Bags of 20Kg Concrete for a base of a Mega Tree

[damona]

VOTE VOTE VOTE VOTE VOTE VOTE what you used for the base

Hi everyone. I thought we would collect an interesting statistic. In January 2015 I made a base for the MegaTree in the ground. Mine is a dual socket system. i.e Two sockets in concrete, insert two 1.8m steel polls, between the two polls at surface level on top of the concrete a 6m aluminium poll. The 6m poll is clamped between the other two steal polls. It's a bit hard to judge how big you make the hole. I was lucky I used 4 reinforcing bars as part of the poor, so when I ran out of concrete bags I could push them in and have them stick out to join the conrete to I just poor to the concrete I would/had poor the next weekend. I did 14 bags one weekend followed by 4 bags the next weekend a total of 18 bages. I thought I would only use about 12 bags in total before I started I was very surprise at the after putting in 18 bags. I am in a very very windy area. I have a park opposite the house.
It's also design to be used as a normal flag poll, with out any guide wires when it just as a flag on it. The research I did indicate the dimensions required I did go over this as its got two sockets.

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| 6m alumin poll
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||| 1.8m steal polls
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| | about 80 cm in the ground, as far as I could reach down with my arm
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VOTE VOTE VOTE VOTE VOTE VOTE VOTE what you used for the base

 

[mborg10]

18 bags of concrete WOW! I have a 6m tall mega tree with a fibreglass centre pole and I used 2 bags of rapid set. Been holding strong for 3 years now

 

[bjpc2716]

8) my into 600mm hole 2 bags

 

[lizardking]

yeah 360 kgs + of concrete will hold it in lol i personally woundt think you would have needed that much but if its safe its safe

 

[AAH]

My mega tree is a boring old 6.5m fairy light tree. It sits over a bit of 1/2" rod purely to locate it and it is stayed in place by the fairy light strings. It has been in use for a number of years and I've never had it come down and never had a fairy light string break. It takes me longer to roll up the lights at the end of the season that it does to grab it out of the shed and erect it.

 

[mborg10]

The mass footing at the bottom is there to cater for the overturning moment at the base. Think of it as a counterweight and the pole is a giant lever. REO is not really required as the concrete is always in compression and the reo acts in tension. As far as the guy wires go, they are more required for the strength of the pole and stop it bending or snapping. Generally flag poles do not require guy wires as it offers very little area for it to add wind loading or weight. Strap a bunch of lights on especially pixels and you may find that guy wires will be required.

 

[andrewa]

My hole required 8 bags as my brother in law dug the hole way too deep

 

[Pircy]

I have done quite a bit of fence building. For a 6 foot fence with 90 x 90 fence posts, I only use 2 bags of 20kg rapid set per post. Bear in mind that a 6 foot wooden pailing fence bears a lot of weight and is effectively like a sail catching a lot of wind. The point being however, whenever you set any post in the ground, regardless of concrete used, the rule of thumb is to have 1/3 of the length below the ground. Guy ropes will further reduce any chances of a runaway mega tree!

 

[mararunr]

6 meter above ground, 32 strand, 360 tree - 1.2 meter below ground, 3 bags 20kg rapid set.

 

[scamper]

only a small 4.5m pole (above ground) for me and I used 3 bags and 700mm in the ground.
I don't have guy wires.

I will say however, it really depends on the soil type also.
If you are in sandy soil, then more concrete or depth is ideal.
In a rocky or clay soil you can get away with less.

 

[fasteddy]

I used 3 x 20kg bags of concrete in my hole which seemed more than enough for the job because if building a large tree then it will also be supported by the guy wires you use.
My tree was just over 7 metre tall and was a 12 strip tree

The reality is you could use a 40 gallon drum with some brakets made up and fill it with water and make it temporary, because as long as you use guy wire support with a heavy base then the whole tree will stay put.

 

[mangoat]

i could stand my then 16 month old kid inside the hole, and its from bottom to about 6" below grand level, filled with home made concrete.....

probably 3 good wheel barrow loads in there.

 

[Benslights]

coming from the building game and doing more foundations than I care to remember (specially as a apprentice and digging them by hand)

I made a hole 400 x 400 and 600 deep. I used general purpose concrete as it goes off better and is much stronger then quick set. in the centre I have a 90mm tube that the pole slides into and my tree does not move at all and does not need guy ropes.

I took just over 2 bags to fill

 

[damona]

Those who have not voted yet please do for MegaTrees new for 2016

 

[Kitman]

Dug a hole a little over a meter deep and sunk a 1 meter long piece of RHS in and then top it off with 2 bags of hi strength ready mix concrete, so far no issues has been up for 3 weeks solid as.