In our desire to be as independent as possible, we wanted to install a tank for recovering rainwater.
At the outset, we hesitated to buy a prefabricated tank, but given the cost, we quickly geared towards a self-built tank.
We took the shovel that dug the foundations for making a "hole" of 4 by 4 meters wide and a depth of about 2 meters with the natural terrain.
The aim of departure was to mount a tank of 27 m3 (ie 3mx3mx3m)!
Once the house is located and the final heights are known, we have decided to make a tank 3mx3, 5m ground to a height of 2 m (only) !
For information, precast concrete tank 10 000 l costs about € 1,500 (not included). Although we have not yet finished, ours should we revert to an amount substantially equal to 21,000 liters.
And how they made a tank réupération??
On paper it's pretty simple (really!). First, we must make a concrete slab on the ground. For reinforcing concrete, he must make a wire mesh that is cast in cement. Do not forget (like we did) out of rebars of 10 mm in diameter by 2 spaced ten CM every 20 cm. These irons come out in blocks to be cast in formwork and concrete.
As the slab was poured without rebar, it was necessary to pierce the slab chipper, put the irons and seal the slab ... or how to make simple when you can make it complicated!
Now then, when you have your army with your slab rebar coming out, you can start the pot itself. For insiders, it's the same principle as a pool. For others you need to make formwork blocks (or Stepoc).
These are Block (Arghhhh) hollow. You put the top on your slab tucking the rebars in the holes. There should be 2 holes in irons. The blocks fit together to hook it into each other by small ergos. It's pretty simple? yes, but it must be Maousse strong! We must be careful to seal the top level if the result will be quite galley.
Once sealed blocks must be put rebars of 8 mm in diameter horizontally by tying them to the vertical rebars (those 10mm). It's pretty tedious, but essential to the homogeneity of the structure.
Once the first row asked, you place the second set without mortar. When you've gone around (it takes longer to do than write), you prepare the cement loaded with 300 or 350 kg (follow the directions of the bag). You can then put another layer of rebar from 8 mm to the horizontal ...
You repeat this procedure until the final height. You will find tips to slide blocks along the rebar. If you have more than 2 meters, I suggest you put smaller chains and bring back then.
I summarizes. For a 21 m3 tank, you will need: -1
concrete slab Armed 4mx3, 5m wide
- rebars of 10 mm in diameter around the edges of the slab. These bits are arranged 2 by 2 cm every 20
- blocks of 50x25x20cm in bancher
-120 meters of 8mm rebar diameter
- cement, sand and gravel to fill the formwork blocks (count fifteen bags for all)
Tips osteo requisitioned after the damage: pay attention to your joints! (I left my back) ... and rebar that exceed it's pretty dangerous!
Once the tank made, you will need to coat it inside to seal it and put a "hat". This will be the subject of another article ...
For new readers of this blog, I invite you to reread the archives for the history of the house.
For those who want professional advice more specific (CGR auditors for example), you can contact me at
alpha-bat@laposte.net
