Adding interior drain tile to a basement

Daox · 10-15-11, 01:19 PM

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.

herlichka · 10-15-11, 02:57 PM

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!

Daox · 10-15-11, 03:21 PM

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.

herlichka · 10-15-11, 03:28 PM

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.

hamsterpower · 10-15-11, 03:36 PM

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.

S-F · 10-15-11, 03:53 PM

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.

RichInIL · 10-15-11, 08:39 PM

Quote:

Originally Posted by Daox

...So 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. ....

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.

...

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.

Ryland · 10-15-11, 10:12 PM

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.

S-F · 10-16-11, 09:52 AM

Quote:

Originally Posted by Ryland

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.

Daox · 10-16-11, 10:12 AM

Quote:

Originally Posted by Ryland

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.

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.

10-15-11, 03:21 PM	#3
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	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. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

10-15-11, 03:53 PM	#6
S-F You Ain't Me Join Date: Nov 2009 Location: Northampton MA Posts: 662 Thanks: 6 Thanked 71 Times in 58 Posts	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. Last edited by S-F; 10-15-11 at 03:58 PM..

10-15-11, 01:19 PM	#1
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	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. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Last edited by Daox; 10-24-11 at 10:59 AM..

10-15-11, 02:57 PM	#2
herlichka Apprentice EcoRenovator Join Date: Oct 2010 Location: Simcoe County, Ontario, Canada Posts: 102 Thanks: 11 Thanked 15 Times in 10 Posts	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! Last edited by herlichka; 10-15-11 at 03:09 PM.. Reason: Spelling

10-15-11, 03:28 PM	#4
herlichka Apprentice EcoRenovator Join Date: Oct 2010 Location: Simcoe County, Ontario, Canada Posts: 102 Thanks: 11 Thanked 15 Times in 10 Posts	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.

10-15-11, 03:36 PM	#5
hamsterpower Apprentice EcoRenovator Join Date: Oct 2009 Posts: 142 Thanks: 0 Thanked 11 Times in 11 Posts	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.

10-15-11, 10:12 PM	#8
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	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.