Excav cinder blk foundation-waterproof & new backfill

[mthibo]

I have a small ranch home approx 40 years old on cinder block foundation and was getting some water in the unfinished basement when it rained. After research and getting estimates from professionals. I resolved the problem by installing a surface drain connected to approximately 25 feet of subsurface drainage pipe to reroute the runoff. Heavy rains the last several days and no water in the basement. Hooray!

In conjunction with the drainage approach, I excavated the foundation where the water was coming in (approximately 15 feet across, 7.5 feet deep). I planned to waterproof the exterior and install a drain at the bottom of the foundation. During a rainstorm after the excavation was completed but before the surface drain and pipe was installed, I observed water coming from inside the cinder block out into the trench where I excavated. The leaks were 2 strong streams - the bigger one was nearly the size of a garden hose. The drainage solution also solved this problem.

3 Questions:

1. Is it wise to proceed with the exterior waterproofing in this situation (water flowing from the foundation out)?

2. If waterproofing makes sense, what products should I use? What have others had success with? What characteristics should I look for in products?

3. New backfill - what is the appropriate backfill material(s)? The excavated material is heavy red clay (I'm in Georgia) - I don't think that is the appropriate material.

[Rich]

Interesting situation with water flowing from inside out.. is there a broken pipe or did it eventually stop flowing?
I would use a spray applied waterproofing material like ProCor or similar.
I would also suggest an acceptable backfill material. Clay soils will expand and contract as it saturates and desaturates. Eventually it will crack your foundation.

[mthibo]

Thanks Rich for reply

The water stopped flowing after the rain ended. Then once I put the drain and drain pipe in - it has not returned at all and we have had some subtantial downpours since then.

On the fill issue - I found that I should use gravel then a perforated drain tile/pipe, then more gravel on top of that. At what point (I have approx 90 inches to fill) should I stop with gravel and switch to something else? What other material - just fill dirt?

[Rich]

gravel around the drain tile only needs to be a max of 1' around the drain pipe/tile. Then you can start your fill from there. And yes fill dirt is ok.

[mthibo]

Thanks again for reply Rich.

I ended up using a lot more gravel. Everything has turned out well. No more seepage in the basement after the surface drain was installed.

Now to clean up the cinder blocks on the inside!!

[Rich]

Whatever works :) .. glad to hear everything worked out.