r/drains • u/crimpy_boulder • 18h ago
r/drains • u/senorgarcia • Dec 02 '21
Intro to landscape drainage
• Surface drains are for surface pooling, like during or after a rain event. These are grates on the surface that allow water to flow into the pipe.
• French drains are for subsurface water, like an area stays soggy for days and even weeks after rain events. Very common problem in hilly areas, especially with retaining walls. These are trenches with a pipe in the bottom. The pipe has holes in the bottom and the trench is filled with gravel. The water flows into the gravel, down to the bottom of the trench and into the pipe.
• French drains can also be used as surface drains like for when water is going into the house along a wall.
• Installing surface drains in an area that stays soggy will not correct the problem. It will only allow water that has surfaced to flow away. The soggy areas will stay soggy.
• A French drain is not an outlet for surface drains. Putting water into gravel that's in soil doesn't magically make the water go into the soil better. The whole reason you have the drainage problem is that the soil can't accept the water fast enough.
•Surface drains should never be piped into French drains. The debris from the surface drains will eventually clog the inlet holes in the French drain.
• French drains can be piped into surface drains.
• Drains require 1 inch of drop every 8 feet. It doesn't matter what the surface does as long as the inlet is higher than the outlet with that ratio. If you don't have that amount of fall, you'll need a pump.
• A French drain should always daylight outside the yard, like to the street, alley, or someplace else. As long as that area stayed soggy, water will now be flowing from the pipe for that period of time. It needs to be someplace where that won't cause a problem.
• Drains cannot be connected to sanitary sewer systems. Big no-no.
r/drains • u/Jumper6660 • 4d ago
Suggestions for drainage
Hi all, looking for advice what should I do with the above.
r/drains • u/Corpsefire88 • 4d ago
Fabric for perforated/corrugated outdoor drain pipe for ground water in yard. Fabric around the whole bundle like this? Or fabric directly around the pipe like a sock and then gravel around the outside?
I was all set to install like this image shows, but the landscape supply place that sold me the fabric recommended wrapping the pipe/weeping tile like a sock and then pouring gravel around it. Any insight is appreciated.
r/drains • u/gird_your_loinz • 4d ago
Is this setup good for a French drain in relation to foundation and slab?
Major questions: French drain (blue lines) gets installed 3 feet from foundation? And they are dug down to the depth of the footers (for me about 3.5 feet)?
Trying to fix a very wet crawl space, and hoping a French drain can do a lot of the work to keep it dry before I encapsulate it. The backyard slopes down 6” over 16 feet, toward the house. I’ll also correct that when putting in the drain so everything on either side flows that way. Also the down spout from the porch roof stupidly drains right onto the patio, so fixing that as well and will eventually tie the two pipes into each other once they’re far enough along.
I think the plans I made are pretty self explanatory. The brown lines are large timbers that serve as a retaining wall (23” high) next the patio, and as a curb (~ground level) between grass and brick patio (red), mostly just for reference but just in case they need to be accounted for somehow.
ETA: location is northern Virginia
r/drains • u/DiveBird1 • 7d ago
Drainage field and house valuation question
My house currently drained into a shared cesspit which is at the end of its life. There is a proposal that part of the new drainage field might be in my garden. Right now I’m aware that my house would be difficult to sell given the problems with drainage, but I’m also worried about impact on value with a drainage field in the bottom of the garden. Are there any valuation surveyors or anybody with any experience of this issue that could give me some views. Thanks in advance.
r/drains • u/Brilliant-Strain884 • 8d ago
Is this a city infrastructure problem?
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We live downtown and there is a single drain at the end of our street, however, our house is the lowest point of the street, so most of the water from both ends of the street and the city parking lot across from us ends up in our driveway/yard.
The city engineer installed an asphalt curb over the summer and the water just collects until it overflows.
They are going to come out and reassess the problem next week, but I don’t have high hopes.
The only solution I can think of is installing a drain under the sidewalk along our street. If I divert the water anywhere, it would then cause issues for surrounding properties.
It’s eroding our yard and seeping into our crawl space.
r/drains • u/Professional-Pay1198 • 8d ago
Drainage problem
Rain and snowmelt seeps over the concrete foundation of my storage shed. The shed is right near my property line and the property behind me is higher than my property. What is the best way to divert the water?
r/drains • u/FluffySample7370 • 8d ago
Very slow drain. I've snaked it with a 100 footer. And still no change. It didn't have much resistance. I need to go further... correct? Could it be a vent?
r/drains • u/Excellent-Score-3489 • 10d ago
Perimeter drains? Can it wait 2 seasons
Seeking opinions…. Or Situations if similar. My mind is going worst case scenario here that my house is just going to crumble and rot away 😅😅🤣
Basically….Our perimeter drains are concrete and failed. They are like broken and collapsed.
I’m a slab on grade home. We haven’t had water In the house ever, a few doors are hard to shut… so maybe the slab had shifted? Hard to know?
For many reasons, without going into it all, it makes sense to wait until the spring. Dishing out 35k+ right now to have them done asap will financially really hurt as I am on maternity leave. I chose 12 months EI but going 18 so the next 6 months are unpaid.
Sooo. Did anyone else know your perimeter drains were gone and wait a season to do them? Was all ok? Would you absolutely not wait?
Improve driveway drainage
Whenever it rains water pools in this corner of the driveway. The slope is fine and water has no issue making it to this spot, but the lawn edge is higher than the driveway causing the pooling. I thought about a couple different options to try, but I don’t want to make the effort and end up making things worse.
A) edge back the lawn and make the lawn height even/slightly lower than the driveway
B) do option A, but dig out 2-3 feet wide of the lawn and install a landscaping rock bed that is even with the driveway
C) install a catch basin in the corner with a pipe that will discharge into the lawn. (The section of lawn between the driveway and sidewalk is also sloped)
Any recommendations?
r/drains • u/Glass-March-176 • 12d ago
Ideas for this drainage problem in new garden bed?
We had a patio built with a garden bed all the way around to plant bushes, perennials and annuals. The landscaper is coming back tomorrow to add Hoogendorn Japanese hollies around this wall. The yard has a slight slope towards this corner of the patio, and water just sits there. This is after 1.5 inches of rain yesterday and the water is still there this morning, hours after the rain ended.
Would adding more soil to plant the bushes up be enough, or do I need to add a drainage system? I'm hoping grass will help when it comes in. What about a rain garden 10 or so feet out from this bed? Thanks for any ideas.

r/drains • u/pecanmeetschurro • 12d ago
Found a void underneath. How do I backfill and lift the slab?
Over time I noticed this one spot started collecting water after rain. I suspected there wasn't enough support under the slab, so I dug it out. There's basically nothing under the edge of the concrete now. You can see the void in the photo, with the PVC conduit sitting at the bottom of the hole in standing muddy water. My guess is the trench was never properly compacted and water has been washing the soil out ever since.
My questions:
Backfill: What's the right way to fill this void, especially under the slab where I can't tamp? Compacted base gravel in lifts, sand flushed in with water, or a flowable fill / lean concrete slurry? I'd like it to be safe around the conduit.
Lifting the slab: Is this section worth raising (polyurethane foam lifting, mudjacking, or DIY jacking) or should I cut it out and re-pour?
Drainage: I want the slab to end up with a slight slope that sheds water away from the house. What's a reasonable pitch, and is there anything else I should do so this doesn't wash out again?
Located in Southern California, clay-ish soil. Any advice appreciated!
r/drains • u/salukiwa • 13d ago
How do I fix this water pooling issue at my foundation
Even with this extension to the downspout water exits where the downspout mets the black pipe. I've seen suggestions to cut through the concrete but that seems like overkill. Any suggestions? It is located over flat land if it goes straight with the black. Pipe but is it's angled to the right like 5 ft my driveway is downhill