Author Topic: interior french drain  (Read 1882 times)

Case

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interior french drain
« on: February 05, 2020, 04:03:28 PM »
I had some rain in the basement due to recent heavy storms.  Basically out of luck I noticed the water in the unfinished utility closet, but the rest of my basement is finished.  After pulling back carpet, it looks like water leaks in in a couple locations.  It is usually very little water... so little that I never noticed in a year living here (it gets under the carpet at the edge of the wall, but not enough to actually make the carpet wet (no mold)... just enough that you see it dripping in.  However, when we have heavy record breaking rains, it came in a bit more and we contained it with towels (periodically replacing them).  Our house is on a hill, and he backyard goes slightly uphill on one side.  This side develops standing water when it rains.

Our basement is fully finished, and it's important for re-sale that we keep it nice and protected from the water.
There are a few options:
1.  Do nothing, until we get rains heavy enough that actual water damage occurs, if it ever does.
2.  Have a shallow french drain installed in the backyard to redirect surface water.
3.  Have one of those interior french drain systems installed (e.g. dig up the concrete around the perimeter of the floor, add install drain pipe, weep holes in the concrete block foundation, seal, refinish).

Option 1 is probably a no go unless the upcoming Noreaster causes no water in the basement.  This seems unlikely, as I'd rather have peace of mind even if it costs some thousands of dollars.

Option 2 is a maybe, but basically, I try it out, and if it works great, but there is a chance it wont fix it (e.g. groundwater problem) and then I likely have to go with option 3.

Option 3 was proposed by a contractor, and he proposed we just do it on the sides of the basement with water problems.  I'm not sure of the cost of Option 2, but Option 3 was not too expensive, and Option 3 is guaranteed to fix the problem (both logically and guaranteed by the contractor).  Unless water starts to come in on the other parts of the basement, but it seems unlikely this would happen.  Quote was for $3800 for 64 linear ft of drain, including sump installation.  Price will go up slightly if I get a battery back up pump, which I will.

Any thoughts?  I know that these interior systems are controversial, but an exterior system is an nearly impossible for reasons I wont go into.

For people that have had interior french drains installed, what was your experience?  Any things to watch out for?

Btw, this is not DIY, but I figured the DIY crowd would be more knowledgeable..  i can move the post if inappropriate.



Update  2-15-2020:

Here are some images that illustrate my house and hopefully better explain the water situation.  The house is on a hill which slopes significantly down my front lawn.  That same front lawn contains a septic leech field.  This is an important detail as it my be make the ground in the front of my house saturated with water.  In addition to the back-to-front slope of my property, there is a right-to left slope along the street I am on (water slows down street when going right to left, when facing the house). 

My back yard is mostly flat.  However, my neighbor to right of me (when facing house front) is uphill, and the swail between our houses becomes extremely wet due to my neighbor's downspouts, as well as my own downspouts (yellow in picture) and such.  The swail directs water out to the street, but I wonder if this water goes under the garage and down to the basement side. In this location, I am considering installing a shallow french drain to route the water out to the street.

The backyard till become very saturated and with heavy rains, developing standing water.  This occurred especially at the down spout in the middle back of my house, as well as the back of my garage which had clogged gutters at the time (obviously I will never let them clog again).  It is more difficult to imagine how to french drain this water away.  I would tie it into a french drain on the right side.  However, the left side of the house is very narrow, and it would be a little tricky to pipe the water away due to the septic tank system which is in the way (red). 

To the left of my house (when viewed from front) is my other neighbor.  I probably want to avoid dumping water on this side of the property.  Where my property ends there is a 4 foot drop to my neighbors property, and so water would certainly accumulate on his property.

Water came in the basement at two locations (shown in blue).  In both cases it was a gradual leak which was slow enough to be contained with towels.

1.  the front of the basement, directly underneath my patio (which has a roof and slab).  This is where I suspect the leech field may have contributed.  The previous day I ran tub + several faucets for about an hour (long story) which means tons of water went into the leech field.

2.  The back corner of the basement, which is underneath the garage as well as the back patio.  Presumably my clogged gutters contributed here.  Also, the saturated swail on the right side of the house may have contributed.



Things I am considering doing:
1.  Installing surface french drains on the right swail to get rid of the surface water there.
2.  Installing surface french drains in the backyard, but not certain where these will deposit water.
3.  Pulling out the drywall at the problem locations, to better see what is going on at the wall (presumably cracks).
4.  Installing a water barrier in my garden beds to direct water away from my house walls.
5.  Have a contractor install an interior french drain system (under the slab).

Hopefully I don't need to do everything there, as it is some combination of a shit-ton of work, or expensive (how much I hire out). 

I can try the various steps that don't include an interior system, as most here have suggested.  The main issue is that, the only way to know if my efforts will work is to see what happens the next time we have an epic rainfall event.  If the steps dont work, then my basement could get water damage, and it was all for nought.  The interior system at least is an insurance plan, and might be attractive to future buyers when I sell some day.  But, I certainly would not do an interior system only.  I almost certainly am installing a shallow French drain to re-route as much surface water as I can.

If you made it this far, thank you for reading!  Any comments/thoughts are welcome.
« Last Edit: February 15, 2020, 02:38:56 PM by Case »

lthenderson

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Re: interior french drain
« Reply #1 on: February 06, 2020, 07:07:35 AM »
If it were my house, the only option would be to stop the water from getting into the house. Dealing with the water once it enters the house is a bandaid fix and can potentially allow more damage to occur to the house. If the water is leaking through or touching wood, it rots with time. If water is leaking through concrete in an environment that gets below freezing, ice can heave and widen cracks causing buckling issues. Even if the water isn't damaging the house structure, it is making the environment unnecessarily more humid in the summer which increases energy bills, creates a potential for mold and lowers resale value.

Jon Bon

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Re: interior french drain
« Reply #2 on: February 06, 2020, 10:32:52 AM »
I feel like I need to have a copy and paste answer to this one.

Go stand outside your house in a rain storm. Seriously. Find what the water is doing, find where its pooling find where its overwhelming your existing gutters and downspouts.  You dont need basement water proofing, you need to clean your gutters and downspouts. You need to make sure your gutter discharge is far from your house. You need to check your grading and look for negative slope and valleys.

Basement water problems are almost always problems with gutters and grading.  #2 might work, #3 likely wont work.

Good luck and let us know how it goes.


index

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Re: interior french drain
« Reply #3 on: February 06, 2020, 11:58:02 AM »
I feel like I need to have a copy and paste answer to this one.

Go stand outside your house in a rain storm. Seriously. Find what the water is doing, find where its pooling find where its overwhelming your existing gutters and downspouts.  You dont need basement water proofing, you need to clean your gutters and downspouts. You need to make sure your gutter discharge is far from your house. You need to check your grading and look for negative slope and valleys.

Basement water problems are almost always problems with gutters and grading.  #2 might work, #3 likely wont work.

Good luck and let us know how it goes.

Listen to this guy. It's not a groundwater issue, its surface water. The contractor is trying to make $60/ft.

Case

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Re: interior french drain
« Reply #4 on: February 06, 2020, 02:10:40 PM »
If it were my house, the only option would be to stop the water from getting into the house. Dealing with the water once it enters the house is a bandaid fix and can potentially allow more damage to occur to the house. If the water is leaking through or touching wood, it rots with time. If water is leaking through concrete in an environment that gets below freezing, ice can heave and widen cracks causing buckling issues. Even if the water isn't damaging the house structure, it is making the environment unnecessarily more humid in the summer which increases energy bills, creates a potential for mold and lowers resale value.

I agree, with the caveat that it may not be possible to stop a high water table.  I can try things like installing french drains to re-route surface water, extending downspouts, etc... but the problem with old houses that don't have exterior french drains around the footers is that a high water table will result in water in the basement.  But I agree, there potentially could be water that weakens the cinder block and foundation.

Case

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Re: interior french drain
« Reply #5 on: February 06, 2020, 02:17:21 PM »
I feel like I need to have a copy and paste answer to this one.

Go stand outside your house in a rain storm. Seriously. Find what the water is doing, find where its pooling find where its overwhelming your existing gutters and downspouts.  You dont need basement water proofing, you need to clean your gutters and downspouts. You need to make sure your gutter discharge is far from your house. You need to check your grading and look for negative slope and valleys.

Basement water problems are almost always problems with gutters and grading.  #2 might work, #3 likely wont work.

Good luck and let us know how it goes.

One of the problem spots are the downspouts next to the garage.  This area gets very soggy.  It is ~25 ft from the wall of the basement, but perhaps the water goes under the garage and ends up at the basement.  I can fix this with extended downspouts and a french drain.

On the other side of the house, the problem is less clear.  The front side of my house faces a steep hill (my front lawn).  Yet, this area gets some water.  In fact, the place where water comes in is directly underneath a large patio slab which extends ~5 feet beyond the house.  My only guess as to what allows water here is that our front lawn is a septic leech field and perhaps this keeps the soil wet (combine that with heavy rains...). 

Papa bear

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Re: interior french drain
« Reply #6 on: February 06, 2020, 02:41:23 PM »
If it were my house, the only option would be to stop the water from getting into the house. Dealing with the water once it enters the house is a bandaid fix and can potentially allow more damage to occur to the house. If the water is leaking through or touching wood, it rots with time. If water is leaking through concrete in an environment that gets below freezing, ice can heave and widen cracks causing buckling issues. Even if the water isn't damaging the house structure, it is making the environment unnecessarily more humid in the summer which increases energy bills, creates a potential for mold and lowers resale value.
This.


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Papa bear

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Re: interior french drain
« Reply #7 on: February 06, 2020, 02:42:52 PM »
I feel like I need to have a copy and paste answer to this one.

Go stand outside your house in a rain storm. Seriously. Find what the water is doing, find where its pooling find where its overwhelming your existing gutters and downspouts.  You dont need basement water proofing, you need to clean your gutters and downspouts. You need to make sure your gutter discharge is far from your house. You need to check your grading and look for negative slope and valleys.

Basement water problems are almost always problems with gutters and grading.  #2 might work, #3 likely wont work.

Good luck and let us know how it goes.


AND this.

I swear we all have posts to this from over the years.

Look up. Then work your way down. An interior french drain with a sump pump is the LAST option.

Check to make sure your concrete pad is grading away from your house as well. 


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Sanitary Engineer

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Re: interior french drain
« Reply #8 on: February 06, 2020, 03:02:08 PM »
It may be that your large patio slab sits on some crushed stone which is the easiest path for water coming off your house to take and puts the water against your foundation.  I assume the steep hill is sloping away from your house on the front side, maybe you can install a piped french drain around the patio and daylight it on that slope.

Does the ground freeze where you are my basement problems usually only manifest when significant thawing is occuring.

On the side sloping toward your house, you should try to determine where seasonal high groundwater table is through a soil test pit.  I tend to agree with Jon Bon that managing water on the surface is the best place to start, this is definitely the issue at my house.  However, I have installed some footing drains at buildings dealing with groundwater and no amount of grading or 4 foot deep french drain was going to solve the water issue, we needed to get right down to the ledge and run a pipe to daylight.  If you are dealing with groundwater than an exterior footing drain makes the most sense to me.  I don't trust sump pumps in living spaces.  If I saw a sump pump in a finished basement space I would be very wary.

Case

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Re: interior french drain
« Reply #9 on: February 06, 2020, 03:49:19 PM »
It may be that your large patio slab sits on some crushed stone which is the easiest path for water coming off your house to take and puts the water against your foundation.  I assume the steep hill is sloping away from your house on the front side, maybe you can install a piped french drain around the patio and daylight it on that slope.

Does the ground freeze where you are my basement problems usually only manifest when significant thawing is occuring.

On the side sloping toward your house, you should try to determine where seasonal high groundwater table is through a soil test pit.  I tend to agree with Jon Bon that managing water on the surface is the best place to start, this is definitely the issue at my house.  However, I have installed some footing drains at buildings dealing with groundwater and no amount of grading or 4 foot deep french drain was going to solve the water issue, we needed to get right down to the ledge and run a pipe to daylight.  If you are dealing with groundwater than an exterior footing drain makes the most sense to me.  I don't trust sump pumps in living spaces.  If I saw a sump pump in a finished basement space I would be very wary.

Thanks, that is a very interesting idea (crushed stone below the patio which is easy to permeate.  Actually, the back of the house where water is also coming in, also has a patio.

Per freezing, we are in northern Delaware.  There may have been a thaw at the time.  The temperatures did jump up from upper 20s to 40s or 50s with the heavy rains... of course, this has been a pretty warm 'winter' and I'm not sure if the ground has frozen very much and if so how deep. 

Why don't you trust sump pumps?  I would actually be leery of any house (in a non-dry climate) that doesn't have one.

Sanitary Engineer

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Re: interior french drain
« Reply #10 on: February 07, 2020, 06:54:15 AM »
I am not against them in unfinished spaces, when used with a dehumidifier. They are better than a wet basement.  But they generally mean there is no foundation drain around the footing, which is the ideal situation.

They are usually very cheap pumps with cheap control switches that are prone to failure, they are high in maintenance requirements. If you want them to work when they need to work you need to regularly check that they are working and repair them when they aren't (not something I am likley to do).  They indicate water is coming in and, if there are finishes nearby, then there is a good chance those finishes are growing mold on their moist dark interiors.


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Re: interior french drain
« Reply #11 on: February 07, 2020, 07:58:32 AM »
If it were my house, the only option would be to stop the water from getting into the house. Dealing with the water once it enters the house is a bandaid fix and can potentially allow more damage to occur to the house. If the water is leaking through or touching wood, it rots with time. If water is leaking through concrete in an environment that gets below freezing, ice can heave and widen cracks causing buckling issues. Even if the water isn't damaging the house structure, it is making the environment unnecessarily more humid in the summer which increases energy bills, creates a potential for mold and lowers resale value.

I agree, with the caveat that it may not be possible to stop a high water table.  I can try things like installing french drains to re-route surface water, extending downspouts, etc... but the problem with old houses that don't have exterior french drains around the footers is that a high water table will result in water in the basement.  But I agree, there potentially could be water that weakens the cinder block and foundation.

It's not ground water if you are only getting water in when it is raining.

Sanitary Engineer

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Re: interior french drain
« Reply #12 on: February 07, 2020, 08:00:52 AM »

It's not ground water if you are only getting water in when it is raining.

+1 This is smart.

lutorm

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Re: interior french drain
« Reply #13 on: February 09, 2020, 10:09:27 PM »
I did a big project digging a trench around the exterior of our house and putting in a drain pipe a couple of years ago after we got water in the basement after a big rain. The house sits on a rocky slope and when it rains heavily water flows on top of the rock a few feet under the surface and pools against the house, sounds like a situation similar to yours? After putting in the drains, and ensuring the downspouts all discharge down below the house, water has not returned. Some of the concrete is still moist, but I think that's more a symptom of shitty, porous concrete at this point.

I agree with the other posters that you want to a) prevent the water from entering in the first place, and b) want the water to drain passively. You didn't go into the reasons why an exterior system is "nearly impossible".

dneck37

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Re: interior french drain
« Reply #14 on: February 10, 2020, 09:12:48 AM »
Like others have said this is most likely not a ground water issue. Not ground water if it only happens when it rains or is not coming up in the lowest part of your basement. I would try at all costs to deal with the water outside first. Attack the gutters, clean them out and route them all away from your house downhill. If this isnt possible, route the downspouts to corrugated black pipe(non perforated) away from the house to the end of your property(but not at a neighbors home, unless you are actively trying to make their life hell). If this doesnt work go out in the rain and figure out where water is flowing and pooling too. Install a drain here and tie it in to your gutter pipes to get it away from your house. If all this fails then you need an interior french drain with a sump pump. Installing this yourself SSSSUUUUUUUUUUCCCCCCCCCCCCKKKKKKKSSSSSSSSSSS! I did it because I'm a cheapass and my wife and I arent afraid of a ridiculous amount of manual labor. Warning if you choose this option it will consume until you are finished. Keep us posted on ur solutions I wish you luck! If you have to go with the dreaded third option let us know and I can post my playbook for the project. Contractor quoted it at $15k with 2 sump pumps, I did it for $2500, one beast sump pump, and cashing in all my accumulated favors from friends.

wienerdog

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Re: interior french drain
« Reply #15 on: February 11, 2020, 11:43:32 AM »
If you have to go with the dreaded third option let us know and I can post my playbook for the project. Contractor quoted it at $15k with 2 sump pumps, I did it for $2500, one beast sump pump, and cashing in all my accumulated favors from friends.

My house has ground water that comes up through the cracks.  I wouldn't mind seeing what you did.  I have a well and I have measured the water level compared to the basement floor.  The water table is only 12" or so below the basement floor.  I do have a natural drain that goes out of the back of the basement as the creek is 6 feet or so below the basement floor out the back of the property.

dneck37

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Re: interior french drain
« Reply #16 on: February 12, 2020, 12:19:17 PM »
My house has ground water that comes up through the cracks.  I wouldn't mind seeing what you did.  I have a well and I have measured the water level compared to the basement floor.  The water table is only 12" or so below the basement floor.  I do have a natural drain that goes out of the back of the basement as the creek is 6 feet or so below the basement floor out the back of the property.
[/quote]


Sounds like you got a lot going on there wienerdog.

Below is step by step for my interior french drain solution. I can not stress this enough this is a last line of defense option.

1. Determine lowest point in the basement. This is where you will need to place your new sump pump basin.
2. Map out your interior basement and determine where all drain lines will run as well as your exit strategy for water. I broke out one of my basement windows and sent the water out through there. I have 2.5 ft thick poured concrete walls in my basement (1922 was a crazy time). Note: check your local codes but I believe most states in the US do not allow you to pump it into your sewer line. The utilities don't want to clean the "clean" ground water again.
3. Figure out if you can generate enough pitch to flow water to your new sump. I used 1/8th inch slope per foot. To figure out the pitch space needed take the run length in ft of one proposed branch of drain pipe and multiply by 1/8 and 1/12. This will give u inches of top from start to finish needed. Add 6 inches for total in ground depth(atleast 3 inches of gravel and 3 inches of new concrete will go over the top of this drain pipe).  For example 100 feet of drain pipe away from sump would be (100x(1/8)x(1/12))+0.5=1.541 ft of depth. Some people will say this is overkill (which it may be) but its what i did and i had success. If you want to get real fancy you can factor in the pitch of your floor but to keep it simple I stayed out of that.
4. Try to find a sump pump basin that is 4 inches deeper than your depth. If you cant get anywhere near this than you may need to shorten drain line runs by adding an additional sump pump or move the sump to a more central location. 
5. Purchase basin kit, check valve, sump pump, and battery backup sump pump kit. Note: buy the best sump pump you can find especially if you have to pump vertically more than a few feet. I got a liberty aluminum pump (no rusting) with 1/2 hp, the thing is a beast. Also if ur ever going to put in a battery back up do it now. It only gets harder in the future.
6. Drill holes in sump basin. Make that thing look like swiss cheese. Seriously drill as many holes as possible without over weakening the basin to where it might crack. Also drill in holes for entry of drain lines. Attach a small run of drain line(I used 3 feet of 3 inch perforated corrugated black pipe) to each entry hole.
7.Plumb the sump pumps and backups so they are ready to drop in.
8. Execute your water exit strategy. Example drill your exterior wall to fit a 1.5 inch pvc pipe. Insert the pipe and run to desired area downhill from your home atleast 20 ft. Do not do any additional plumbing inside home. Just have it ready to connect to your sump pump once your sump pump is in.
9. Measure and chalk line off a square for sump basin area and at least the first 3 ft of the beginning of your drain line path. I would suggest making a square twice the diameter of your sump basin. Bigger is better though. The drain line path should be at least 1.5 ft wide. It depends on you footer though, and you will not be able to determine that until you start digging.
10. Cut floor with concrete saw and break concrete with hammer or jack hammer.
11. Remove concrete and dig out the square to a depth of the sump basin plus 6 inches. You will begin to see ground water during this. You have a couple strategies to deal with it. Bucket out the water, just power through the water being there, or temporarily set up sump pump basin and drop it in every so often to drain out excess water (super dirty water isn't great for your pump so make sure it is in the basin when u drop it in. This will prevent it from sucking up rocks.
12. Also make sure you dig out the beginning of your drain line path. You will want to find the bottom of your footer. You should see gravel when you get to it, if not dig another 3 inches deeper next to (not under) the footer and add gravel.
13. Once you have gotten to the target depth fill the sump basin area with 6 inches with clean gravel and drop in the sump basin. Fit the sump drain line entrance pipes in next to your footer. Cap the ends so they do not fill with gravel. place a thin heavy cement paver in the bottom of the basin to ensure it stays put while you back fill around it with gravel.
14. Drop in you plumbed sump and hook up to our water exit pipe. I believe doing all this first is best because if you have a true ground water problem all the trenches you dig will fill with water while digging making it a major pain in the ass. With the sump in place it with help to keep the water level down while you work on the rest of your project.
15. By now you should have determined where your footer is so you can establish a drain line path width. I would use atleast 1.5 feet as long as you have 7 inches of space from your footer(3 inches for drain pipe and 4 inches for clean gravel. Meaning if your footer extended in 11 inches from the wall you would need to have a total drain line path with of 18 inches. With this new dimension chalk out your drain line path and cut with a concrete saw preferable with a hose attachment to keep the dust down. Cut atleast 2 inches in depth. More is better as it will lower the risk for cracking when you are breaking it out.
16. Go back and now make a cut inside the drain path perpendicular to the path every 8 to 12 inches(making it look like sidewalk tiles). This will make breaking concrete in the specific place you want easier.
17. Break all concrete with jack hammer and haul out to concrete recycling area.
18. Dig all drain line trenches to the depth number you determined above plus 3 inches. You need atleast 3 inches of clean gravel under the drain line. This will be the longest step in the whole process. Just soldier though it there with be an end to the digging at some point.
19. Fill all trenches with 3 inches of clean gravel.
20. Start installing drain pipe. Wrap pipe in drain pipe cloth to prevent any solids from entering the pipe. Work back from sump pump to end of the line and add clean gravel to maintain the 1/8 inch slope per foot. You can also add clean outs at this point. I would put them at the corners. Just splice them in and measure correctly for height to the top of the trench.
21. With all pipe in place cover with clean gravel up to at least 3 inches below the floor line. If your basement floor is thicker than 3 inches match the thickness of your existing floor. Just ensure there is at least 3 inches of clean gravel above the drain pipe. This left over space is for the concrete.
22. Now soak all gravel with a ton of water. This will be a good test for your sump to make sure it all flows back to the basin as well as helping compact all the rock together. Also tamp the rocks down. Stomp and jump on them and all that stuff until they are completely compacted down. You dont want any settling to occur after you pour concrete.
23. If you have hollow basement walls or walls that weep at the joint between where the wall sits on the footer you will need to drill relief holes in the wall. For example if you have a cinder block wall you will need to drill a half inch hole in each block cavity to allow the water to drain.
24. Decision time: you can either then insert a small tube in each wall hole and caulk it in place so that it can drain into the clean gravel(make sure the end of the tube goes at least 2 inches into the clean gravel) or you can take dimpled foundation wall wrap and secure it to the wall above the holes. Then fold it into an L shape so it covers the holes and the entire drain line path.  This will allow the water to come through the wall and ride the wrap down to the gravel. It also will stop the concrete from leaking into your clean gravel and possibly your drain pipe (if you mix it too runny). I went with the foundation wrap and secured it using concrete anchors.
25. Seal the top of the foundation wrap with caulk. This will complete the water barrier and not allow water vapor to rise up and into your basement.
26. Now clean your basement floor get all dirt and dust up so you have a clean floor and clean existing concrete for the new concrete to bond to.
27. Calculate the amount of concrete needed and pour concrete in all spaces and level with existing floor. This is the part where you need all your friends. I had 4 yards of concrete to get downstairs into my basement. There was no other option than to bucket it by hand because all of my egress windows were too small and all the local concrete pump companies wanted $5000 to show up for the day. I ordered 4 yards from a local ready mix company and had them mix it on the dry side so set up time was fast but it would not be too runny and lose its shape while working with it. It is best to do this all at once or you will have cold seems all over your floor that could lead to additional water leak points. Also if you have to form concrete over the top of the foundation wrap on the wall. My blocks began above my floor so if I didn't concrete this it would have been exposed and more prone to breaking the caulk seal and leaking.
28. Ur done! The pain and worrying are over. Your basement should now be able to take on copious amounts of ground water.
29. Probably throw a party or something to thank your friends/family.

Project Stats:
Total basement size for reference: 1,000 sq ft
Midwest Basements quoted price $15,500 (included 3 total sump pumps)
My total cost: $2,345
Savings of $13,155!!!!!!!!!!!


Cost breakdown:
Sump Basin: ($50)
Sump Pump:($200)
Battery Back Up Sump: ($200)
Check valve:($25)
Gravel: ($450)
Concrete: ($700)
Jack Hammer Rental: ($300)
Drain pipe:($100)
Foundation Wrap:($150)
Caulk: ($50)
New basement window: ($80)
Concrete saw blades: ($20)
Sledge hammer: ($20)
Concrete tools, anchors, buckets, and shovels: ($0) already owned them
All My Friend Favors: (Priceless)


Post any questions. I'm sure people will have improvements and every situation is different so people will have to make some tweaks here and there but this is a good place to start.

Car Jack

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Re: interior french drain
« Reply #17 on: February 12, 2020, 01:15:44 PM »
First, you need to do your detective work, find the problem and then figure out options as solutions.  Your problem seems exceedingly simple compared to my house.  If I understand right, water comes down a hill, pools and makes its way into the basement.  I would think the solution would be to create a trench of sorts with perf pipe covered in landscape cloth.  Grade so water from the hill and water from the house all make their way to that pipe.  Cover the pipe with crushed stone.  If this is your only problem, you're done.  Have a professional do the grading.

Let me tell you about my wonderful house, what we've done and how it's fared.

Our house was built on a piece of land a bit over 13 acres.  There are at least a dozen test holes where the builder attempted to find a place where the ground would perc.  He couldn't find one.  So he blasted the granite into a nice big granite cup, put in enough crushed stone to get the inspector to pass perc and built the house on top of it. 

So there's problem one.  If water gets under ground, it fills up this giant granite cup and pushes its way through our floor through micro cracks.  Not a lot needs to come up, but high pressure water will continue to drip in until there's 2 inches, then 4 inches of water in the basement.

But there's more!  The house was built without proper grading.  So the entire south facing side of the house routes rain water along the house, gently down a hill, along a sidewalk, around to a basement walk in and into the basement.  I'm not kidding, if I wanted to capture water, that's how I'd do it.

And let's look at where the house is.  We're right next to a hill.  You remember that blasting?  Well, it's blasted into the hill a bit so there's some normal dirt and ground behind the house, but above that is granite ledge and more hill going up.  So when it rains, water comes.......wait for it......down the hill.  What a concept.  Where does it land?  Right at our foundation.  Nice stopping point to soak in and get into that granite cup.

On top of that (and you thought I was done?), the north side of the house is a traditional New England Cape.  That means that the drip edge is less than an inch beyond the exterior wall.  At the base, we have 3 window wells.  (Oh, that sounds cozy).  Well, guess where water goes when it rains?  Down the roof, right?  And over the drip edge with some portion dripping into the window wells.  You'd probably think "he's going to talk about that water getting into the granite cup again, I bet".  Well.....NO!  Because when it really rains, that water actually builds up and fills the window wells.  Then it directly leaks through the edges of the windows directly into the basement.  So a very heavy, short storm is enough to fill the well, drip in and all of a sudden, a quarter of the basement has water all over the floor.

How did we fix all of this mess?  You might think that we took the leftover dynomite from blasting out the hole and blew the thing up.  Nope.  Although that would have been easier.

First, I built a small diversion gully of sorts that starts on the hill behind the house, making its way down the hill to the north side of the house, moving away and then out to the driveway, well downhill.  This does a decent job of diverting surface water from the hill.

For the south side of the house, we had gutters put on that pull all the water to the back of the house, exiting into that gully created above.  Some water still comes down part of the roof so we added another gutter on a porch roof on that side that drains to the sidewalk where I can add a plastic pipe to really divert it.  We also put in a real sidewalk with pavers and diverted some of the water into the lawn.

For the north side of the house, we did a number of things.  We did try gutters but the gutter people all seemed to be clowns and either a downpour or snow would destroy the gutters.  Sigh.  I also put those plastic domed covers over the window wells and that helped a LOT.

Now for the money.

Because water under the basement in that granite cup really could never be completely overcome because every spring, all the snow was going to melt and hold moisture and come under the house, we put in an interior, under slab diversion system with sump pump.  Some things that absolutely differ here from the above recommendation.  So the basement floor was jack hammered about 6 inches to the wall.  Plastic channeling was installed with perferations at the top part to capture water.  Not at the bottom half because we want the water to flow to the sump basin.  This is all, of course angled so the water flows.  Part of the system goes past our walk in door and in case we do get water built up outside that door, there's a garage grate there so it'll go right into the channel.  All that feeds the sump basin with sump pump.  The pump feeds a pipe that goes outside, under the porch, under the lawn, under the driveway and exits on the other side of the driveway, well downhill from the house.  In the spring, when water gets under the house, the sump pump will run for minutes at a time, wait 5 minutes and run again minutes at a time.  So there is still a lot of water under there.  It's been in place now for about 5 years and has never been touched and has always worked fine.  I have a couple submersible pumps from the before time so if there were a failure, I could throw one in while I go to the hardware store, Lowes or Home Depot to pick up a new pump (they're standard and inexpensive).  One key difference here from above.  There are no holes in the basin.  In our case, holes would not make sense.  When things go bad, that would introduce a lot of water into the basin directly.  So long as the water is below the channels, it's below the floor, so it can stay there.  To go lower could potentially mean we're moving the water table.  That isn't reasonable.

There's one more thing we just did.  We needed our roof replaced, so as part of the job, I asked that the north side of the house (cape with 1" of overhang) get a 1 foot extension of the roof and gutters properly installed.  That was done in the fall.

We have not had water in the basement from under the floor since the sump system was installed.  The water from the window wells hasn't been more than a small streak since putting in place the bubbles.  We're into the winter and have had thaws and no water of any kind has been seen on any walls or anywhere on the floor.

Oh....and by the way.  Our old roof had several spots where we had leaks and streaks.  None so far. 

Goldielocks

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Re: interior french drain
« Reply #18 on: February 15, 2020, 01:05:36 AM »
I help manage a old property.   It has a forested hill at the back... a hill that many other properties around it have "natural artesian wells" I think they call it.  Heck, the city has one on the other side that they test for quality and allow people to fill jugs directly from it.

So, water definitely comes off the hill, and more now that the surrounding properties above it are being developed form small houses to mega houses with fewer trees.

The "diversion gully" is our answer this year to what I call "the river".  My problem is that the river runs over a paved parking area and creates an extreme hilly ice hazard when it freezes (because the water keeps coming). 

We also have a sump in the basement of one building.  The building is nearly 150 years old, so this basement is already just dirt, so we dug it out and put in a sump... no french drain because the water just comes from the ground anyway, and the sump is on the hill side.

Go read that long post above about how to install sumps... because...  5 years later, we are putting in a SECOND sump into the same pit.  It turns out that sump pumps don't work when the power goes out, which happens a lot in big heavy storms with lots of rain.   We had to put in a BATTERY BACKUP SUMP.   Those things are not cheap.

Absolute #1 is to divert water away from your home, slope the yard (the surface water from our hill is diverted away about 10 ft from the building and it works very well.).

Having a sump inside just sucks because of all the moisture creating mold, and  of course, those POWER OUTAGES.

Case

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Re: interior french drain
« Reply #19 on: February 15, 2020, 12:25:38 PM »
I had some rain in the basement due to recent heavy storms.  Basically out of luck I noticed the water in the unfinished utility closet, but the rest of my basement is finished.  After pulling back carpet, it looks like water leaks in in a couple locations.  It is usually very little water... so little that I never noticed in a year living here (it gets under the carpet at the edge of the wall, but not enough to actually make the carpet wet (no mold)... just enough that you see it dripping in.  However, when we have heavy record breaking rains, it came in a bit more and we contained it with towels (periodically replacing them).  Our house is on a hill, and he backyard goes slightly uphill on one side.  This side develops standing water when it rains.

Our basement is fully finished, and it's important for re-sale that we keep it nice and protected from the water.
There are a few options:
1.  Do nothing, until we get rains heavy enough that actual water damage occurs, if it ever does.
2.  Have a shallow french drain installed in the backyard to redirect surface water.
3.  Have one of those interior french drain systems installed (e.g. dig up the concrete around the perimeter of the floor, add install drain pipe, weep holes in the concrete block foundation, seal, refinish).

Option 1 is probably a no go unless the upcoming Noreaster causes no water in the basement.  This seems unlikely, as I'd rather have peace of mind even if it costs some thousands of dollars.

Option 2 is a maybe, but basically, I try it out, and if it works great, but there is a chance it wont fix it (e.g. groundwater problem) and then I likely have to go with option 3.

Option 3 was proposed by a contractor, and he proposed we just do it on the sides of the basement with water problems.  I'm not sure of the cost of Option 2, but Option 3 was not too expensive, and Option 3 is guaranteed to fix the problem (both logically and guaranteed by the contractor).  Unless water starts to come in on the other parts of the basement, but it seems unlikely this would happen.  Quote was for $3800 for 64 linear ft of drain, including sump installation.  Price will go up slightly if I get a battery back up pump, which I will.

Any thoughts?  I know that these interior systems are controversial, but an exterior system is an nearly impossible for reasons I wont go into.

For people that have had interior french drains installed, what was your experience?  Any things to watch out for?

Btw, this is not DIY, but I figured the DIY crowd would be more knowledgeable..  i can move the post if inappropriate.

I wanted to say thank you all for the extremely detailed response.  I am not new to basement water problems, and dealt with it in a previous house.  I have spent quite a bit of time thinking about this stuff.

Anyways, what I have realized is that I have not given sufficient detail.  I am working on a follow-up that I think will make issues a little more clear.  The answer seems likely that I need to do some amount of surface french drains to re-route water.  However, in the end, I still have a house that was recently completely renovated but has no perimeter drain about the foundation.  What this means it, is that I will be ok until epic rain events occur.  During these events, who knows?  It seems like an internal system is the only way to prevent the potential destruction of a finished basement.

Case

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Re: interior french drain
« Reply #20 on: February 15, 2020, 02:40:05 PM »
I had some rain in the basement due to recent heavy storms.  Basically out of luck I noticed the water in the unfinished utility closet, but the rest of my basement is finished.  After pulling back carpet, it looks like water leaks in in a couple locations.  It is usually very little water... so little that I never noticed in a year living here (it gets under the carpet at the edge of the wall, but not enough to actually make the carpet wet (no mold)... just enough that you see it dripping in.  However, when we have heavy record breaking rains, it came in a bit more and we contained it with towels (periodically replacing them).  Our house is on a hill, and he backyard goes slightly uphill on one side.  This side develops standing water when it rains.

Our basement is fully finished, and it's important for re-sale that we keep it nice and protected from the water.
There are a few options:
1.  Do nothing, until we get rains heavy enough that actual water damage occurs, if it ever does.
2.  Have a shallow french drain installed in the backyard to redirect surface water.
3.  Have one of those interior french drain systems installed (e.g. dig up the concrete around the perimeter of the floor, add install drain pipe, weep holes in the concrete block foundation, seal, refinish).

Option 1 is probably a no go unless the upcoming Noreaster causes no water in the basement.  This seems unlikely, as I'd rather have peace of mind even if it costs some thousands of dollars.

Option 2 is a maybe, but basically, I try it out, and if it works great, but there is a chance it wont fix it (e.g. groundwater problem) and then I likely have to go with option 3.

Option 3 was proposed by a contractor, and he proposed we just do it on the sides of the basement with water problems.  I'm not sure of the cost of Option 2, but Option 3 was not too expensive, and Option 3 is guaranteed to fix the problem (both logically and guaranteed by the contractor).  Unless water starts to come in on the other parts of the basement, but it seems unlikely this would happen.  Quote was for $3800 for 64 linear ft of drain, including sump installation.  Price will go up slightly if I get a battery back up pump, which I will.

Any thoughts?  I know that these interior systems are controversial, but an exterior system is an nearly impossible for reasons I wont go into.

For people that have had interior french drains installed, what was your experience?  Any things to watch out for?

Btw, this is not DIY, but I figured the DIY crowd would be more knowledgeable..  i can move the post if inappropriate.



Update  2-15-2020:

Here are some images that illustrate my house and hopefully better explain the water situation.  The house is on a hill which slopes significantly down my front lawn.  That same front lawn contains a septic leech field.  This is an important detail as it my be make the ground in the front of my house saturated with water.  In addition to the back-to-front slope of my property, there is a right-to left slope along the street I am on (water slows down street when going right to left, when facing the house). 

My back yard is mostly flat.  However, my neighbor to right of me (when facing house front) is uphill, and the swail between our houses becomes extremely wet due to my neighbor's downspouts, as well as my own downspouts (yellow in picture) and such.  The swail directs water out to the street, but I wonder if this water goes under the garage and down to the basement side. In this location, I am considering installing a shallow french drain to route the water out to the street.

The backyard till become very saturated and with heavy rains, developing standing water.  This occurred especially at the down spout in the middle back of my house, as well as the back of my garage which had clogged gutters at the time (obviously I will never let them clog again).  It is more difficult to imagine how to french drain this water away.  I would tie it into a french drain on the right side.  However, the left side of the house is very narrow, and it would be a little tricky to pipe the water away due to the septic tank system which is in the way (red). 

To the left of my house (when viewed from front) is my other neighbor.  I probably want to avoid dumping water on this side of the property.  Where my property ends there is a 4 foot drop to my neighbors property, and so water would certainly accumulate on his property.

Water came in the basement at two locations (shown in blue).  In both cases it was a gradual leak which was slow enough to be contained with towels.

1.  the front of the basement, directly underneath my patio (which has a roof and slab).  This is where I suspect the leech field may have contributed.  The previous day I ran tub + several faucets for about an hour (long story) which means tons of water went into the leech field.

2.  The back corner of the basement, which is underneath the garage as well as the back patio.  Presumably my clogged gutters contributed here.  Also, the saturated swail on the right side of the house may have contributed.



Things I am considering doing:
1.  Installing surface french drains on the right swail to get rid of the surface water there.
2.  Installing surface french drains in the backyard, but not certain where these will deposit water.
3.  Pulling out the drywall at the problem locations, to better see what is going on at the wall (presumably cracks).
4.  Installing a water barrier in my garden beds to direct water away from my house walls.
5.  Have a contractor install an interior french drain system (under the slab).

Hopefully I don't need to do everything there, as it is some combination of a shit-ton of work, or expensive (how much I hire out). 

I can try the various steps that don't include an interior system, as most here have suggested.  The main issue is that, the only way to know if my efforts will work is to see what happens the next time we have an epic rainfall event.  If the steps dont work, then my basement could get water damage, and it was all for nought.  The interior system at least is an insurance plan, and might be attractive to future buyers when I sell some day.  But, I certainly would not do an interior system only.  I almost certainly am installing a shallow French drain to re-route as much surface water as I can.

If you made it this far, thank you for reading!  Any comments/thoughts are welcome.
a few more images

Goldielocks

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Re: interior french drain
« Reply #21 on: February 16, 2020, 05:08:01 PM »
You need to dig down and (re?) install a perimeter drain on the outside of your foundation.  Yep it costs money, but is the only way, really, if you don't have it already.

Interior perimeter drains are when you do not have the ability to install exterior ones.   Such as you are in a townhouse or a property with minimal clearance outside for digging.

dneck37

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Re: interior french drain
« Reply #22 on: February 17, 2020, 07:59:17 AM »
The detail definitely helps me understand more. I bet if u just take ur downspouts and attach them to an underground pipe running downhill to the end of your front yard it will make a world of difference. Run some on each side of the house connect the downspout on the blue section to whichever run is closer and terminate them at the street so it will flow to storm drains. This should eliminate the standing water which is most likely related to the seepage ur seeing when it rains.

Case

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Re: interior french drain
« Reply #23 on: February 17, 2020, 05:54:22 PM »
The detail definitely helps me understand more. I bet if u just take ur downspouts and attach them to an underground pipe running downhill to the end of your front yard it will make a world of difference. Run some on each side of the house connect the downspout on the blue section to whichever run is closer and terminate them at the street so it will flow to storm drains. This should eliminate the standing water which is most likely related to the seepage ur seeing when it rains.

Thank for the ideas! I'll likely try out the shallow french drains out.  I can definitely get one on the right side of my house, but the left is tricky because snaking a pipe our around our septic tank, while maintaining grading, and not discharging the water all over my neighbors yard... may be tricky.
Where I live we don't have storm drains; rather, our street is the side of a hill, which eventually runs to a creek.

If I were to get an internal french perimeter drain, I would definitely hire that one out.  I admire your dedication in installing it yourself.  That is a pretty intense project, and if I attempted it it would likely be the project that never ends.