Type of basement construction / drainage?

shaun_m · 01-11-2011, 06:37 PM

I'm trying to identify the construction and drainage methods used in my basement and I'm wondering if any of contractors or building experts on the forum can correctly identify it?

I live in NJ (north near NY border) and i'm told this kind of slab is common - but is it a floating slab to allow for movement? maybe it's a french drain? trench drain? Can I tell what type of block I have? and if it's hollow and draining to this trench? and the million dollar question - Can I seal it from inside the basement in order to finish my basement?

jomama45 · 01-11-2011, 10:04 PM

Quote:

Originally Posted by shaun_m

I'm trying to identify the construction and drainage methods used in my basement and I'm wondering if any of contractors or building experts on the forum can correctly identify it?

I live in NJ (north near NY border) and i'm told this kind of slab is common - but is it a floating slab to allow for movement?
Floating slab yes, but the trench is more than likely a "homeade" toe drain.

maybe it's a french drain? trench drain?

I'd consider it a "retro-fit french drain" myself. The reason these were typically installed was to collect water that leaked thru the wall above the floor.

Can I tell what type of block I have?

They certainly appear to be typical hollow core block, more than likely heavy-weights. They also appear to be 8" wide.

and if it's hollow and draining to this trench?

You'll need to dig out some of the stone/gravel/debris in the trench. If it's a retro-fit job that was installed for wall leakage, they very well could be either 2 or 3 holes in each block (below floor level) for interior cavity drainage.

and the million dollar question - Can I seal it from inside the basement in order to finish my basement?

That's the loaded question..........

Have you witnessed any leakage before? How long have you lived in the residence?

gregzoll · 01-11-2011, 10:15 PM

My slab is a floating slab, and some time when the previous home owner/owned since built over 70 years ago, had the gap filled with concrete between the slab & block foundation. The only water leakage that we have had with our house, was due to a clogged gutter when the hurricane came through back in 2008. After the gutter was cleaned out, and downspouts extended a little further, we have no water leakage in our basement.

shaun_m · 01-12-2011, 09:53 AM

thanks for the info and insight jomama and gregzool

Jomama - I've lived here a little over a year, basement was dry at inspection time, no sign of any new leakage, dampness or musty smells. There was a faint and old water line 4 inches up where it looked like many years ago the basement had flooded - maybe that's why the trench was put in?

Since I've lived in the house I have not seen any water on the walls but during the summer after a heavy spring last year it smelt faintly musty. During spring we had heavy rain falls and the ground was saturated. The sump pump was working a lot, the gravel at times looked wet. Our neighbors on both sides flooded a few inches but we stayed dry. I had graded the soil around the house and all of my gutters have guards one, downspouts are about 1foot+ away from the house.

I made the assumption that the drain and sump pump were taking away the outside water that was coming into from foundations and possible walls down to trench and that therefore i could close the inside. Or at least that's what I'm hoping to find out

I'm going to dig out the gravel and take a look
Shaun

shaun_m · 01-12-2011, 04:38 PM

I dug the trench out. It was only 3 inches deep, gravel on top of dirt. I can feel the gravel going under the slab.

It seems like I could fill this in?

jomama45 · 01-12-2011, 06:57 PM

I take it that you're hitting the concrete footing there? Looks typical to me, and it doesn't appear that there are any weeps in the bottom course of block.

I certainly can't guarantee over the internet that the wall isn't going to leak, because odds are it will someday, just like the majority of basements. How long from now is the only question. I do think you'd be fine to fill the gap in with std. Quickrete, as long as there is absolutely no evidence of water seepage.

shaun_m · 01-13-2011, 11:32 AM

After the 3 inches of gravel was just dirt so I'm not sure if it was the footing. You may of gathered that I'm trying to figure out what to do with this trench before I finish my basement.

Are you familair with Platon interior wall moisture control or similar products? It a dimpled wall covering that allows water that penetrates the wall to be directed - I'm guess into the trench.

http://www.systemplaton.com/PDFs/Int...er_Control.pdf

Maybe I should put that under my insulation?

Shaun