Will a concrete patio area above basement walls stop water?

Question

So, I have a basement that has cracked walls, and there is humidity in the basement.

I got quotes from a few different companies. Quotes were in the area of $10-25K to waterproof the basement.

But I noticed something a day or 2 ago. Not all of my underground basement walls are cracked, broken, and ugly looking. They are relatively in good condition for about half of the wall. I finally figured out why. The good condition section of wall is under a brick porch area that is probably about 30x4ft. The cracked span of wall is covered up only by grass. I really dont want to pay $10K...let alone $25K to take the pain off my walls and lower the humidity.

So, my question is...do you think that extending the concrete porch so that its above the other span of wall....would help and maybe resolve my issue?

I could still do carbon straps on my walls for $8K, just incase they want to bow in the future....but...from everything I can see....this would be the best and cheapest solution. I also though about extending my roof a bit.

BTW, I do know about other solutions such as...fixing the grade, underground waterproofing, interior drains, weep holes, dehumidifiers, etc. Ive done lots of research.

Another solution Ive strongly considered is...installing a french drain some 4ft below grade, and then extending my roof out a bit. I actually think this might be a pretty good solution, but not cheap as just extending the porch area.

Thanks in advance.

Ed O. · Answer

It could help for sure. I wouldn't try it first.

My bet it that it can probably be resolved by addressing rainwater and more effectively getting it away from the house. Placement and maintenance of gutters and downspouts can often be the greatest influence on issues like this. I'd suggest watching the rainwater during a downpour to see obvious issues that you won't observe when it's dry. Nothing can simulate a lot of rain... gotta throw a raincoat on and observe it in progress.

Jon Q. · Answer

As other people mentioned:

(1) all four sides of the house need to be downward sloping (sloping away from the house).

If they're not, fix them... moving dirt is an easy fix.

(2) rain gutters should be clean, be properly installed, and they need to route water away from the house foundation.

(3) if you still have humidity in the basement, install humidity sensing fans that will auto turn on when humidity reaches a specified level (not expensive).

Jon Q. · Answer

Water needs a place to go and that needs to be away from your basement walls.

It needs to be dug outside and basement walls sealed from the outside, then a trench along those walls dug into concrete in your basement with a sump pump installed beneath to pump water out to your back yard or wherever your ground slopes down.  It will be costly, but there's no other way around it that will last for the long term.

Robert Newman · Answer

I'm very interested, were you able to find an effective remedy?

In my experience having had 3 houses with basements, grading, gutter diversion and drainage if needed are a good system of keeping your basement dry. The house I live in now gets a little water in one corner but other than that the humidity is normal for a basement. I don't have that issue. I run 1 Whirlpool humidifier as needed snd it does the job (best value I got online from Costco).

It's very frustrating for sure. And without really excavating or taking soil samples, it's hard to know what you're dealing with until you actually see it or see what the water table is like underground. A concrete pad or extending your patio may indeed help. However that is a major step to take and then you have more concrete to deal with if it does not solve the problem.

Speaking of hard to tell what you're dealing with till you look into it more, There could be a pipe or something going on underground that you don't even know about that past owners did that could be contributing to the problem. They may have tried to fix it and made it worse and you just never know with an old house.

The house I live in now they had run the gutter downspouts into a French drain along the edge of the house years ago. That was part of my water problem right there that old pipe. you should never run a French drain and a gutter down spout as the same pipe. And you want your gutter water to go away from the house. Not right along the foundation! That was a major fail from probably initial construction.

Mike Smith · Answer

@Eron A. Don't wait for rain and try to time getting over there to see where it runs.  Simply put a yard sprinkler up on your roof and let it run for a while.  Watch where the water goes.  Most basement moisture issues can be solved with:

1.  Grading - you must have 6" in fall away for the house in the first 10' for all soil areas.  Concrete must be sloped a minimum of 1/4" per 1', or 2.5" in 10'.  Pavers can be sloped in between concrete and soil.

2.  Gutters - make sure the house is fully guttered.

3.  Downspout extensions - make sure the downspouts extend at least 5' away for the house (and see item #1).

If you don't solve the grading issue, you must turn your basement walls into a waterproof dam that is 8-10 deep.  Good luck with that...

Scott Mac · Answer

Hi Eron,

Well you could test it out by laying a big plastic sheet over the area and seeing if it works.

But if the water is coming from a general raising of ground water that won't stop it.

Good Luck!

Eron A. · Answer

been trying hard to avoid excavating. and remember now......there is a span of wall that is nice and clear...and not too cracked up. so whether or not they waterproofed or not........that span of concrete blocks are relatively undamaged. it doesnt make sense that they would waterproof that span, and not the other span.

so this is why i think i can just cover the damaged span of concrete blocks with a porch or something so that water wouldnt get to the span of exterior wall. id actually probably use plastic tarp in the beginning, so i could uncover that area during days of sun in hopes that any moisture inside the dirt would evaporate. when it rains, id cover up that area again with a huge plastic tarp.

i would also improve the grading, and well the downspouts are already good.

i could also do a french drain type thing...but i dont think that would be necessary.

im really trying to avoid excavating. i dont want to pay $25K lool. i already have mold issues on interior joists that will need to be blasted off...and these joists are 30ft long and there are probably 50 of them going across the basement. and yesterday i was looking at some studs...and i think i mightve seen some mold on those too. super annoying, man.

Russell W. · Answer

So you have concrete block walls, not concrete walls. Big difference. Concrete block walls are extremely porous. Not at all surprised you have high humidity; the hydrostatic pressure is forcing moisture through the pours of the block, past the interior cell (even if not fully grouted) and out the pours of the interior face. Hard to tell from the pictures but I think the variation in color we're seeing in #2, 3, 4 is the moisture? If this had been built correctly, then the exterior face of the blocks would have been coated with a fluid applied waterproofing to seal the blocks. Seems like this may not have been the case, but you can't know without some excavating. This can be accomplished from the interior as well, however it's more effective preventing moisture from coming in (exterior), rather than holding moisture back (interior).

Will a concrete patio area above basement walls stop water?

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