Excavating for your Pool

What sort and size of excavator?

The first question that arises is what machinery shall I use and more importantly can I drive the digger myself?

Let’s take the machinery issue first. The best machine for most pools will be a 2.7 tonne rubber tracked 360 degree excavator. This will dig most pools up to a 12 x 6 metre pool with ease. However if most of the pool arisings need to be moved more than about 10 metres or so it will be better to get some other equipment as well - like a tractor and tipping trailer to load the arisings into for tipping at the right spot.

Backhoe type rubber tired machines like JCB’s, as they are known in Britain, are too big for most gardens and the smaller tracked machines are much safer. But – do not use a machine smaller than 2 tonnes because they are inherently unstable and it is too easy to turn them over.

Should you drive it yourself?

My advice is – do not even try!

It is quite easy to sit on a digger and shift some dirt. However the whole process becomes quite complex when you know where you want to put the soil but the digger is too small to do it in one operation. It may require perhaps double and even treble handling across areas that also need digging – so what is the best way to do it to minimize the time taken? I have dug about 40 pools – and I still make the occasional mistake.

I absolutely guarantee that if you have never done this before it will take 3 x times as long just because you dig the pool in the wrong sequence. Your lack of driving skill will just waste even more of the machine time that you are paying for.

Believe me you will be pretty busy if you just watch a skilled operator to make sure that he does not waste any time and that he is doing what you want him to. And if there are any substantial level changes on the site do even think about driving the digger – this magnifies the problem by a factor of 4 and is much more dangerous than working on a level site.

You need to take some special precautions if there are a lot of rocks in the subsoil as these will always work their way to the surface and wreck your mower if they are not buried deep enough. So when you have rocks the subsoil needs to be divided into two heaps of large rocks and small rocks plus sub-soil. The large rocks are anything above 150mm in any direction as rocks smaller than this should not wreck the mower. Be warned – this will have to be done by hand unless you can hire a rake attachment for your digger!

When they are separated out the rocks need to be buried first so that they are deepest. This will massively increase the time that it will take for them to work their way up to the surface – as they always do eventually – but if they are deep enough this may take hundreds of years!

Carting the arisings off- site?

It is possible to dig the pool and load the arisings straight into a tipper to take it all off site and sometimes this is the only way to do it on a small and restricted site. If the tipping site is a long way away, resulting in a long wait before the tipper returns for the next load it may also be better to dig and load like this – especially if double handling to get the material to the load-out stockpile is needed.

But it is often the case that the spoil can only be easily loaded from a specific location simply because the access is restricted or the garden is too soft for a tipper to cross it.

So in most cases, especially if the receiving site is quite close, we find that it is easier and cheaper to dig the pool and stockpile the arisings. Then a tipper lorry is hired for one day and the digger is used continuously just to load out from the stockpile until it has all gone.


The cost of disposal off-site

In the Uk the cost of tipping excavation arisings can be cery costly - and can be as high as £25 per ton - without the actual loading and cart costs.


So a 10 x 5 x 1.5 m pool that could generate 160 tons of arisings could involve total load,cart and tip costs of £6000 plus any VAT.