Pour the ground slab in sections?

Hello everyone,

we are currently planning our outdoor area and want to build a pool ourselves. The pool will be built from 17.5 cm concrete shuttering blocks and will be completely underground on two sides and about 2/3 above ground on the other two sides. We have put the cost calculation on paper so far and now it’s time to cut costs and see where we can save money. This includes the base slab. Originally, a concrete truck with a pump was calculated, but this is one of the largest financial items in the plan, so we would like to create the base slab ourselves. There is definitely craftsmanship skill and the appropriate male power available.

The pool will be 7x4 meters and with a 20 cm base slab that would be about 5.6 m³ of concrete that needs to be processed. A lot of concrete if you want to mix and process it by hand with the mixer.

Therefore the question is whether the base slab can also be made in partial sections.

The structure would be 20 mm gravel, then a mesh of 2-layer steel mats. The pool will have two levels connected by a slope. Can the base slab be divided into these 3 sections, as shown in the sketch, and created separately or will this not lead to a result that holds in the long run? The connection reinforcement would be present for the individual areas.

I am looking forward to your knowledge and feedback. Thank you very much.

Foundations can also be built in sections if done correctly. But honestly: if your budget is so tight that you are cutting costs on the concrete mixer and pump, you shouldn't be thinking about a pool and its operation. Should it be a liner pool? Counter-current system? What kind of pumps and filtration + dosing, cover, heating...? Even if you have the manpower and skill, sometimes it still makes sense to do it properly. You also need to have the raw materials delivered. If you get them yourself, you will probably have to make more trips and also factor in vehicle wear and tear, etc. You also have to feed the crew. Currently only one additional person not living in the household.... With a car and pump, the thing is done in max. an hour.

Thank you for the hints. Everything is fully planned and budgeted with 15,000 euros. Whether [Folienpool] or [Fließen] is still unclear at the moment, but we already have quotes for laying the foil from a professional. A counter-current system is nonsense... it is only meant for cooling. Technology etc. has already been fully planned. Material will of course be delivered by the building materials supplier, and the excavator is ready to dig the hole. For me, it is now really only a question regarding the base slab. When you write that it can be done in sections if done properly, the question now arises how done properly looks. Can you write something about this or are there sites where you can see something like that? Unfortunately, I haven’t found anything. And if I do it myself and can save a four-figure amount, then the catering for the crew is also included in that. Then there is a bit more buffer again to plan the rest of the green area.

At 7 meters, a counter-current system makes sense. Of course, not if it's just for splashing around. Better use foil. In our latitudes, tiles outdoors are not optimal. How high are the opportunity costs if you do it yourself? +Helper? But we don’t want to be petty. You should be able to manage 5.6m3 in one day with help by hand. Simply strip the formwork and do the connection reinforcement. You didn’t address many details of the pool. Too bad. There are also forums that deal exclusively with pools and their construction. Please plan well. 15k is not very much for a pool of this size. Please continue to report on the project.

But honestly: if money is so tight that you save on the concrete mixer and pump, you shouldn't be thinking about a pool and its operation.

I agree. Seven meters short without countercurrent but two depths (swimmer / non-swimmer ?) with a slanted stepped transition, sounds to me on the whole like "I don't believe that, Tim"

Since this is a thread about the topic of the base slab, I did not assume that you were interested in the story surrounding it, so I did not go into detail. I also did not place it in the garden section since it primarily concerns the topic of the base slab. However, an admin is welcome to move the topic if it fits better elsewhere.

But gladly more details. It will not be a chemical pool but a natural pool. Divided into use area/swimming zone and regeneration zone. The technology will be installed by Glenk Teichbau, i.e., deep suction, skimmer, elbow filter sieve, and pump to the regeneration zone, where the water is finally cleaned by the plants. That part is already fully planned.

The 2 steps of the pool are due to the built-in stairs leading inside. The "shallow area" will be 1.5 meters deep and then slope down to 2.0 meters. This has nothing to do with swimmer or non-swimmer areas. Since, as mentioned, it will be used more for cooling down, a counter-current system is not an option. The pool will not be heated directly. In spring and autumn, additional heating will be provided in the form of a self-built system made of PE pipe, temperature controller, and pump. The PE pipe will be laid out in a serpentine pattern on a fully south-facing 25sqm garage roof.

However, I have to revise my calculation again... I just looked at my "old" calculation. With the addition of stone thickness and an additional 5 cm edging all around plus the technology shaft, we would be looking at 7.4 cubic meters of concrete to be processed.