Need gravel advice for overdug "Dig, Refill, Redig" Rock Excavation Method

Hojo76

Silver Supporter
Jun 20, 2016
48
Central Arkansas
I need recommendations for the TYPE OF GRAVEL or fill needed to replace overdig due to massive rock excavation. Planning to concrete hopper and slopes in deep end but do not want to use concrete for all voids because there is just too much needed. I understand that this is not ideal. However after dealing with 5 feet deep of solid bedrock for the last 8 months, it is where we are at. Thank you in advance for your advice.

16x36 steel wall vinyl pool 8' deep
 

jimmythegreek

TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
1,341
Morris Cnty NJ
1" to 3/4 material that's clean gravel is good. If you have any water issues in ground put a drain line in back to pad water will collect in the gravel. I had similar issues just dry mix the concrete right in the pool and flick it on. Get the bottom 6" away from finished hopper height and form and pour it. Then work on walls with dry mix and build them out. 50 pound bags are easier to handle getting into the pool. Mix right on the hopper slab with a hose folding over just damp and apply. I would vermiculite over walls leave hopper floor concrete
 

ckwinters

Well-known member
May 29, 2018
57
Carlisle, PA
Just want say glad to hear the project is moving! I remember the post last year when you hit rock! I felt bad for you on that...encouraging part is that the dig is the worst part of diy in my opinion! It seemed like the mud would never end. Once you start assembling walls and doing plumbing it really begins feeling like progress 😁
 

Hojo76

Silver Supporter
Jun 20, 2016
48
Central Arkansas
Thank y'all for the advice. We poured footers at all wall joints, stacked concrete blocks and core poured blocks reinforced with rebar. We are taking jimmythegreek's advice from last year to form up hopper and slopes and pour all of that with the bond beam. We were just hoping to fill in some of the voids with gravel under all that concrete. It will be very similar to "Kfkruse- Help. Plastics soil overdig" post. Im attaching a pic from a couple of weeks ago. The blocks laying around the deep end are just there to hold back some of the dirt and rocks that wash in when it rains (which has been pretty much the past six months straight.) Luckily, water is not an issue and is being rerouted, so we only really have to deal with water that falls in the pool and what seeps out of the sandy dirt in the pool.

Thanks again. It has been very frustrating between the rock and monsoon season, but we are full steam ahead now! IMG_0675.JPG
 

jimmythegreek

TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
1,341
Morris Cnty NJ
Wow that's a real mess they left you. Hard to judge from pics but I would probably make braces like you have and brace the pool heavily high and low at all the joints and then use plywood to extend the walls down to the dirt. Pour the collar and let the walls transition to concrete down to earth. This will lock pool walls in place and then you can work on the hopper and pool floor. Theres too much missing material IMO to form the walls and do the whole pour with hopper all at once. Remember if anything moves during the pour, concrete waits for nobody. You gotta weigh the risk to reward. Hang some rebar bent in an L in the bottom holes of panels to help lock it in place tieing it back into the collar. Once you get that stabilized with the collar in place it will be much easier to work with the rest of the pool. Just be sure to shim and tweak panels to plumb and level
 
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SBall

Well-known member
Jun 27, 2017
248
Nashville, TN
I agree with Jimmy. Use plywood to to extend the walls down to dirt, and then use the 2x4s to brace across the pool on the plywood sections, so that when you pour the concrete, it doesnt just push the plywood over, and otherwise brace the plywood as best you can. Once that is done, I would then focus on the hopper, build it up using 3/4" gravel, and then pour the hopper pad.

Once that is all wrapped up, more gravel to grade the entire bottom of the pool...all the slopes, the shallow to deep transition, etc, leaving yourself roughly an inch for the vermiculite or grout floor.

BTW, 3/4" gravel is really challenging to move with a shovel, but 1/2" is pretty darn easy, so depending on what types of equipment you have and how you are going to stage this, you may end up with both sizes. I graded the entire floor of my pool and backfilled with 1/2" clean gravel. But you have a ton to actually fill, which is where the 3/4" will come in handy.