What does your contract say? It all depends really on what your contract says...

The only thing the contract states is in the event of hitting rock, I am responsible for the cost per day of excavation plus extra materials. When I first reviewed the contract, I read this to mean any extra materials for excavation. I now realize that this could be read to mean extra gunite (and anything else for that matter). However, I am trying to find a reasonable explanation for why they would have needed additional gunite whether I had rock or not.

Oh I guess I assumed the gunite people and excavation people were the same people. I can't see either how extra gunite would be required. Did they have to take out extra material to remove the rock and now they have to backfill it will extra gunite?

It was shale which breaks apart. It seems they only took what they needed. When I came home after the rock breaker was there, my pool was dug and filled with the aggregate. It doesn't make any sense to me.

Yeh sounds like they are just trying to get in the chow line because they saw an opportunity. Unless perhaps they are charging you for the aggregate as a back fill. What do they say?

I left a message and am waiting to hear back from them. I would have thought it coulda been the aggregate (except the price was way higher). Also, it specifically mentions it is for the gunite phase. Since the excavator put the aggregate in, it can't be for that.

Gunite is usually priced on the linear foot, depth and thickness. Unless one of those changed, you might be getting a ticket to ride.

Good to know...thanks for the tip.

Rockadile-

I build in Austin, and deal with rock everyday. The extra charge should be labeled as "overbreak" meaning that when you excavate rock, or shale, you have a very uneven surface. Gunite applied under pressure fills any and all gaps in the walls. IF excavation was kept tight, shouldn't have the need to "backfill", and charges shouldn't be more than a couple yds. or so. That is unless you're building big and deep.I would imagine the biggest expense happened when they attached the ram and started chipping the shale.

Your builder putting aggregate in the belly is the right way to go!

LPG

I used to run into a lot of rock situations when I lived in Southern Ca. When you are dealing with rock, just as local pool guy stated you are left with big holes in the excavated pool area causing the gunite bill to even double at times. In most cases the gunite crew will hang buttonboard or sheet rock to make an attempt to fill the void without having to fill it all with gunite. I am not making excuses for your pool builder. When they hit rock during the excavation they should have told you all the implications to you financially before they continued on.

Gunite in so cal is charged by the ton. Currently about $115/ton. If a pool is overdug or removal of rock creates a void below the normal depth of the gunite shoot, you will pay for the added material. While they do add sheetrock to back up the walls, I've never seen it on the floor. I'd rather have a firm foundation on the floor instead of a hole filled with stone.

That's just it, there didn't look like anything out of the ordinary. The aggregate covered the vast majority of what was broken up and dug. There was no rock on the sides of the pool. And if there was I can't see how it would be enough to cost $2000+ of extra gunite. My pool is not that large and this happened only in the deep end which makes up at most 1/4 of my pool.