Day 7
The dig got done yesterday! It went kinda sorta as planned... Lol
Here's the recap. (most of this has already been posted in pieces above) I have a 3'+ drop from corner to corner. My plan was to raise half of the site by 17" and cut into the other half dropping it and adding a far side retaining wall. I set my laser level at 110" (17" + 4" for cantilevered decking + 42" for the walls + 47" for the height of the level) and started digging. Every time I walked off he dug too deep so I ended up sitting and watching everything he did. Once we got deep it turned out to be all clay. My plan had been to use the fill dirt to raise the grade but I'd read that clay is expansive and shouldn't be used for back fill. Since he'd already been digging too deep and I didn't want to pay for gravel to raise the grade, I decided to reset the elevation on the low corner. For some stupid reason I just subtracted 17" and started digging. That made me 4" too deep everywhere... That plus his desire to hit the earth's core made me as much as 12" too deep in some spots. I debated dropping the surrounding elevation or raising the bottom with gravel or raising the bottom with clay anyway. It turns out that the expansive clay issue is only an issue if you're above the frost line! Since I'm below the frost line, I raised the bottom with the clay. He couldn't get me graded within the tolerance I'd like to see so I'm ordering some gravel anyway. I'm doing a 6' constant slop bottom. No diving board but plenty of room for the grownups and volleyball. I'll add a 3' bolder on my deck to do cannon balls from. The deep end dig went well. I put the end wall up and then dropped 2 pins 3' in from the back and sides. That's the corners of the deep end. I pulled sting between the two and also from the pins to the transition line. (22' long and flared out to meet the walls). I set me level for a 6'2" depth and let him start. We established a slope that felt right and then peeled a few inches at a time off until he hit the depth. I decided to knock the sides off by hand later. I didn't like how crumbly the top soil looked and feared that they'd end up deep under the walls. That would mean forms before I could pour the collar...
I ended up paying him $2,500. I didn't get as many quotes as I should have but it seems fair. I also had him clear out a fence line in the front to make room for the concrete truck and grade all over my yard with the fill dirt. I think he mostly got the grading right for water drainage. There's one area that I might need built up some.
Things I learned about excavation
- Excavators like to dig. If they have little/no inground pool digging experience they don't appreciate the importance of hitting their depth marks.
- Grade the site and then dig. He had a lot of trouble working around the edge of the pool to get the surrounding elevation low on the high side.
- Honestly it might be best to figure #57 (3/4) clean gravel into you budget anyway, I've been reading about guys that use the gravel on the bottom to make things "perfect" and even using pea gravel to fine tune the walls. I'll start on my walls soon and I think it'll make life much easier to have that "perfect" base to work on.
- Pull string to mark your overdig. I used paint and had PERFECT lines drawn. They were trampled and covered with dirt quickly...
- Don't ask your excavator if he can dig a pool. He'll say yes. Ask how many pools they've dug in the last year. That's a more direct question that requires a more direct answer.
- You can make a BUNCH of dirt disappear in your woods. I'd planned on having it dumped on my neighbors land. He's a farmer and says he always need fill dirt for wash outs. The excavator didn't like the rough dirt road he had to drive down. Said it took too long to navigate. He talked me into letting him spread it in my woods. He cleared the honey suckle and fallen Ash trees out of a large area and shaped the fill dirt in. Looks much better!
- Just a random interesting note. He had a ramp in the corner that he used to get the skid steer in and out. Everyone that stopped by couldn't figure out how he was going to get the ramp out of the hole without getting stuck in the hole! He ended up digging the ramp back until it was outside of the walls of the hole. That gives me a way to get in and out and also leaves me room in the over dig to work on plumbing. I'll back fill with dirt/gravel and bury under my deck later.
GAS PROBLEM - The gas guy just came out to mark a gas line that he missed on his last trip. We got to talking about my pool heater and I've got an issue... Whoever installed the underground propane tank used regulators with 1M BTU capacity but only used 3/8" pipe... According to him, 30' of 3/8" pipe will only push 299k BTU... My heater is 400k BTU. He says it won't turn on at all if the pressure is too low. He'll get back to me later today with a quote to upgrade the pipe to 5/8".
GRAVEL - Just ordered 60 tons of #57. I called about 10 gravel yards and found one at $14/ton. Prices ranged from $14-28. 2nd cheapest was $15.50 and most were around $20. This place is $84 delivery per load. 20 tons per load so 3 trips total. I'm hoping this will be enough to flatten out the bottom and back fill behind the walls. They'll get one load to me tomorrow so I can get the bottom done and walls up. (I should have ordered this a few days ago so I'm not down today...)
CONCRETE - I'll order this when I have some time this afternoon.
Here's a final pic of the hole.