Preparing and Shoring for a Subtropical Swimming Pool

Steps

1. 1

   Step 1: Video uploaded on 2023-09-06

   This video was uploaded on 2023-09-06.

2. 2

   Step 2: Planning the subtropical garden and pool

   Watch this part (0:00)

   We are clearing out the summer setup and excavating the entire garden to build a subtropical swimming paradise. In the corner, we will install a 3 by 3 meter in-ground pool alongside an extra veranda with a roof, and replace all current tiles with flagstones. A 3D animation outlines the general plan for the layout.

   Building an in-ground pool can be very pricey, so we are keeping costs down while ensuring the pool is fully insulated to swim year-round even in winter. Instead of building brick and concrete walls, we will use a Hydrium Ellerdely 300 above-ground pool which features an exterior steel wall suitable for inground placement. Around the outside under the pool rim, we will install 10 cm thick sandwich panels with a PUR filling to trap the heat.

   We will also reuse our previously built solar heaters and rocket stoves for the pool heating. Instead of regular concrete, we plan to use styrocrete, which is concrete mixed with styrofoam to increase volume and lower costs while adding insulation. Because styrocrete is weaker than regular concrete, we must add extra reinforcement to make it strong enough.

   What I'm going to use

   Item	Amount	Notes
   Hydrium Ellerdely 300	1	Above-ground pool with a steel wall used for inground installation
   Sandwich panel	unknown	10 cm thick with PUR filling for pool insulation
   Styrocrete	unknown	Concrete mixed with styrofoam for volume and insulation

3. 3

   Step 3: Planning the fence shoring and support poles

   Our biggest challenge is the fence because the pool will sit right in the corner, requiring us to dig directly against the fence line. To prevent the fence from sinking or sliding forward, we need a robust shoring plan before any excavation begins. We plan to drill three poles into the ground to a depth of 2 meters and mount 6 by 16 cm thick beams on top of them.

   We can add extra shoring to these beams and attach the entire fence to them to stop it from shifting. As we dig down during excavation, we can go 60 cm deep and immediately place concrete plywood plates against the earth, followed by another 60 cm and more plates with extra shoring to hold back the sand.

   We are putting 500 percent effort into protecting the fence to keep our neighbors happy. I chose these specific beams because we will need them for something else later in the project, saving us from buying new wood twice.

   What I'm going to use

   Item	Amount	Notes
   Beam	unknown	6 by 16 cm thick used for fence support
   Concrete plywood plate (betonplex plaat)	unknown	Used to hold back sand during excavation

4. 4

   Step 4: Drilling pole locations and building a water drill

   We mark the pole locations at measurements of 2.72 meters, 1.72 meters, and 2.72 meters. To drill the holes, I use a 60 mm PVC pipe with the back closed using a 3D print and a garden hose connector mounted on it. By pumping water down through the connection, the water flows around the nose and pushes all the loosened sand back up the sides.

   The pointed design helps navigate past stones, allowing me to twist and push the pipe through the ground until reaching a depth of 2 meters. Once the 2-meter deep hole is bored, I pull out the pipe, insert the pole, and immediately fill it back up with stabilized sand. I repeated this process until all six poles were drilled level with the ground and the surrounding sand was thoroughly tamped down for high stability.

   What I'm going to use

   Item	Amount	Notes
   PVC pipe	1	60 mm diameter, used as a water drill
   3D print	1	Used to close the back of the PVC drill pipe
   Garden hose connector	1	Mounted to the PVC pipe to pump water down
   Stabilized sand	unknown	Used to backfill around the installed poles
   Pole	6	Drilled to 2 meters deep

5. 5

   Step 5: Mounting and shoring the fence support beams

   I screwed the beams together and mounted them directly against the fence to shore it up securely. With the help of my assistants, I screwed the beams in place and added diagonal shoring to the corners. We also added front shoring into the ground to anchor it against the top tipping pressure, making the structure extremely solid so it cannot move anymore.

   What I'm going to use

   Item	Amount	Notes
   Beam	unknown	Screwed together and mounted against the fence

6. 6

   Step 6: Closing the first video and looking ahead

   That is everything for this first episode of the series. In the next episode, we will take out the paving and start digging so the project can really start taking shape. Do not forget to subscribe or click the bell icon so you get a reminder when the next video goes online.

   • Removing the paving

   • Starting to dig

   • Future special surprise and live streaming

7. 7

   Step 7: Takeaways

   • Use an above-ground steel-walled pool and sandwich panels to keep inground pool costs low.

   • Mix styrofoam into concrete to create insulating styrocrete while saving on volume costs.

   • Drill deep support poles using a custom water drill made from PVC pipe to stabilize the ground.

   • Shore up adjacent fences carefully with beams and plywood plates before digging deep trenches.