Stopping Leak in Concrete Water Reservoir ??

[James]

I get water from a spring, and have water storage in a concrete tile, 30 inches wide and about 5 feet tall. I have used this for many years.

The concrete tile (similar to a culvert, but shorter) has developed a crack down the side, and water is dribbling out. Luckily, my spring water flow this time of the year is so good that I still have enough storage. But, during the fall when the water flow is very low, this leak will make me lose as much water as I get from the spring.

I would like to know if there is a way that I can repair this crack. I have used Water Plug before, but I have used it in places where I needed to fill an obvious hole or void. I don't know if I can get it to "stick" to a crack, and I don't think the crack is wide enough for the Water Plug to actually get into the crack itself.

Any ideas on this, on the best way to seal the crack ?? Should I be trying to seal it from the inside, or the outside, or both ?? Is there a better product for this application , other than Water Plug ??

Thanks for any tips !!

--James--

[Edwin Pawlowski]

Inside is always best. What caused the crack? Will it get worse or have a catastrophic failure? Most sealers last for a time but eventually let go again. Consider some sort of lining, maybe a fiberglass lay-up with polyester resin or epoxy.

[Srgnt Billko]

Might try gouging the crack out to give the stuff more surface to stick to. I use marine 3M 5020 but I don't know if it is safe for drinking water.

[BobK207]

Take a look at this stuff

[JerryD(upstateNY)]

If you can put a pump in the tile to keep the water below the crack for a while, you could then grind/chip out the crack so you get more surface area for the sealer to adhere to.

[Daniel]

Much easier to seal it from inside. Outside sealing would required injections and that's not a DIY job.

But you first have to dry up the area to repair. If it is at the bottom of your tank, trouble for you as it will take few dry days to get the crack in workable conditions plus one or 2 days for curing of the sealer before refilling the tank..

Then, you will have to open that crack to provide room for the sealer. And to evaluate if it is a structural crack or a simple shrinkage crack.

If it is structural, i.e. putting the whole stuff at risk of collapse, use epoxy BUT make sure that this epoxy is compatible with drinking water (Usually NSF 61 is the reference for that). If it is a simple shrinkage crack, any sealant compatible with drinking water will do the job but beware that they don't last long, 2 to 3 years maximum.

If it is really a mess to get that crack area to dry up, you may try to locate materials that can be applied underwater. The epoxy material as mentioned in another post seems not to be compatible with drinking water and I am afraid it will be difficult to locate one. Be demanding on that certification, it is serious.

If you cannot find, then you are left with no choice but to call a contractor qualified and equipped for injections. Make sure his injection resin (Epoxy or, more probably, polyurethane) is certified re. drinking water.

If you tell us in which State you live, I may be able to locate one or 2 for you. Cheers Daniel

[BP]

Cracks need to be enlarged before applying hydraulic cement (Water Plug or others). I use a cold chisel and just follow the crack, one blade width at a time, making a 1/4" v-shaped gouge in the wall. Once the entire crack is chiseled out I clean it with compressed air to get the dust out, then wet it, then apply hydraulic cement, pressing firmly into the crack with a small amount that is slightly too wet. Then once again with material that is the right consistency. Do both sides of the wall.

[James]

Thanks to all of you for these good comments !!

--James--

[SJF]

Another thought --

I seems your tank was probably made from a 5-foot section of 30-inch concrete culvert pipe. It may be as easy to replace the pipe as to repair it. Call your local road maintenance office (state, county, city) for information on possible suppliers.

--- SJF