exterior foundation drain
#1
08-31-20, 10:11 PM
exterior foundation drain
can someone point me to a good source for info on removing water from foundation,
there is a lot of ground water under this house. It just keeps coming, doesn't have to have rained recently, there's like a spring underground or something.
There's no basement, house is on a slab with cinderblock foundation along the load bearing perimeter and probably cinderblocks in the middle under load bearing walls.
There's no basement sump pump to get this water to the street. Where I'd put the drainage pipe is below the level of the street, I'd like to run a pipe and send this water to the sewer. Need some sort of pop up or something?
I started digging around the house because crickets and the occasional mole were getting in, I mostly have to caulk the sill plate area, there were a few cracks in foundation near a 4" septic clean out and a large tree root (now removed) made a small crack somewhere. I started digging lower to make sure there were no deeper cracks in foundation where moles could get in.
Then I noticed at the corner the cinderblock is breaking away, and water was pouring out of holes/cracks in it, I'll pack it with hydraulic cement but I'm thinking having some weep holes is good to allow the water to escape.
I'm probably skipping the pipe on most of the house, probably not going to remove the paver patio etc for some areas probably aren't even needed, this is the very-wet side of the house.
#2
09-01-20, 12:05 AM
Member
You sure it's ground water and not coming from the downspout?
Basically you need to install a foundation drain tile, piping around the perimeter of he foundation, at the base of the foundation wall/block to direct the water away from the house.
Technically it's illigal to connect this type of drain to a sewer system!
Basically you need to install a foundation drain tile, piping around the perimeter of he foundation, at the base of the foundation wall/block to direct the water away from the house.
I'd like to run a pipe and send this water to the sewer
CasualJoe
voted this post useful.
#3
09-01-20, 10:18 AM
I find it hard to believe that's groundwater a few inches under the surface... If it were, your lawn would be a mushy mess.
Can you check your water meter? With all the faucets off in the house, do you see the little dial spinning?
Before going through the hassle of draining it, I would try to determine where it's coming from.
Can you check your water meter? With all the faucets off in the house, do you see the little dial spinning?
Before going through the hassle of draining it, I would try to determine where it's coming from.
CasualJoe
voted this post useful.
#4
09-04-20, 01:46 AM
I'd like to run a pipe and send this water to the sewer
Technically it's illigal to connect this type of drain to a sewer system!
sorry, I meant gutter, like many other houses, 4" hole through the curb.
I would actually utilize this water and have it go to shrubs/trees first instead and then excess would go to gutter but that whole side of the house IS always wet already. This pic is the back corner of the house and the whole way to the sidewalk is noticeably soggy.
yes that corroded hole is probably from the downspout making it worse, the least I would do is patch it, fill it back in and route it away from the foundation with a flex extension. And build up the grade along the house perimeter with clay-y soil.
That whole side of the house though is very wet underground, I dug up fence posts that it hadn't rained in weeks probably but there's like an underground river or something. Even google earth shows a blue line there as if it's a spring or something from no known source, and I dunno how they would know that it's so wet there maybe 43 years ago when they built the development they noted it and backfilled but it seems to be true.
Water was pissing out holes in the foundation yes mostly near that corner on the wet side but I guess there's also ground water coming up under the slab farther into the house.
The grade on that side doesn't slope towards the house much if at all.
There's a lot of sand in the soil for the first couple feet but then I'll sometimes hit very clay stuff deeper, so the clay could be like all hills and stuff under the sand and then water accumulates in areas not expected, like under the slab.
There's never been signs of moisture wicking up through the slab.
There is baseboard heat along the perimiter and copper pipe in the slab I think, but not sure how to see if it's leaking, plus I think we'd have seen water on the floor by now if it was.
If I do put a pipe, should I leave the weep holes (cracks)? and need some sort of popup or basin or something?
It's a 2 story house but yea I doubt it'll sink or something but I figure while I already have it dug out to add a flow pipe.
Basically you need to install a foundation drain tile, piping around the perimeter of he foundation, at the base of the foundation wall/block to direct the water away from the house.
But with a popup or basin? Do I really have to dig to footer? Not a problem if so but I'll research this more myself but figured I'd ask.
Technically it's illigal to connect this type of drain to a sewer system!
sorry, I meant gutter, like many other houses, 4" hole through the curb.
I would actually utilize this water and have it go to shrubs/trees first instead and then excess would go to gutter but that whole side of the house IS always wet already. This pic is the back corner of the house and the whole way to the sidewalk is noticeably soggy.
yes that corroded hole is probably from the downspout making it worse, the least I would do is patch it, fill it back in and route it away from the foundation with a flex extension. And build up the grade along the house perimeter with clay-y soil.
That whole side of the house though is very wet underground, I dug up fence posts that it hadn't rained in weeks probably but there's like an underground river or something. Even google earth shows a blue line there as if it's a spring or something from no known source, and I dunno how they would know that it's so wet there maybe 43 years ago when they built the development they noted it and backfilled but it seems to be true.
Water was pissing out holes in the foundation yes mostly near that corner on the wet side but I guess there's also ground water coming up under the slab farther into the house.
The grade on that side doesn't slope towards the house much if at all.
There's a lot of sand in the soil for the first couple feet but then I'll sometimes hit very clay stuff deeper, so the clay could be like all hills and stuff under the sand and then water accumulates in areas not expected, like under the slab.
There's never been signs of moisture wicking up through the slab.
There is baseboard heat along the perimiter and copper pipe in the slab I think, but not sure how to see if it's leaking, plus I think we'd have seen water on the floor by now if it was.
If I do put a pipe, should I leave the weep holes (cracks)? and need some sort of popup or basin or something?
It's a 2 story house but yea I doubt it'll sink or something but I figure while I already have it dug out to add a flow pipe.
Basically you need to install a foundation drain tile, piping around the perimeter of he foundation, at the base of the foundation wall/block to direct the water away from the house.
But with a popup or basin? Do I really have to dig to footer? Not a problem if so but I'll research this more myself but figured I'd ask.
#5
09-04-20, 05:22 AM
Member
Basically you need to install a foundation drain tile, piping around the perimeter of he foundation, at the base of the foundation wall/block to direct the water away from the house.
But with a popup or basin? Do I really have to dig to footer? Not a problem if so but I'll research this more myself but figured I'd ask.
But with a popup or basin? Do I really have to dig to footer? Not a problem if so but I'll research this more myself but figured I'd ask.
You need to dig a trench around the foundation, down to your footer, you stated it's a slab so lets assume a couple ft deep.
Lay perforated pipe and cover with pea gravel, that pipe will then work to remove all ground water away from the foundation.
Then install another dain line (solid pipe) to pick up all the water from the gutters, it could be tied into the first line as long as you have sufficient slope so it does not flow back to the foundation, or run it separately to discharge point in same trench.
Make sure you have sufficient slope 1/4" per foot min for both!
#6
09-04-20, 10:38 PM
^ I know, put ta pipe drainage system, but how do I get the water upwards? If I dig as deep as the footer or 3ft to below the frost line, I'll be lower than the street sewer level!
I guess the least I can do is connect the gutter to an underground pipe and lead that to the street or half way and it'll water bushes there, and build up a slope around the perimeter with clay soil, BUT I'm pretty sure there's ground water.
I guess the least I can do is connect the gutter to an underground pipe and lead that to the street or half way and it'll water bushes there, and build up a slope around the perimeter with clay soil, BUT I'm pretty sure there's ground water.
#7
09-05-20, 12:45 AM
Member
I'll be lower than the street sewer level!
#8
09-06-20, 05:30 PM
Good to know that it sounds like ground water. Well, I don't know if it's good... but I guess better than a leaking pipe.
Marq has you pretty well set up. If you can't get all the way down to the footer, the deeper the better. But if your locale allows you to drain out into the street, that's the best solution to get the water off your property. I don't like popup devices very much as it leaves the water in the pipe to freeze or get clogged. I'd much rather drain to air.
Marq has you pretty well set up. If you can't get all the way down to the footer, the deeper the better. But if your locale allows you to drain out into the street, that's the best solution to get the water off your property. I don't like popup devices very much as it leaves the water in the pipe to freeze or get clogged. I'd much rather drain to air.
#9
11-23-20, 08:16 PM
still haven't finished this..
question now:
remember this is the back corner of the house.
Want to send the water to the front yard.
The back yard away from the house already gets flooded too because it's like a valley between the back property line and the house when they graded the earth.
This side of house is much wetter than the other side. I always noticed after rain/days the sidewalk on this side was still wet and grass saturated but not the other side. I dig along the other side of foundation too, not very deep, just enough to parge/skim coat so it matches the new on this side and just to fit a caulk gun into sill plate area where bugs/moles might get in. But is seems perfectly dry on that side, and same for after it rains. It's not simply roof/gutter discharge amount because the dry side gets almost the same amount of roof area downspouted to it.
I'll check the water meter dial thing suggested but I don't think there's a leaking pipe.
So anyway, suppose the street level or any lower area in the front yard is only a few inches lower than where the top of these foundation blocks are. Then I would only be able to put the perforated french drain like 8" inches below the sill plate, so is that even worth it?
I'll connect gutter to a discharge pipe, but it seems all rain water is seeping into the earth and would make its way under such a shallow french drain.
What I did so far was dug all around the foundation (shallow in most areas) just to make sure there were no bad spots like this or holes made from tree roots, then powerwashed it in prep to patch this area shown and some other bad spots.
After powerwashing and some scraping it's much worse than the pics, it's hollow black block and all pitted and crumbling in the corner problem area. Yes it could be the downspout is right there and wasn't diverted but also as mentioned such a soggy side of house.
Next I'm skim coating/parging the whole foundation (so even the non problem areas match and look good too) with Type s Mortar, Adding more Hydrated Lime to the mix sounded good at first because a) lime makes cement more flexible and less cracks and less with freeze/thaw, and makes it more waterproof, but I'm thinking waterproofing the outside of this wall (or imagine using black rubber membrane) isn't a good idea because I'm pretty sure water is getting Under the footer anyway and would get trapped in the wall and make it worse, But I do have to patch it with something because it's all crumbling in areas, so regular Type S mortar I'll use, maybe add even more sand come to think of it so it can breathe a bit more.
question now:
remember this is the back corner of the house.
Want to send the water to the front yard.
The back yard away from the house already gets flooded too because it's like a valley between the back property line and the house when they graded the earth.
This side of house is much wetter than the other side. I always noticed after rain/days the sidewalk on this side was still wet and grass saturated but not the other side. I dig along the other side of foundation too, not very deep, just enough to parge/skim coat so it matches the new on this side and just to fit a caulk gun into sill plate area where bugs/moles might get in. But is seems perfectly dry on that side, and same for after it rains. It's not simply roof/gutter discharge amount because the dry side gets almost the same amount of roof area downspouted to it.
I'll check the water meter dial thing suggested but I don't think there's a leaking pipe.
So anyway, suppose the street level or any lower area in the front yard is only a few inches lower than where the top of these foundation blocks are. Then I would only be able to put the perforated french drain like 8" inches below the sill plate, so is that even worth it?
I'll connect gutter to a discharge pipe, but it seems all rain water is seeping into the earth and would make its way under such a shallow french drain.
What I did so far was dug all around the foundation (shallow in most areas) just to make sure there were no bad spots like this or holes made from tree roots, then powerwashed it in prep to patch this area shown and some other bad spots.
After powerwashing and some scraping it's much worse than the pics, it's hollow black block and all pitted and crumbling in the corner problem area. Yes it could be the downspout is right there and wasn't diverted but also as mentioned such a soggy side of house.
Next I'm skim coating/parging the whole foundation (so even the non problem areas match and look good too) with Type s Mortar, Adding more Hydrated Lime to the mix sounded good at first because a) lime makes cement more flexible and less cracks and less with freeze/thaw, and makes it more waterproof, but I'm thinking waterproofing the outside of this wall (or imagine using black rubber membrane) isn't a good idea because I'm pretty sure water is getting Under the footer anyway and would get trapped in the wall and make it worse, But I do have to patch it with something because it's all crumbling in areas, so regular Type S mortar I'll use, maybe add even more sand come to think of it so it can breathe a bit more.
#10
11-23-20, 11:25 PM
Member
it's like a valley between the back property line and the house when they graded the earth.
This side of house is much wetter than the other side. I always noticed after rain/days the sidewalk on this side was still wet and grass saturated but not the other side
#11
11-24-20, 04:49 AM
The ground surface needs to slope away from the house on all 4 sides. Regrade it if needed.
You do not have a prayer of solving he problem if water accumulates against the foundation.
A perforated perimeter drain (a kind of French drain) around a house on a slab can be as close as 12 inches below the surface in warmer climates. But all French drains need a destination for the water and this is usually a pit with a sump pump.
In most cases the peforated perimeter drain pipe cannot have much slope. You may not excavate below the bottoms of the foundation footings when laying the drain pipe along the foundation..
Sometimes a temporary pit with sump pump perhaps 8 feet away from the foundation is needed to drain the trench you are digging to install your perimeter drain. One of these pits can conceivably become a permanant place for a sump pump.
You do not have a prayer of solving he problem if water accumulates against the foundation.
A perforated perimeter drain (a kind of French drain) around a house on a slab can be as close as 12 inches below the surface in warmer climates. But all French drains need a destination for the water and this is usually a pit with a sump pump.
In most cases the peforated perimeter drain pipe cannot have much slope. You may not excavate below the bottoms of the foundation footings when laying the drain pipe along the foundation..
Sometimes a temporary pit with sump pump perhaps 8 feet away from the foundation is needed to drain the trench you are digging to install your perimeter drain. One of these pits can conceivably become a permanant place for a sump pump.
Last edited by AllanJ; 11-24-20 at 05:07 AM.
#12
01-25-21, 11:15 PM
Hopefully I got this solved, there WAS a plumbing leak, a rather major one going for who knows how long, likely years, amazing there was no sign of this under the kitchen sink which is frequented for dish soap etc. I simply replacing the P trap because the washers went bad, was all done and then noticed drywall under there looked soft and I pressed through it like nothing and pulled it all, insulation was soaked.
When they built the home, that pipe is slightly off level, and tilted back the wrong way, so water was sitting in the 90 degree copper (brass?) elbow that connects the horizontal discharge pipe along wall to the P trap. Plenty of other brass/copper elbows/P traps in home that have standing water in them but no leaks, I guess because this is the sink and so much stuff has been washed down it over time (cleaners, a little bit of extra paint thinner or something, etc) that it corroded a hole.
The insulation kept it from being noticed or splashing or anything, with the insulation removed and running the sink it leaks really bad, maybe 10 gallons a day possibly, basically it leaks as much as if you took a regular small-cap poland spring bottle and put your finger over 2/3 of the opening and turned it upside down, the other 1/3 is how much this leaks.
It leaks right down into the hollow cement block foundation and then to the footer where as mentioned it was always holding water which I though was ground water knowing how much the yard can flood after rain and knowing how much water I've found 3 feet down digging fence posts 25 feet from there and finding basically an underground river weeks after it hadn't rained.
Will have the plumbing leak all fixed tomorrow. Bleached and heater drying now. Will get the pipe tilted the right way.
Then will dig down foundation in a few spots after it rains (and to be fair considering the grading of the yard will check a day or 3 after it rains and then really shouldn't see any water) to hopefully not see any water from rain which would warrant a french drain which might have to go uphill as mentioned isn't standard.
Before noticing this leak, my plan was to check if I could even get a french drain ran to the street without it having to go uphill or using an exterior sump pump. Despite mentioning that it would have to go uphill to do that, I'm not sure, it's close, will run a string level line (I know they're not the best but I'm not gonna get a laser just for this) and string from the street to the foundation corner and then see if I can get about 4 feet lower than grade to get the pipe to the bottom of the footer and hopefully have about an extra 8 inches lower grade at the street so the water actually flows to there, it's about a 50 foot run which is supposed to be about 5 inches slope but I'd rather play it safe a go a couple inches more if even possible at all. If the street is uphill, I was going to maybe just get the pipe as deep as I could along the foundation so it would at least get the water out once it raises to a certain level. Need to bring in some soil anyway and fix the grading too a bit, and permanently route the downspout away from the foundation.
The corner damage shown is likely from grading of the yard, and this leak which IDK how long it's been leaking (sill plates and studs are surprisingly still solid even with wet insulation around them despite most of the leak runs straight down into the hollow blocks) but also mostly from gutter downspout not being diverted, since that was the worst area of the foundation.
BTW, there is a guy I found who puts EXTERIOR sump pumps in freezing Michigan, in case grading isn't in your favor to run it downhill, all he uses is a plug-in heat tape lol, some people questioned this in comments. it doesn't seem correct to just wrap heat tape around the pipe and submerged it water. I'm not sure, they do make ones for gutters to melt ice but a quick google says: "Can heat tape be submerged in water?
Available with housing styles that are resistant to water and many chemicals, and suitable for outdoor use. Some styles are resistant to moisture or suitable for use on electrically conductive surfaces, but they must not be submerged, and are generally intended for indoor applications."
It does work apparently it gives enough heat and I found one video where he mentioned specs of a newer one he started using was higher than previous ones he's installed as if the previous ones weren't good enough), he's the only example of exterior sump pump with freeze protection I could find. I can't find the exact video where he mentions it's just heater tape or possibly showed it, and he's got a ton of vids I tried sifting through and couldn't find those ones easily, but here are some other example videos.
IMHO this guy goes overkill with the french drains and catch basins, these systems likely need maintenance and I think some yards he's done all they needed was to bring in a bunch of topsoil and really regrade the yard good, probably like $20K+ less and no catch basins in the way or maintenance, but anyway:
https://www.youtube.com/watch?v=gA1SrJP94Xw
https://youtu.be/Au6aGoC9E2o?t=3574
https://www.youtube.com/watch?v=JVDPOZy7nVU
When they built the home, that pipe is slightly off level, and tilted back the wrong way, so water was sitting in the 90 degree copper (brass?) elbow that connects the horizontal discharge pipe along wall to the P trap. Plenty of other brass/copper elbows/P traps in home that have standing water in them but no leaks, I guess because this is the sink and so much stuff has been washed down it over time (cleaners, a little bit of extra paint thinner or something, etc) that it corroded a hole.
The insulation kept it from being noticed or splashing or anything, with the insulation removed and running the sink it leaks really bad, maybe 10 gallons a day possibly, basically it leaks as much as if you took a regular small-cap poland spring bottle and put your finger over 2/3 of the opening and turned it upside down, the other 1/3 is how much this leaks.
It leaks right down into the hollow cement block foundation and then to the footer where as mentioned it was always holding water which I though was ground water knowing how much the yard can flood after rain and knowing how much water I've found 3 feet down digging fence posts 25 feet from there and finding basically an underground river weeks after it hadn't rained.
Will have the plumbing leak all fixed tomorrow. Bleached and heater drying now. Will get the pipe tilted the right way.
Then will dig down foundation in a few spots after it rains (and to be fair considering the grading of the yard will check a day or 3 after it rains and then really shouldn't see any water) to hopefully not see any water from rain which would warrant a french drain which might have to go uphill as mentioned isn't standard.
Before noticing this leak, my plan was to check if I could even get a french drain ran to the street without it having to go uphill or using an exterior sump pump. Despite mentioning that it would have to go uphill to do that, I'm not sure, it's close, will run a string level line (I know they're not the best but I'm not gonna get a laser just for this) and string from the street to the foundation corner and then see if I can get about 4 feet lower than grade to get the pipe to the bottom of the footer and hopefully have about an extra 8 inches lower grade at the street so the water actually flows to there, it's about a 50 foot run which is supposed to be about 5 inches slope but I'd rather play it safe a go a couple inches more if even possible at all. If the street is uphill, I was going to maybe just get the pipe as deep as I could along the foundation so it would at least get the water out once it raises to a certain level. Need to bring in some soil anyway and fix the grading too a bit, and permanently route the downspout away from the foundation.
The corner damage shown is likely from grading of the yard, and this leak which IDK how long it's been leaking (sill plates and studs are surprisingly still solid even with wet insulation around them despite most of the leak runs straight down into the hollow blocks) but also mostly from gutter downspout not being diverted, since that was the worst area of the foundation.
BTW, there is a guy I found who puts EXTERIOR sump pumps in freezing Michigan, in case grading isn't in your favor to run it downhill, all he uses is a plug-in heat tape lol, some people questioned this in comments. it doesn't seem correct to just wrap heat tape around the pipe and submerged it water. I'm not sure, they do make ones for gutters to melt ice but a quick google says: "Can heat tape be submerged in water?
Available with housing styles that are resistant to water and many chemicals, and suitable for outdoor use. Some styles are resistant to moisture or suitable for use on electrically conductive surfaces, but they must not be submerged, and are generally intended for indoor applications."
It does work apparently it gives enough heat and I found one video where he mentioned specs of a newer one he started using was higher than previous ones he's installed as if the previous ones weren't good enough), he's the only example of exterior sump pump with freeze protection I could find. I can't find the exact video where he mentions it's just heater tape or possibly showed it, and he's got a ton of vids I tried sifting through and couldn't find those ones easily, but here are some other example videos.
IMHO this guy goes overkill with the french drains and catch basins, these systems likely need maintenance and I think some yards he's done all they needed was to bring in a bunch of topsoil and really regrade the yard good, probably like $20K+ less and no catch basins in the way or maintenance, but anyway:
https://www.youtube.com/watch?v=gA1SrJP94Xw
https://youtu.be/Au6aGoC9E2o?t=3574
https://www.youtube.com/watch?v=JVDPOZy7nVU
