Installing the loops for the ground source heat pump is turning out to be a lot more labour intensive that we were expecting.
Rather than digging trenches, we have decided to take up all of the top soil and sub soil to a depth of about 1m. Digging 1 m deep trenches 1m wide and 1 meter apart is just to hard. It is easier to remove all fo the soil in one go rather than digging trenches. However, this approach has generated a lot of soil – and I mean a LOT! We have mountains of the stuff. We have even flattened the top of one of these mountains and are piling the soil on top.
The other problem that we have is that subsoil contains a lot of fractured stone. It doesn’t contain any clay. This means that we need to scrape the bottom and pack the subsoil down so that there is little chance of the pipework being damaged when they are laid. The ground is then “tracked” in. This means going backwards and forwards and using the tracks on the excavator to flatten the bottom. This also crushes a lot of the bigger stones. Since we have upgraded to a 14 tonne excavator, it really does crush the stones in the bottom.
All of this means that it is taking longer (and costing more) to install the ground loops. I am not sure that there is anything we could have done differently. But we probably could have plan and estimated the ground work a little more accurately. Clearly, the amount of effort involved in installing the ground loops will vary according to the quality of the ground. It would be wise to check this out before starting on work like this.
The other issue to consider is access – can you get machinery of the right size onto the site. Doing ground works on this scale requires big machines and getting them on site (or even to site) can be a challenge. If your contractor is hiring machinery, make sure that the hire company has looked at the routes to the site and agreed that the machine can be delivered. Then if there is an issue, this is down to the hire company and not you.
We have stripped the one half of the field and piled all the soil on the other half! We are now out of space!
We are starting to run out of space.
This is a 14 tonne excavator. We had to trade up from our 8 tonne excavator to try and speed things up. There is a lot of soil to move.
We are now starting to run out of space and are piling up the spoil.
