Build a DIY Plunge Pool

jimmythegreek said:

No way on a structural pour. I can mix a pallet in no time with a 2 bag mixer. You can't control the water mix in a tarp. Read about water and concrete and what happens to wet mixes

Click to expand...

Okay, concrete question, and a couple of updates.

I got my Hayward drains, which I'm putting together now. I'm using 1.5" plumbing on a .5hp pump, as it's a small pool. The way the drains are designed, the middle of horizontally laid drain pipe is exactly 3" below the finished surface of the pool floor. I'm pouring a 6" thick concrete floor. The question is, do I put the rebar above or below the horizontally laid drain pipe?

I had originally bought 3" dobies to position the rebar, but that will put it at exactly center of the horizontal drain pipe. Doing some reading online, I saw several discussions about putting the rebar in the top 1/3 of the concrete to prevent cracking, but in the bottom 1/3 to increase structural load capacity. My rough calculation is the filled pool will weigh about 15,000 pounds, plus or minus 1,000 pounds. I'm assuming that means placing the rebar above the pipe is correct?

Update: Here's how I worked out my drainage issue.

So I dug this 7-foot deep hole into a hillside, where there's a mix of stone, clay and dirt. The hills here can slide if they get saturated, so I wanted to ensure good drainage. I bored a drain hole through the hillside to the downward slope, then put a French drain around the perimeter of the hole and in-filled with gravel--the concrete will end where the gravel meets the drain pipe, and I'll backfill the bottom of the hole with gravel after the walls are finished.

I also wanted to have a drain out for the pool. Originally, I planned to put a "t" in the pool drain to a valve where I could just open the valve to drain the pool. An engineer I respect a lot convinced me to keep it simple and not build in a way for the pool to drain on its own. So instead I installed a gravity drain into the outlet of the French drain. It will extend up to the level of the surface, and will be entirely outside the pool walls. I can then just drop a garden hose into the drain and siphon the pool dry if I want, or I can put a valve in the pump return pipe to use the pool pump to drain into the gravity drain. It'll all go into the main drain and down my driveway to the storm sewer.

Here's where I'm at. I've got 1.5" drain pipe, sitting 1.5" off the gravel. The rebar is raised 4" off the floor, just over the drain pipe. The total thickness of the slab will be 6". The rebar is continuous through the floor and into the walls, so eliminating it is not ideal at this point. Seems like every video and image I see shows pools with both rebar and pvc drain piping working together. What am I missing? Thanks for the help.

I haven't posted in awhile, but I've made progress on my hillside plunge pool. Over the big hurdle of pouring the foundation and setting the first row in place, and now have a couple of follow-on questions:

This is where I'm at now. I've poured a 7-inch foundation, sitting on top of 3 inches of gravel with a 3-inch french drain all around the perimeter, and augured a drain pipe through the hillside so the hole can drain. I've got a 1.5-inch deep channel underneath the first row of blocks that will lock in the walls when they're poured. Horizontal rebar in every row, locking into the vertical bars. I'll be using a surface bonding cement to hold all the block in place before pouring the cores--I'll put forms on the outside corners and tie some vertical rebar into those corners as well. Since I have access to the outside of the walls, I'm planning on wrapping in 9mm plastic just for adding water barrier from the outside. Will use a cementious waterproof layer inside.




So here's my big question at the moment. In addition to the cylinder portion of the pool, I have a stair access off the side of the cylinder that will start about halfway up, widening the pool to the side. In the diagram below, "Foundation 1" is already poured, and I'm building up the walls. When I get 4 rows of block completed, I'll need to pour "Foundation 2", which will be tied into the cylinder rebar and cores. Then I'll put in the remaining blocks and finish with a bond beam on the top.

The question is whether I can pour the bottom-half cores as one pour, then pour Foundation 2 as a separate pour, and finally pour the top half cores as a separate 3rd pour. This would make life quite a bit easier than trying to pour Foundation 2 with the bottom-half-cores empty, just so I can pour all the cores at once. If I can pour the bottom half independently, I would only pour up into the first few inches of the highest row, so that when I come back and pour the upper half, the concrete is mating up with the lower half deep inside the cinder blocks.

I can figure out how to do it as a single pour, but it will be harder to keep everything in place, and if it's not absolutely essential to the integrity of the concrete I'd prefer to keep it simple. I'm figuring the weight, freshness of the concrete, and the fact that I'll be using a bond coat on the interior surface will make this workable, but I'm a rookie and don't want to mess it up if it's essential to pour all cores at once.




My second question is about lighting and skimmer placement. This is a small pool (cylinder diameter of 5 feet), so I'm thinking 1 skimmer and 1, maybe 2 lights. Top view looks like this:


I'm thinking one light in the cylinder may be enough, but possibly a second light to better illuminate the stairs. Is that overkill for a small pool this size? I'm thinking 12v led.

For the skimmer, I'm just looking for the location to optimize collection. The space is pretty sheltered, with more swirling eddies than any consistent flow in any direction. I'm thinking of locating where the green block is shown below.




Some more pictures of the process to get here.

Thank you! I did go this route and did the first pour, layered the first rows of the foundation, and so far, it's worked out as expected. Will post more pictures soon.

Hello again. It's been another long hiatus on this project, due to weather. But I finally managed to pour the concrete on my cinder block plunge pool. I'm ready to surface the interior and have a couple of questions about layers.

My initial plan is to add a surface bonding concrete layer to finish the cinder block. Then I was planning to add a waterproofing layer. Now I'm considering a final aggregate stone finish. Is this doable? Can any of the layers be consolidated--e.g waterproofing and surface bonding cement? Or does this require 3 separate layers--and can they actually all be layered? Someone sent me a recommendation earlier for waterproof membrane... Do those work well with an aggregate finish over them?

The surface bonding cement recommends adding a Concrete Acrylic Fortifier to help with surface bonding. Would that conflict with adding something like MasterLife 300C crystalline waterproofing?

Thank you for any advice you can provide. I'll get better pictures after I finish removing the forms and clean it up a bit.

I have a quick question regarding the use of HydroBan and other Laticrete products for a small residential plunge pool (30 sq ft surface; 1000 gallons).

The concrete tank has been completed and has a rough surface ready for finishing. The final finish is intended to be a glass bead aggregate, with tile on the perimeter rim and floor only.

The plan so far is to apply HydroBan over the cement surface with the aggregate applied on top. However, reading the Laticrete literature, I'm getting spun up by all the different products--moisture shields, mortar beds covered by a second hydroban layer, etc. I'm assuming a lot of these products are for special and commercial applications, but I'm hoping for some clarity.

For a small residential plunge pool, is HydrobBan + Aggregate sufficient? Is a double coat of hydroban necessary for the top few inches of tile, under and over the mortar bed? Are vapor shields and other promoted layers necessary?

Thank you!

Thank you. I appreciate the feedback. That's a better explanation of Efflorescence than I've seen before--the Laticrete materials really don't give much context at all, just the product description and application.

Thank you!