Installing a Sump pit without a french drain?

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steppinthrax

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I reside on the eastern coastline in a two-story brick house with a basement that was constructed in 1986. The soil composition in this area is predominantly silt clay. Although my home lacks a sump pump, there are occasional humidity issues during the summer months, necessitating the continuous operation of a dehumidifier to prevent musty indoor air. Remarkably, heavy rainstorms do not result in any visible water seepage. Nevertheless, there is one specific corner in the basement that tends to get damp during rainstorms. This particular corner coincides with the starting point of the attached side garage, creating an "in-corner" from the exterior perspective. We've made improvements to our gutter system, and there are no issues with standing water. It's somewhat perplexing to me why this area gets wetter than others, but it may be due to its positioning as an "in-corner," which can accumulate water.

Considering this, I've been contemplating the installation of a sump pump in that corner, not only to address the localized dampness but also to generally lower the water table after rainfall. I've also come across information suggesting that many basement waterproofing professionals typically employ an interior French drain system, routing it to the sump basin. My question pertains to the necessity of implementing such an interior French drain. Additionally, I'm curious if there's a drain tile system that I could connect to after creating an opening in the concrete floor. I've observed several instances on YouTube where installers simply punch a hole in the floor and drill multiple 3/8" holes around the sump basin.
 

Reach4

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I have put in a sump into a basement without connecting to a parameter drain. If you think there was a perimeter drain, and you got your tile sewer line replaced with plastic, they might have disconnected the perimeter drain during installation of the plastic. If you do want to connect to the perimeter drain, I would think that sump should be outside of the foundation.

If you will not connect to the perimeter drain, and want your sump in the basement, what I would consider is getting a sump liner. Maybe even upgrade to a sealed sump, which is stronger. You will not maintain a seal. Deeper is better.

Digging during the dry season will be better, so you don't deal with ground water rising. I found a stand-up bulb planter to be a good tool for removing some slugs of clay.

In my case, there was reinforcing wire in my concrete, and I used the wire to help hold the sump down until the concrete around the rim hardened. I used a bolt cutter to clip that strong wire mesh.

Under my concrete was a plastic sheet, and then smooth small river gravel which I called pea gravel. I saved that for reuse. With the sump liner in place, fit pea gravel down the sides filling the hole space around the sump liner.

I felt that the pea gravel layer is what would conduct the water to the sump. So I drilled holes in the liner at about that level, about 3/16 to 1/4 inch, to hold back the gravel but permit water flow. Today I would not put in low holes.

This should be able to get you started thinking.

Regarding your inside-corner, consider where your gutters deposit that rain water.
 

steppinthrax

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I have put in a sump into a basement without connecting to a parameter drain. If you think there was a perimeter drain, and you got your tile sewer line replaced with plastic, they might have disconnected the perimeter drain during installation of the plastic. If you do want to connect to the perimeter drain, I would think that sump should be outside of the foundation.

If you will not connect to the perimeter drain, and want your sump in the basement, what I would consider is getting a sump liner. Maybe even upgrade to a sealed sump, which is stronger. You will not maintain a seal. Deeper is better.

Digging during the dry season will be better, so you don't deal with ground water rising. I found a stand-up bulb planter to be a good tool for removing some slugs of clay.

In my case, there was reinforcing wire in my concrete, and I used the wire to help hold the sump down until the concrete around the rim hardened. I used a bolt cutter to clip that strong wire mesh.

Under my concrete was a plastic sheet, and then smooth small river gravel which I called pea gravel. I saved that for reuse. With the sump liner in place, fit pea gravel down the sides filling the hole space around the sump liner.

I felt that the pea gravel layer is what would conduct the water to the sump. So I drilled holes in the liner at about that level, about 3/16 to 1/4 inch, to hold back the gravel but permit water flow. Today I would not put in low holes.

This should be able to get you started thinking.

Regarding your inside-corner, consider where your gutters deposit that rain water.
Someone told me a while back (10 years or so) that installing a sump pit without direct drainage system to it will only remove water maybe 3' around the basin.
 

Reach4

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I expect the cone of depression and flow distance can vary according to what kind of gravel is under the concrete.

Thinking of the term, cone of depression, would tend to support drilled holes farther down.

Now would a big long French drain, or two, feeding the pit be better? Sure. Sounds a lot harder.
 
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