (Jun 11, 2014)

Fill a 5 gallon bucket with mixed concrete and set the leg of the structure in the concrete.  Form it up to maintain plumb on the leg while it sets up.  Repeat for the other 3 legs and decorate as desired.  You can leave the pour in the bucket or break away the bucket to reveal the concrete base.  :2cents:


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## nealtw (Jun 11, 2014)

bud16415 said:


> With a 30 MPH wind the wind force per sq foot would be about 2.3 pounds x 120 = 276 / 4 legs = 69 pounds per pot.



Bud; you also have to figure in lift as the wind will hit just right sooner or later.


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## havasu (Jun 11, 2014)

bud16415 said:


> With a 30 MPH wind the wind force per sq foot would be about 2.3 pounds x 120 = 276 / 4 legs = 69 pounds per pot.



Bud, your reply astounded me. : How did you come up with the wind force per square foot? Is there a formula?


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## oldognewtrick (Jun 11, 2014)

havasu said:


> Bud, your reply astounded me. : How did you come up with the wind force per square foot? Is there a formula?



It's the formula of the first rule of salesmanship...IF YOU CAN"T CONVINCE THEM, CONFUSE THEM...:


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## bud16415 (Jun 11, 2014)

On iPhone now but will give explanation later. Took into account up flow as used total area in calculation, worst case. 

Correct if you can't dazzle with brilliance baffle with BS. 


Sent from my iPhone using Home Repair


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## nealtw (Jun 11, 2014)

http://www.wikihow.com/Calculate-Wind-Load


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## bud16415 (Jun 11, 2014)

Wuz you are the dirty dog that filled my new water pipe with dirt that time. Glad I switched to PEX. 


Sent from my iPhone using Home Repair


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## Wuzzat? (Jun 11, 2014)

kok328 said:


> Fill a 5 gallon bucket with mixed concrete and set the leg of the structure in the concrete.


100 lbs each.  
Iron is 3x the density of concrete so maybe add some scrap iron to this bucket.



bud16415 said:


> the dirty dog


Nobody says that any more.:2cents:


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## bud16415 (Jun 11, 2014)

http://www.bristolite.com/interfaces/psi_wind.aspx

Here is a good explanation of the formula I used.

Sorry Wuz for calling you a dirty dog I didn't know that was no longer in the vernacular. I'm never PC about these things.  


Sent from my iPhone using Home Repair


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## Wuzzat? (Jun 11, 2014)

bud16415 said:


> http://www.bristolite.com/interfaces/psi_wind.aspx
> 
> Here is a good explanation of the formula I used.
> 
> ...


You could use 'filthy cur' but nobody would know what you're saying. 
A modern curse word has to do with having carnal knowledge of a close female relative at least 10 or 20 years older than you.


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## slownsteady (Jun 12, 2014)

If you do the concrete buckets, you'll have to figure out where/how to store them in the off-season, and assembling the tent in the spring (assuming that this a seasonal set-up) will be a bear. Does your  gazebo have a place for tie-downs? You can use guy lines that anchor to pegs beyond the concrete slab. These could be used only when winds are expected.

Another option is the use of weighted plastic sleeves that the pole (leg) slips though. You can find these online, but I don't have a brand name for you. I use old plastic-coated weights from a gym set. About 30 lbs each - 1 weight per leg.


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## bud16415 (Jun 12, 2014)

After reading all these ideas I bet he changes his mind and drills the pad.


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## Wuzzat? (Jun 12, 2014)

bud16415 said:


> After reading all these ideas I bet he changes his mind and drills the pad.


That's the OP's option.  We've done our job.


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## nealtw (Jun 12, 2014)

Depending on how big the slab is, perhaps anchers could be attached to the edge of the concrete for tile down strap or something.


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## Wuzzat? (Jun 12, 2014)

Or four of these
http://www.google.com/search?q=c+cl...F%2Fwww.justclamps.com%2Fc_clamps.htm;200;200

The OP's husband could also rent a gun that drives fasteners into concrete using cartridges.  No drilling, but way more dangerous than the other options, I think.


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## diynonstop (Jun 12, 2014)

bud16415 said:


> With a 30 MPH wind the wind force per sq foot would be about 2.3 pounds x 120 = 276 / 4 legs = 69 pounds per pot.



I used the link to the formula and came up with 
Area 120 x Wind Pressure 2.304 x drag 2.0= 552.96 / 4 legs =138.24 pounds per leg... not including uplift and wind vibration.

Now, I am absolutely convinced that he must drill into the concrete and put those 4 bolts per leg into that beautiful concrete. 138 pounds is like having a grown up sit on each leg and hold it down. 

I will use our small pop up tent to figure out the exact location for the permanent one. That way we wont make any mistakes on drill spots of the 10X12 gazebo. 
Thanks for your help, I am completely freaked out.


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## diynonstop (Jun 12, 2014)

BTW after looking closer at the gazebo roof does have a vent.  Not sure how well it works, but that would help relieve the pressure.  Plus the canvas roof does come off.  I (he) could take the canvas in down in the winter and just leave the frame up. 
 Either way roof on or not, It needs drilled down and attached to the huge pretty new concrete pad.

 Hubby just needs to cave in and let me win this one.


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## bud16415 (Jun 13, 2014)

I was sitting at a light this morning next to a convenience store and they rent a corner of the parking lot to a farmer during the summer for a farmers market. Yesterday I saw them setting up their framework today they had the canvas cover on. My guess is the tent thing is 16 x 24 and the store must have rules about driving anchors into the parking lot. They have 6 round poured concrete things with eye hooks in the top and straps going to the corners and midway the long side. I was going to take a picture as the light changed but ran out of time. These hold down blocks were 3 foot in diameter and 3 foot tall. I have no idea how they figured that out. But they were not taking any chances.


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## slownsteady (Jun 13, 2014)

Question for the OP: are we talking about a 2 or 3 season garden gazebo (a.k.a. tent) or something more permanent like one of those garage structures?


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## nealtw (Jun 13, 2014)

bud16415 said:


> I was sitting at a light this morning next to a convenience store and they rent a corner of the parking lot to a farmer during the summer for a farmers market. Yesterday I saw them setting up their framework today they had the canvas cover on. My guess is the tent thing is 16 x 24 and the store must have rules about driving anchors into the parking lot. They have 6 round poured concrete things with eye hooks in the top and straps going to the corners and midway the long side. I was going to take a picture as the light changed but ran out of time. These hold down blocks were 3 foot in diameter and 3 foot tall. I have no idea how they figured that out. But they were not taking any chances.



This is what happens when the insurance company requests an engineers report.
If a typical leg as four holes for bolts, he might figure the tensile strength of those bolts and figure that is the min. required and go up from there. He is responsible for thirty years so he will make sure if there is a failure it won't be his.


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## bud16415 (Jun 13, 2014)

nealtw said:


> This is what happens when the insurance company requests an engineers report.
> If a typical leg as four holes for bolts, he might figure the tensile strength of those bolts and figure that is the min. required and go up from there. He is responsible for thirty years so he will make sure if there is a failure it won't be his.


 

I figured the engineer did that and came up with a 1.5 dia x 1.5 height block and said you need 3 of them. It then was passed on to the lawyer for approval and he said we better double the weight so he said make them 3 dia x 3 high  and make 6 of them.   :help:


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## nealtw (Jun 13, 2014)

Or someone just found a bargain on some chunks of concrete.


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## Wuzzat? (Jun 13, 2014)

Look for what other gazebo makers recommend for anchoring.


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## diynonstop (Jun 13, 2014)

slownsteady said:


> Question for the OP: are we talking about a 2 or 3 season garden gazebo (a.k.a. tent) or something more permanent like one of those garage structures?



This is the Gazebo. Its from Lowes. Steel frame with 3 inch square legs.  Its not meant to be a permanent structure, but most people bolt it down and leave it up all year.  I've seen some around here where they take the canvas roof off in the winter.


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## Wuzzat? (Jun 13, 2014)

"wind speeds up to 27 metres per second *[~60 MPH]*" but this is for a wooden Gazebo:"
so yours can withstand much less.


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## slownsteady (Jun 14, 2014)

I think you're worrying too much.  Unless you live in a tornado alley. Just make sure to close the curtains so the wind can't get under it.

And maybe get some big planters (pots) at the four corners. Grow something nice in them and utilize the weight.


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## oldognewtrick (Jun 14, 2014)

I think I would leave the curtains open in the event of a storm. Wind getting under the bottoms would have a lot more sail area with them closed. 

I do like the idea of planters at each corner though.


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## slownsteady (Jun 14, 2014)

My gazebo mentioned to keep the curtains closed right in the instructions. Much less air will get under.

Here's a new thought, but not a perfect solution. An anchor for a pool cover is drilled into the concrete with no problems. The good thing about them is that the anchor recedes into the hole when not being used and that covers the hole and prevents water damage. Problem is that they are designed for lateral strength - not the vertical lift that a tent might apply. But some variation on the theme seems like a good idea.

http://www.google.com/search?q=pool...NIsTgsATQ1YCoAg&ved=0CEUQsAQ&biw=1500&bih=899


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## diynonstop (Jul 17, 2014)

Thanks for the advice! So I ended up letting him have his way. We used HEAVY concrete planters, filled with concrete and topped with river rock. Guessing around 150 pounds on each leg. It stormed the other day - Super storm winds and rain from every direction and hail... I ran out and closed the curtains on the gazebo. With the curtains closed it held. With the curtains open, I believe it would have moved. 
 All I got to say is, I will never leave the house and forget to zip up that gazebo. It won't be my fault if it moves.
 Heres a picture.


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## slownsteady (Jul 17, 2014)

I'm glad you didn't drill the holes. Most of the tents on the market won't last long. And then next year you try a different design or manufacturer and the holes don't line up.


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## Wuzzat? (Jul 18, 2014)

And using 20 gallon containers filled with water would make the setup even more versatile.


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