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Hi,

I need some advice on the RCC sump. I got an RCC sump constructed 10 days back but I am noticing that the water level reduces about 1 inch every day. I understand that some water might get absorbed initially by the concrete but it does not seem to stop.
The contractor had added Dr Fixit while doing the plastering.

How long should I wait?( for the water absorption to stop)
Does this typically happen in all the RCC sumps?
Is this a problem?
Do I need to do anything else?


regards,
Manish

Manish,
i am sure there will be a leak in the sump.
i don't know how big your sump is but an inch a day is bit too much.

these are the steps to check the sump construction.
1. after construction of sump don't fill the side of the sump. (most of the masons confidently say that after plastering sump will not leak but they are wrong)
2. let the sump be cured for 4 to 5 days ( no hurry)
3. and then fill the sump till it's neck and wait for an hour to 24 hours, you will notice all the leaks!
4. remove the water.
5. where ever the leak is there remove a layer of concrete may be a around 10 mm think and then apply dr fixit leak proof couple of quote with a gap of 5 hours.
6. if you sea bigger leak remove concrete around 1 or 1nd half inches and then do the same thing in step 4 and then do plastering again.
7. after a day fill the water again and check for the leaks, when everything is clean then go ahead filling around the sump.
this process will take 10 to 15 days. i have done it many times and this small struggle will definitely give lot of confidence buildings base.

for your particular case once u remove all the water in the sump and carefully check for the places where you have more wetness on the sump wall (sometimes there will be spots when whole sump will be dry but these spots are little wet)
That means there is a possible leak (not 100% sure).
but for you if the water level is reducing after 4 or 5 days then you should suspect it as a leak.
note people may say that water is evaporating from the sump, yes it will but not one inch for a day, i am sure, i have done the testing. max evaporation per day i have notice is around 2 or 3 mm that all, especially in this weather.

let me know if still need more information.

ragalax wrote:Manish,
i am sure there will be a leak in the sump.
i don't know how big your sump is but an inch a day is bit too much.

these are the steps to check the sump construction.
1. after construction of sump don't fill the side of the sump. (most of the masons confidently say that after plastering sump will not leak but they are wrong)
2. let the sump be cured for 4 to 5 days ( no hurry)
3. and then fill the sump till it's neck and wait for an hour to 24 hours, you will notice all the leaks!
4. remove the water.
5. where ever the leak is there remove a layer of concrete may be a around 10 mm think and then apply dr fixit leak proof couple of quote with a gap of 5 hours.
6. if you sea bigger leak remove concrete around 1 or 1nd half inches and then do the same thing in step 4 and then do plastering again.
7. after a day fill the water again and check for the leaks, when everything is clean then go ahead filling around the sump.
this process will take 10 to 15 days. i have done it many times and this small struggle will definitely give lot of confidence buildings base.

for your particular case once u remove all the water in the sump and carefully check for the places where you have more wetness on the sump wall (sometimes there will be spots when whole sump will be dry but these spots are little wet)
That means there is a possible leak (not 100% sure).
but for you if the water level is reducing after 4 or 5 days then you should suspect it as a leak.
note people may say that water is evaporating from the sump, yes it will but not one inch for a day, i am sure, i have done the testing. max evaporation per day i have notice is around 2 or 3 mm that all, especially in this weather.

let me know if still need more information.

Thanks ragalax. The capacity is around 6.5K litres. I did curing for 6 days. The level decrease seems to be reducing littlebit. I will watch for another 2-3 days and if it does not reduce further then will do what you have suggested. The mason is confident it is not a leak but they will say this to avoid ownership.

Hi,
As per my experience, most of the leakages are from the sump Steps they place in wall. The masons and helpers, after plastering, should not touch the step but illogically climb using that, making a gap for water to seep.
My suggestion is to empty water until the steps, apply Mseal to place where step is fixed to wall, after the mseal cures completely, refill water.
Im sure there will not be any leakage after that. (maximum probability)
Thanks,
Bharath