So where does water come from?
"Well Adam, when two hydrogen atoms and an oxygen atom really love each other...."
Come on, you know what I meant! 
How does it get into your BASEMENT?
At its simplest, it’s either coming from inside or outside. If water is coming from outside (the usual culprit), I recommend reading on for some tips and tricks on exterior basement waterproofing.
If it’s coming from inside, I recommend calling a good plumber. Perhaps the Mario Bros are available? Or are they out of the plumbing game now that they have princesses to save and go-karts to race?
Exterior Basement Waterproofing: Gutters/Downspouts -
Gutters and downspouts are an essential component to your overall basement waterproofing plan.
Make sure gutters are clean: The frequency you need to clean them varies directly with the maturity of foliage around your house.
At our starter home, we had two, 100+ year old maple trees towering directly over our house. I would need to get up there at least twice a year to perform a HEAVY cleaning.
By comparison, our current home is in a newer subdivision. No tree on the block even approaches our roof line. Regardless, get up there at least once a year to give them a quick clean out ensuring all gunk is clear including loose asphalt sediment that erodes from your shingles.
If you have a power washer, bust it out and make quick work of it, otherwise a ladder and garden shovel should do the trick. Always remember proper safety techniques on ladders. A good reference can be found here
Make sure gutters are properly pitched: If your gutters are clogged or pitched improperly, water will accumulate or flow away from down spouts causing it to fall over the edges instead of where you want it to go.
If it’s falling over the edge of your gutters, you might as well not even have gutters. Water will continue to fall at the base of your house, near your foundation, which is exactly where the gutters are trying to divert it away from. This water will eventually find its way into your basement instead of the sewer.
If you suspect your gutters are improperly pitched or inadequately sized for your roof, head out during your next heavy rain and take note of your gutters performance.
Alternatively, get up there with your garden hose and spray away; if there is substantial accumulation with a hose, it’s likely not keeping up with moderate rain either.
Down spouts & Down spout extensions: Now that your gutters are performing well, don't get sloppy on the down spouts. There is not much to down spouts, but every down spout should have an extension.
I've seen them done many ways. Pieces of extra down spout, flexible tubing (usually comes in brown or green), or automatic versions which rollout during rain and retract otherwise are most common.
Personally I use the flexible tubing version for my home, but the key is to make sure its dispensing water 4-6 feet from the house and away from your foundation.
Landscape Grading
The pitch of everything surrounding your house is another key component to successful exterior basement waterproofing.
Dirt/Mulch/Grass: Seems simple enough, and it is. People just don’t think to look at it or fix it. The trick here is to just make sure the grading around your foundation is tapered away from your house.
As you add new mulch annually make sure you add more towards your house and less away from it creating a gently slope to carry away water. It doesn't need to be dramatic, just enough to let the water flow naturally.
Concrete/Asphalt: Over time, concrete and asphalt will tend to settle and usually in the wrong direction. This creates a pitch towards your foundation.
There are options (some more expensive than others) to fix this. Asphalt is usually easier to repair compared to concrete. If concrete is an issue, you may want to explore mud-jacking. I have no first hand experience with that process, but it’s one way to avoid completely replacing sunken concrete.
Hope these exterior basement waterproofing tips helped you on your way to a drier basement.
Questions? Have you had mudjacking done before? Let me know how it worked in the comments section below!
- Adam
during big rains I can get as much as 2" of water in our basement. The walls are tight and dry but the floor is the problem. Paint?? or something I can get from the big box stores??
Uuuhhhh Craig... paint won't solve this one. The water is coming from underneath your floor. You can either prevent it from going underneath your floor or you can pump it out. I would start with prevention. Try adding downspouts and gutters that drain at least 6 feet from your house. Check your grading around your house, make sure water can't find it's way to your basement. After that, if you're still getting water - you may want to consider a sump pump. - Jason
Knock on wood I have zero water issues in my basement. That being said do I have to put Ina vapor barrier for the exterior walls? There was vapor barrier put into the concrete slab and then an external water proofer was put ont he external walls before they back filled. Thanks.
Yo Jeff - Well... As much as I love redundancy in my processes and systems; in this case I think you got it covered (already). If it's my money and time, I'm not adding the extra barrier. - Jason
Can the hydrostatic pressure of the water table under your basement floor push water into the basement through the cove?
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Had water entering basement during heavy rain. traced leak to electrical conduit leaking around hole in foundation. Sealed around conduit piping on exterior of foundation.
My crawl space has foundation walls that are really wet on one side. Outside of the wall that is wet is the gutter. The water was running through the walls because there wasn't proper run-off under the gutter. We have put a flex. tube at the end of the gutter now. What will happen to this wall over time? Will it dry out and not be a problem anymore?
The concrete will dry out overtime if the soil or backfill on the exterior dries out. If you live in a climate where you will get frozen ground, then you really want to dealwith grading away from the house come springtime and maybe snow blow the snow away from your house in the meantime. Wet soil that freezes expands,and overtime can push your wall in.
What product to you recomment to patch a concrete wall where water is coming in. I want to chisel it a bit to make the area a little bigger then patch it. I also want to check outside to see if there is a fault there also.
My area has been experiencing some flooding, which has caused a bit of leaking into my basement, and I want to get it waterproofed for now and next time there's flooding going on. Of course, I make sure that my gutters are kept clean and in good shape with all the rain we get, but I think that getting the concrete and asphalt fixed will be key to solving the issue. I'll have to see if anyone in my area offers mud jacking, as you mentioned, and if not then I may just have to replace the sunken concrete.
Phew! I felt so much better know knowing that we could easily waterproof our house by simply reorganizing the mulch supply around it for better water flow. Since last month, my husband found out that certain areas near our house are filled with small puddles every time it rains. I guess I'll have to hire someone to check on the matter and repair anything necessary later on.