The purpose of this layer is to prevent any sharp stones from the Hard-core piercing the Damp proof Membrane and therefore reducing its waterproof abilities. If done properly it really is a solid area from which to go on to the next level. We then barrowed in the second 75mm and compacted again. I hired a Whacker plate for this job as I wanted to make sure it was a solid as possible. Once all pegged out, we barrowed in the hard-core to a level of 75mm and used a Whacker plate to compact it. I actually ended up taking these out when I was compacting but it was useful to get a rough idea of levels. Like we did with the Oil Tank, base I pegged out ground in order to establish the level for the Hardcore. Just trying to use a spade alone in these conditions is incredibly difficult.Īfter a long day of digging, we were down to our required level of 400mm below the top of the first course of blocks. They are so useful to break up dense and compact soil so you shovel it out.
![oversite or oversight oversite or oversight](https://www.peopleintelligence.com.au/media/1393/projectmanagement.jpg)
In times like this I cant recommend highly enough buying a Mattock. Firstly it was a boiling hot day and we were getting constantly eaten by horseflies but chiefly because, as all the work had been going on, this area had become really compacted and so was tricky to dig. As with the foundations it was time to dig(again)ĭigging the oversite was actually more difficult than digging the foundations even though we weren’t going half as deep. This would then bring our oversite perfectly up to match the floor level of the main house which in turn meant when we knocked through we would have a seamless transition into the extension with no nasty step ups or step downs to deal with. Taking all of those measurements into consideration, it meant we had to dig down 400mm from the top of our first course of blocks. 50mm layer of builders sand (blinding layer).With that in mind it was a case of working out how far down we had to dig.
![oversite or oversight oversite or oversight](https://aperionglobalinstitute.com/wp-content/uploads/2018/01/Risk-Management.jpg)
This would be where the top of our concrete slab would finish. Previously we had built up to DPC which meant that we had already established our floor height. To simplify the process it is very similar in preparation to laying a concrete slab for a shed or preparing to lay a patio but obviously with some unique adaptations. It also serves a second purpose in helping to insulate the build but more on that later. Like everything it is a very important step as it is what you will be essentially walking on when the extension is built. In building terms the “Oversite” refers to a layer of concrete that is used to seal the earth and create the ground floor of your house.