Adding interior drain tile to a basement
 

So, while I was chipping up a platform for my solar hot water tank, I found that there was no poured floor under it. Ever since purchasing the home I've had water issues in the basement. Its not horrible, but every spring and if we get a good few day downpour I get a little water down there. On top of that, I need a dehumidifier in the basement in the summer to keep the moisture in check, and that thing uses a fair amount of juice. So, obviously I'd love to fix it.

As the basement is now I do have a sump croc. It does fill and pump water out of the basement. But, there is no drain tile going to it, so whatever water gets there is just what seeps through the ground.

As I see it I have two options:

1) Remove the entire floor, lay down rock for good drainage, at this point I could add insulation even, and repour the floor. This is a ton of work, but is probably the best way to fix the problem. On top of it I'd like to put some dry lock on the walls as Ryland has suggested and at that point I think I'd be pretty well off.

2) This option is a lot less work, but I'm not sure if it will do everything I'd like it to. I would chip a trough around the outside wall of the basement. I'd lay rock down in the trough and put down drain tile. Then, I would simply repour on top of the trough area. I'd also dry lock the walls and see how that would do.

My question to you guys is basically do you think options #2 is going to get rid of enough water, or should I just go all out? Is there another option I'm not considering? I can tell you from the tiny bit of smashing the concrete platform I've done so far, it is gonna be a huge pain taking out the entire floor. So, I'd like to avoid it if possible.

I am kind of coming into this discussion mid-stream, but, are there any grade issues around the house? If the problems increase when there are downpours, or spring thaws, then maybe there some relatively easy fixes outside.

Most things are obvious; grades should slope away from the foundation, eavestroughs should have lateral extensions to pipe water away, that kind of thing. But there are some less obvious thins to look for.

-Vegetation around the foundation. Some plants, shrubs and trees have aggressive root systems that head straight for your outside footing drains, if your house is new enough to have them. You may have to remove the plant, and dig down to the drain to clean it out. If you have to do this, it may be a good time to make changes to your moisture barrier on your wall.

-Window wells, if you have them. They can gather a lot of water and let it seep down and in. This is kind of a pet peeve of mine, but you will often see "experts" on DIY television shows install a drain in a window well, and dig straight down and connect it to the existing footing drain. Why on earth would you want to pipe more water to such an important drain?

-Soil type. I have seen situations where the indiginous soil is very tight and clayish, and the builder backfills around the house with a looser, more porous soil that lets water travel straight down and accumulate at the foundation wall. This can be a tougher one to fix, but surface grading can really help.

-Critters; mice, moles, chipmunks and ants can all tunnel around your foundation, making a network of passages for rainwater.

One solution, at least a partial solution, is to install a perimeter drain around the outside of the foundation; at a depth of about 24 inches install a bed of clear stone with perforated drainage pipe, and more stone on top, with a protective layer of filter fabric to keep the soil from plugging the stone and the pipe. Run the outflow to a low corner of your property if you can, or to a sump basin and pump it out.


Back to the inside, if it were my basement I'd go with the perimeter approach first. If you should find you still have water issues in the middle of the floor you can always work your way inward and connect to your perimeter pipes.

Hope your arm feels better soon!

The house has an old fieldstone basement. It has no drain tile inside or out. The grade away from the house is quite adequate after talking with a few people.

I kinda like the shallow exterior drain tile approach. Perhaps I could add that if one of the interior ones doesn't work out.

I have done that successfully for customers before, especially if the problem co-incides with precipitation. In the winter time the ground adjacent to the foundation seldom freezes as tight as it does further away, and sudden rain and melt off soak in quickly here, and cause problems.

I basically did your option 2, before I even heard of underfloor insulation. Overall it has worked pretty well. Before the drain-tile install I would get water leaking with every rain. After rain has not been a problem. That said I have also noticed some shifting of the remaining slab in the middle of the room. My guess is from unevenly draining from the soil that has been wet since the house was built. I figure at sometime later I will have to rip out the whole floor and make it level, reinforced, and insulated-like your option 1.

Well obviously #1 is the way to go but it'll be a ton of work. If you do that one thing you'll have to keep in mind is that many field stone foundations don't have a footing at all and the walls aren't really all that strong. So putting a perimeter drain on the outside is out of the question because when you excavate the entire wall could collapse. You'd actually probably have a difficult time finding an contractor who would agree to do it. I haven't been able to fine one that will. If you go with #1 you also need to think about where you'd put the old slab chunks and soil you remove. Then after you lay down the XPS and drain tile you need to screed a new slab, which isn't something I personally feel capable of doing well. So you might need to hire that one out. Last winter I got a bunch of quotes from people about doing this and it was a couple G's just to pour, screed and float the slab including the cost of concrete and delivery. But my personal opinion is if you're going to do it, do it right the first time and don't have any regrets later on. A nice new slab with no moisture damage, good drainage, R10 and a radon stack is the balls.

Wish I were closer as I'd come out to lend a hand in the demo and excavation.

Edit:

I was just checking out you therad about removing that pad and I saw some columns. They look like the kind that have an acme screw on them to jack up a sagging floor. Correct? If that's the case you could pour proper footings for them when you put in a new slab and use proper lally columns.

Hauling lots of rock into a basement isn't much fun. You probably do not need to remove the whole floor. I would recommend narrow tile trenches connected to your sump under the floor near any wet walls (i.e. if the basement stays dry along one wall you don't need to trench near it.) If you can identify the direction of groundwater flow you may only need to install a tile trench along the up-gradient wall. Judging natural gw flow may be hard though since your current sump will influence any observations.

How big is your basement? the proper way of course is a whole new floor with vapor barrier and foam as water will not come up thru 6 mil plastic an 2" of foam, but if you have a large basement and your stairway is in to the center of your house like a lot of basements are then hauling out wheel barrow after wheel barrow of cement and dirt is going to take a while even if you bribe your friends with food and beer! and I bet your basement ceilings are not tall enough to lay a 2nd slab over top of the one you already have.
With your sump pump pit, have you tried digging it deeper and installing crushed rock in the bottom? that is more or less how mine is and it drains without a pump, working more or less as a large floor drain, that might also just work with my soil type.

Have you dug up around the outside of your house to seal the foundation from water from the outside? sure the soil has good slope, but 6mil plastic and 2" foam can do wonders for pushing the water away from the house and it's easier to dig outside then inside.

I agree that an external perimeter drain is the way to go but it can't be safely done with a rubble foundation. The way those walls were made is by digging a bit pit, building up the wall a foot or so, filling in around it and then repeating until finished. The surrounding soil plays a structural role. You remove it from a wall that's decades old and there is a great chance of the whole thing buckling. Maybe you could do it one wall at a time and jack up the house above the wall from the inside an a bunch of places? I still wouldn't try it unless the whole house was being jacked up and a whole new foundation was being poured.
You could always go to a lumber yard and talk to their engineer to see what he thinks.

The floor of the basement is roughly 19'x27' with a 20" thick wall in the middle. So, square footage wise its really not very large.

I have definitely thought about digging down around the outside, perhaps only 2-3 ft down and putting in some foam against the wall, and perhaps a piece angled outward as I've seen you suggest before. However, I just haven't gotten to that yet.


Here is a layout of the basement, where things are and where the water problems are. As it says on the image, everywhere there is a water problem there is a crack(s) in the floor that the water comes up through. Even though the outside access seems like it might be the problem, it doesn't seem to be. I've had it covered up on the outside with metal roofing and it still gets water there in spring.

http://ecorenovator.org/forum/attach...1&d=1318774267

Having a stairway to the outside is going to make this whole project easier.
I suspect that what is happening at the bottom of the stairway is that water is fallowing the underside of the steps down, that the soil under the steps has settled and formed channels that are leading to the underside of your floor.
An easy way to figure out of this is the case is to expand the cover that covers that stairway, go out 4 feet or more around the outside of it and see if that helps next time we get rain.
Your platform that you are removing is also right next to one of your problem areas, so pulling out that section of floor could be done at the same time, cut in a trench and add drainage, that should be done at the bottom of a stairway like that anyway, with a small floor drain that leads to the sump pit to take care of water from the stairway.
I agree to a point about the stone foundation walls, on the other hand stone walls were often put up with a dirt floor and your current concrete floor could vary well be much newer then the rest of your house, still it would be a god idea to at least score a line with a masonry saw along the wall so you end up leaving the cement that is bonded to the wall.

Do you have efflorescence on any of your walls? What is the texture of your soils? (i.e. clay or sand) If your soils are clay I suspect that you have a seasonally high water table which is pretty commonplace in Spring in the Midwest. There also may be a drainage issue around the outside access, but that is probably only a secondary issue.

The stairway that comes down from inside the house has a landing at the bottom, can you see under that landing? I've seen a lot of basements (used to clean chimneys and have been in a lot of old houses) that have dirt under the landing because when the floor was poured it would have been even more work to pour the floor under the landing.

The landing is actually concrete. The wooden stairs just go down to it.

There is some efflorescence on the top of the wall in one spot or two, but really not much anywhere else that I have noticed. I'm not really sure of the texture of the soil.

Heres an update on the project. I started last weekend actually busting up the platform. I didn't get too far working on my own.

When we started today this is just about what we had. We started by cutting the concrete platform and cutting a trough where we will run the drain tiles.

http://ecorenovator.org/pictures/solar005.JPG

http://ecorenovator.org/pictures/solar006.JPG


We went and rented an electric hammer to break up the concrete.

http://ecorenovator.org/pictures/solar007.JPG



We only had it for four hours, but we were also able to make a hole in the wall for the solar piping.

http://ecorenovator.org/pictures/solar012.JPG

http://ecorenovator.org/pictures/solar011.JPG



Next up was digging out the trenches. This was tons of fun because it was mostly clay.

http://ecorenovator.org/pictures/solar008.JPG



Now it was finally time to lay down some rock and the drain tile.

http://ecorenovator.org/pictures/solar009.JPG

http://ecorenovator.org/pictures/solar010.JPG



Of course we ran into a wonderful snag. This is the floor drain plumbing. We're plumbing the drain tile into it. We were puzzled why it had a trap in it... It was completely plugged up full of gravel, so out it came. We ended up having to cut into the clay pipe it was attached to and we'll put in a new PVC floor drain and also run the drain tile to it.

http://ecorenovator.org/pictures/solar013.JPG

http://ecorenovator.org/pictures/solar014.JPG



So, this is the setup now. As you can see, we decided just to put the drain tile in the problem areas. This made things a TON easier, and it was still a lot of work.

http://ecorenovator.org/pictures/solar015.jpg

If you have not poured the new concrete yet, one thing that I found helps alot with bonding new concrete to old is to hammer drill some holes in to the old concrete and screw in some concrete screws (blue tapcons is what I have used) screwing these in half way gives the new cement something to bond to, you can also get adhesives that you mix with the wet cement and brush on the dry concrete to create a chemical bond as well.

Daox that's pretty heavy duty right there. How long did it all take you?

That last post was a days worth of work.

Today we poured the concrete for the drain tile, fixed some sump pump problems and also poured the new pad where the solar tank will be sitting along with some other miscellaneous things. I'll post pictures up later tonight.

Here are the pictures previously mentioned.


We got the new floor drain all situated and added the drain tile.
http://ecorenovator.org/pictures/solar016.JPG


Everything is prepped for concrete.
http://ecorenovator.org/pictures/solar017.JPG


Now for the concrete.
http://ecorenovator.org/pictures/solar018.JPG

http://ecorenovator.org/pictures/solar019.JPG


And then we did the larger pad area last.
http://ecorenovator.org/pictures/solar021.JPG

Well, this project was a bid success IMO. I hooked up my dehumidifer downstairs again the other day and turned it on to see how humid it was, and it read 60%. This is what I had it set to all summer long. Its also been quite wet lately (no huge downpours, just lots of light sprinkles keeping everything wet) so I know this is a worse than normal situation. Previously, without the dehumidifier it would pretty quickly get up to 80% humidity down there making it smell very musty and damp. The only big test left will be once spring rolls around. I think this will save me at least 1kWh/day in summer, plus not having to worry about cleaning up water downstairs.

You're one ambitious man.

I've had the unfortunate pleasure of dealing with water in the basement too these last two and a half months. My exception being 75% of the basement is finished.

I just finished all the drylok work in the basement, adjusted some grading around the problem wall and put the basement back together ~ 2 weeks ago after starting the adventure the end of August (new drywall, new carpet padding) to find a weak point in my system on Oct 28th... no power to the sump pump = water in the basement again. So, back up came the carpet, and I still have a LOT of spare padding from the last lay down, so, I'll put it back down again. Ordered a battery back up sump pump which is due to arrive today.

If I could have easily started over in the basement (no carpet, no drywall) I would have been doing the drain tile too, but, it was cheaper, faster, and easier to NOT toss out a ton of drywall and framing, and carpet, and dig up the floor. If it's ever under an inch of water, I may, but never has the floor ALL been wet at any given time.

Rehabbing a basement is not ECO Friendly :( Bags and bags and bags of trash. Plus as you mentioned... dehumidifiers, fans, etc running, and now that it's cold, added space heater to keep it from being COLD and damp.

It'll all be back together next week though. I'm a pro at drying things out now. And soon will be a pro carpet installer.

Sorry for slightly hijacking your thread....

Haha, no thread hijack at all. It wasn't quite as large of a project as I thought. Me, my father in law, and mother in law did it in two days approximately. It was only about 30ft of drain tile we put in, so relatilvely smal. Also, the outside access from the basement made things tons easier as we had to haul a lot of material in and out of the basement.

I finally got my first good test of the drainage system. This past weekend was very rainy. I'm not exactly sure how much rain we got, but it was a decent amount. Friday specifically we had a torential downpour with hail. When I got home from work I went to check the basement to see how the drain tile was holding up. I had one very small puddle in one area of the basement. It was gone the next day due to the now dry basement. If this is the worst it gets I'll be quite happy.

I'll probably hang on to the dehumidifier for a while longer, but it hasn't been plugged in since we did the work. In summer that means a good 1kWh less energy usage per day! My current average (with electric water heater) is 14-15 kWh/day so thats a solid 7% electric usage reduction all summer long.

You can gather a lot of water and let it seep down and in. This is kind of a pet peeve of mine, but you will often see "experts" on DIY television shows install a drain in a window well.