Securing a 9ft kids slide in the garden

[chaoticj]

Hi,

We recently bought a 9ft kids slide from a well known catalogue/store retailer to be used in our garden.

The instructions advise to dig two 35 x 35cm holes, fill them with concrete and fix the slide to them with plugs and screws.

An alternative slide which was 10ft from another well known retailer of childrens toys is supplied with ground pegs.

I'm just wondering what the recommended way of securing a slide is, I can use the first method but it means we won't really be moving the slide from wherever it's placed but then again, I wouldn't want the slide to try and blow away or potentially tip over..

Thank you in advance.

 

[Tigercubrider]

If it was me I'd go for the concrete option
But level the concrete below grass level so it can be covered later, and add packing to help level it

 

[chaoticj]

Thanks Tigercubrider, good idea. I have a bag of cement but after googling apparently this isn't concrete, it's just a component of concrete.

What would be best to use? Blue circle postcrete? How much would I need about a 20kg bag?

What would you use to pack under the slide with? Thanks in advance!

 

[endecotp]

What would be best to use? Blue circle postcrete? How much would I need about a 20kg bag?

Edit: I’m double checking my sums.....

Places like Wickes an B&Q have various kinds of readymixed concrete which vary mostly in how quickly they set. Go for a slow one so you can relax.

 

[endecotp]

OK, here’s the maths done right this time, I hope no-one saw the first attempt!

35cm cube of concrete, right?
0.35 x 0.35 x 0.35m = 0.043 cubic m.
Density of concrete = 2400 kg/m3.
So weight of concrete needed = 0.043 x 2400 = 100 kg
That requires a bit less than 100 kg of dry readymix because of the water that you add, but not much.
So five 20kg bags per hole.

(Sanity check: imagine a large child throwing themsleves around at the top of the slide; would a 100 kg adult standing each side of the base be enough to hold the slide down? Yes, I think so. So 100 kg of concrete would work too. But it’s assuming that the concrete is a dead weight; if the concrete “glues” the slide to the ground you would need less. So perhaps they are being a bit pessimistic.)

 

[Tigercubrider]

I have only built pergolas and fences with postcrete, but keep the hole small and tight by using a post hole digger (£25) and the ground will hold the posts tight, the concrete packing the hole.
Height wise, just something like a nylon bread board as packing would allow the concrete to be slightly below the grass, so you can later hide the concrete in situ.

 

[chaoticj]

I have only built pergolas and fences with postcrete, but keep the hole small and tight by using a post hole digger (£25) and the ground will hold the posts tight, the concrete packing the hole.
Height wise, just something like a nylon bread board as packing would allow the concrete to be slightly below the grass, so you can later hide the concrete in situ.

With the winter weather etc. I haven't yet done this.. I have everything I need but plastic breadboard, folk round here don't know what that is.

Could I make the holes, fill with concrete leaving a gap between the concrete and top of the soil then place some sort of pressure treated plank to level the surface then fix slide through wood into concrete?

 

[cwhaley]

Best bet is to pour the concrete and set threaded rods (available at many places) into the concrete. These can then go through the feet of the slide with nuts holding it all down to the rods you set. I'd use a mix of cement and ballast (as opposed to sand) as recommended to me on here before.

As for leveling it just use an old piece of ply or MDF. This can also be used to hold the threaded rods/bolts while the concrete sets.

 

[chaoticj]

Great idea cwhaley, would you use zinc plated or stainless steel threaded bar?

 

[Nozzle]

Use a bag of postcrete for each leg (pre-mixed and very fast to set)

Nozzle

 

[cwhaley]

Great idea cwhaley, would you use zinc plated or stainless steel threaded bar?

I used zinc-plated bar as this is what I had to hand at the time. As long as you don't leave any cut ends exposed it won't corrode.

 

[mattylad]

You could bury the concrete several inches below the surface with some of these long eye bolts inserted in (with plates to enable a secure fixing) which you can then tie the slide down onto while also covering the concrete in a few inches of turf etc. much less likely to cause injury when fallen onto.