Does anyone know much about compaction reports?
Our block has a fair bit of fill and a bit of a slope too - soil test came back with a P classification. Before buying the block we spoke to the neighbours (whose blocks have a similar amount of fill) and we got a good idea of how much they'd had to spend on site works and slab. We were actually able to negotiate for the developer to do the site cut for us as part of the purchase price of the land which'll save $$. The builder doesn't normally allow it, but in this case they were happy because they know his work. The plan was to get the preliminary contract, do the site cut, do a secondary soil test to check that everything was good and nothing much had changed from the original soil test, and then get the contract finalised.
But in the prelim the site works/slab upgrade turned out to be a bunch more $$ than we were expecting - about double that of either of our neighbours (one of whom has been using the same builder). We were told that the soil report was a bit surprising and that perhaps the tester was just a bit over-zealous. They said that if a compaction report was available and the fill was nice and stable, then that could drop the slap upgrade cost by a couple $K. When the developer was approached about a compaction report apparently he said there was no point in getting one done before the site cut because that'd change everything.
We've now been told that a secondary soil test is probably unnecessary and that slab costs won't change. I don't understand why the story has changed but I suspect that the people making the decisions haven't invested any time in looking at our situation. I'd like to find out a bit more about what a compaction report might show up and whether anyone thinks there is a possibility that, once the site cut is done, a soil test would lead engineers to rethink the preliminary plans, and maybe even reduce costs. Any ideas???
We just don't want to have to pay for unnecessary slab costs.