akinloluwao:
Its very simple. They will sink it by digging the sand around it. Just watch them when they are at it..lol

nnemak:
Today, they pumped water out of it and I noticed serious digging inside.

mufutau55:


Good. We are all learning sir.

Hajji M.

nnemak:

Dear Experienced builders,

Until recently i assumed these structures were put in place to temporarily collect water to aid building as i notice they disappear after the building was completed.

I even had an argument with my spouse that it was not really possible for it to be submerged later until i noticed one out of the two that's been constructed adjacent my residence had submerged and was severing as septic tank!

Please can someone educate me on this?

Am following the one that is still on the surface as i want to see when it would "disappear" submerge

opalu:
Also don't let the pipes to run into the septic tank at middle point. Because most Nairalanders whose site I went to correct, the sewerage pipes enter the tanks at middle so it get full easily. They got the slope wrong from the manholes and Inspection chambers.

Almaiga:
What's the difference between a Septic tank and a Soak-away.

Konnektions146:

I have not had anything to do with you but i so much ADMIRE you Sir.
a typical of a role model
not some Adults that insult and rain abuses like kids.
Papa Hajji M.,
You inspire a lot of people here . Thank you

Almaiga:
What's the difference between a Septic tank and a Soak-away.

suco01:
wilt all the xplanation opalu, d part I no get is hw u'll dig till dat tank enta d hole fully b4 pipping and covering. me neva understand am cos am used to d normal one where u dig, build, use pillat @ edges .

mufutau55:

Piping can go on top edge when they are doing the decking for it, they still have to deck the top.

Hajji M.

Bro hw wil d building on surface go down without it tearing apart.?.

notindome:


The sewage pipe entering into the septic tank from the IC/MH, Was there a kind of sleeve used to make its entry point on the wall of the tank when casting? or it will be chiselled out?

opalu:


Chiselling or sleeves can work. But most times the former is practically feasible except you can predetermine the exact spot it will go in at casting stage.

opalu:
[b]Luckily I have cast and buried very many of such tanks. And I want to explain it in very plain manner.

Remember that in the villages and in many towns, to do your soakaway, you just dig the ground and use blocks to build the walls of the soakaway inside the dug pit. Then you turn some blocks so that the waste liquids can flow through the holes of the block into the soil. Then the solid waste is left inside the soakaway.

But in towns and cities where the water is very near like in lekki and VI, if you do that normal soakaway, the water from the ground will turn it into a swimming pool in just 1 day or 2! You cannot use blocks to do the walls because the water pressure plus earth pressure will collapse it inside the ground. And even before then, water would pass through any holes allowed into it.

But people in the house must poopoo. So the best solution builders adopt is to cast the whole thing on the ground after reinforcement and carpentry works. We use waterproof admixture to improve the water resistance of the structure. We also plaster it and apply felting to it (if the client doesn't over negotiate).
Thereafter, some guys your are expert in SINKING septic tanks enter inside and continually dig and dig until the entire structure reaches the required level. If you don't engage a good plumber and a land surveyor, they may sink the tank below the required level therefore making it not work properly. Or they make it to be too high that it would not flow with the compound level.
So after sinking it, you will start seeing water inside like swimming pool except you did it in very dry season. You use 2 or 1 pumping machine to bail out the water to the point that it becomes very dry. Then suddenly you seal the bottom using DPM, chemicals and cement mortar. That sealing stops the water completely. They way you seal is systematically. You seal one side and allow space for water to pass through another place until the sealing dries. Then block that hole and run your rebars and cast fast fast fast.
Please don't try this at home. Because many who we explain like this to jump to "Do It Yourself " and they mess up the whole septic tank.

Any septic tank done wrongly will get full easily and they will have to pump the sewage out every 6 months or 9 months or even 3 months. A good one will last very long before needing a pump. The waste water can have its own compartment or just to flow into the public drain. I mean water from kitchen and bath etc.

After the bottom, the top slab is cast using formwork and rebars also. There must be openings with precast concrete cover. Your interlocking should pass over the tank if you got the level perfectly. Also don't let the pipes to run into the septic tank at middle point. Because most Nairalanders whose site I went to correct, the sewerage pipes enter the tanks at middle so it get full easily. They got the slope wrong from the manholes and Inspection chambers. [/b]

opalu:
[b]Luckily I have cast and buried very many of such tanks. And I want to explain it in very plain manner.

Remember that in the villages and in many towns, to do your soakaway, you just dig the ground and use blocks to build the walls of the soakaway inside the dug pit. Then you turn some blocks so that the waste liquids can flow through the holes of the block into the soil. Then the solid waste is left inside the soakaway.

But in towns and cities where the water is very near like in lekki and VI, if you do that normal soakaway, the water from the ground will turn it into a swimming pool in just 1 day or 2! You cannot use blocks to do the walls because the water pressure plus earth pressure will collapse it inside the ground. And even before then, water would pass through any holes allowed into it.

But people in the house must poopoo. So the best solution builders adopt is to cast the whole thing on the ground after reinforcement and carpentry works. We use waterproof admixture to improve the water resistance of the structure. We also plaster it and apply felting to it (if the client doesn't over negotiate).
Thereafter, some guys your are expert in SINKING septic tanks enter inside and continually dig and dig until the entire structure reaches the required level. If you don't engage a good plumber and a land surveyor, they may sink the tank below the required level therefore making it not work properly. Or they make it to be too high that it would not flow with the compound level.
So after sinking it, you will start seeing water inside like swimming pool except you did it in very dry season. You use 2 or 1 pumping machine to bail out the water to the point that it becomes very dry. Then suddenly you seal the bottom using DPM, chemicals and cement mortar. That sealing stops the water completely. They way you seal is systematically. You seal one side and allow space for water to pass through another place until the sealing dries. Then block that hole and run your rebars and cast fast fast fast.
Please don't try this at home. Because many who we explain like this to jump to "Do It Yourself " and they mess up the whole septic tank.

Any septic tank done wrongly will get full easily and they will have to pump the sewage out every 6 months or 9 months or even 3 months. A good one will last very long before needing a pump. The waste water can have its own compartment or just to flow into the public drain. I mean water from kitchen and bath etc.

After the bottom, the top slab is cast using formwork and rebars also. There must be openings with precast concrete cover. Your interlocking should pass over the tank if you got the level perfectly. Also don't let the pipes to run into the septic tank at middle point. Because most Nairalanders whose site I went to correct, the sewerage pipes enter the tanks at middle so it get full easily. They got the slope wrong from the manholes and Inspection chambers. [/b]