Interior basement waterproofing is sort of like that Dutch kid who keeps the water from leaking into the city by sticking his finger in the hole.
You just need to do two things.
1. Find the cracks in your basement where water might seep in.
2. Fill those cracks with something that keeps water out.
Sounds easy enough but the cracks usually aren't gushing with water so they aren't easy to spot. And all basement cracks are not the same each requires a slightly different technique to seal properly.
Do you need to find and fill in these cracks as part of the overall basement waterproofing strategy? Or is this just for people with actually water coming through?
Stay with me through the end of this article and we're going to talk about that. At the very least you should be aware of these 3 potential problems.
Here are the 3 most commons interior basement waterproofing steps you can take to ensure a dry basement now and in the future.
#1 Tie Rod Holes
My exterior article talks about the porous nature of concrete, and how susceptible it is to water diffusion. Even if the concrete is perfect sloppy construction can also create interior basement waterproofing challenges. Allow me to explain.
Most concrete foundation walls were built with reinforced tie rods. These rods hold the forms together while your basement walls were poured. 
Once the forms are removed, the rods are sticking out of your brand new wall. So the low man on the totem pole walks around with a hammer, and knocks the ends off.
On top of not being the most aesthetic looking thing tie-rod holes are a potential water entry hole.
An exterior waterproofing member is supposed to be applied after the forms are removed, but this can breakdown over time allowing water to weep through.
You can proactively prevent future leaks through tie-rod holes using hydraulic cement.
Hydraulic Cement Application
Hydraulic cement hardens fast! They warn you on the bucket, and I'm warning you now. That's 2 warnings - don't say I didn't tell ya so.
Its a simple job to do. The trick is just be prepared. Have all of your tools laid out. Make sure you have several buckets for clean water, dirty water and mixing on standby. Don't mix up more than you can apply in under 5 minutes.
The first batch I mixed to the "pudding" consistency they recommend. So I got some on my trowel, applied it to the wall and looked back down to notice my cement was almost already hard?!? I'm telling you - stick and move on this one.
Once the cement becomes too hard to apply, use your water buckets to mix up another batch. Rinse and repeat until all your tie rod holes are sealed shut!
#2 Basement Floor and Wall Cracks
Some people really freak out when they see cracks in their basement. Relax Frankie, most basement cracks are very normal and will not threaten the structural integrity of your home.
These cracks can be convenient locations for water to enter. With a few bucks and an hours worth of time - you can fill these cracks as part of your interior basement waterproofing plan.
For cracks in the floor and where the floor meets the wall, I recommend applying concrete repair. Most home improvement stores sell cement repair in tubed form for simple application with a standard caulk gun. 
Get yourself a tube, make sure your crack is swept, vacuumed, and dry, and pump it in. You can smooth excess out, but I didn't bother with aesthetics since I was planning to cover all cracks with dry wall, carpeting, etc.
Point here is to make sure you prevent water entry, not necessarily make it pretty. If you are applying to an area you aren't going to be covering, you'll obviously care more about that then I did.
It's a bit more expensive but polyurethane will work better and last longer than an acrylic or silicone based filler. If your goal is to never deal with these cracks again - pick up a tube of DAP Polyurethane 18814 at Amazon.
#3 Beam Pockets
Another water entry "hot spot" are beam pockets. Sounds like something you get when you buy a fancy pair of jeans. (not that I have fancy jeans, I'm justing saying...) Actually this is where your support beams meet your foundation wall.
There are do-it-yourself methods to sealing these but mine was leaking good so I called in the professionals. A company came out and explained this is a common area for leakage.
To fix it they had to do two things. First they drilled through the concrete (which I wasn't comfortable doing on my own). Then they used special plugs and equipment to inject polyurethane resin. The resin seeps deeps into the cracks sealing the inside and the outside.
Most companies fully guarantee their work, and while it was a little costly (around $500), to me, it was worth the piece of mind.
What interior basement waterproofing do you need to do?
If you have obvious cracks in your basement floor or walls I would suggest that it's worth the money and time to fill those before you start finishing your basement. It won't take long or cost a lot and you'll have piece of mind for the future even if you aren't currently seeing any signs of water coming in.
As for the beam pockets. If you don't have an obvious water issue with your beam pockets I would not spend the extra time or money to seal them.
Hope you are another step closer on your road to a dryer basement. Have you done your own beam pocket repair? How'd it turn out?
Is there anything about interior basement waterproofing that I'm missing?
Leave me a note in the comments section below!
- Adam
More dry, good smelling links:
- Here's our article on exterior basement waterproofing.
- What about basement waterproofing paint? We've got you covered.
- Check out US basement waterproofing website, lots of great articles and videos.
One thing we recommend and implement with our basements is using drain tiles and some sort of sub pump system outside. Here in Chicago we have major problems when we get a heavy rainfall. However the solutions you have provided will do the trick for most basements.
I HAVE BEEN IN THIS HOUSE FOR 37 YRS. ABOUT 10 YRS AGO A BASEMENT WALL DEVELOPED LEAKS AT 2 CRACKS ON THE SAME WALL, WITHIN 15 FEET OF EACH OTHER. IT IS NOT POSSIBLE TO ACCESS FROM THE OUTSIDE BECAUUSE OF AN 18' X 36' DECK WITH TILE COVERED COUNTER WITH SINK ETC. EXTREMELY C OSTLY TO REMOVE & REPLACE. THEREFORE REPAIR MUST BE DONE FROM INSIDE. CAN YOU RECOMEND A COMPANY, ON LONG ISLAND, NY, WHICH WOULD DO THE POYURETHANE RESIN INJECTION YOU SUGGEST? DO YOU HAVE ANY OTHER DIY SUGGESTIONS? THANK YOU.
Peter - Sorry to hear that! Being from Chicago area myself, I wouldn't be able to recommend anyone particular in New York. I used U.S. Waterproofing and they did a great job, although I perceived it to be a little costly. See if they have a New York branch! Good luck!
Would you use self-leveling compound to level the floor before framing? I haven't seen this mentioned.
About those rod holes... I'm getting conflicting info. On the website it says that the tie rod ends are hammered off. That would mean the tie rod is still in there, only there's a small hole in front of it that needs to be filled. In my basement, I found a cork, and nothing behind it. There's at lease 5 inches of empty hole, doesn't look like the rod hole is even there. Are they actually all pulled out completely and then plugged with a cork?
I have some cracks in my basement that I have been working on filling in. You are right that it is easy to fill them and I really like your suggestion of using a caulk gun. However, I can't help thinking that the best way to waterproof my basement is to make sure the water has somewhere else to go. AKA I need good drainage. Do you have any recommendations about how to make sure there is proper drainage around my house?
What up James. Yes, read this post - https://ifinishedmybasement.com/getting-started/gutters-downspouts/. Jason
Hi Jason, Nice website to use for reference.
You have written about water-proofing the walls and filling the cracks in the floor. You haven't mentioned anything about doing any moisture barrier or moisture block to the floor. I would appreciate your opinion on it.
Thank you, Kumar
Hi Jason, this is great information, thank you for sharing. I am starting a basement project. and althoug my basemnt looks and feels very dry, i noticed the concrete walls have these metal tabs that served as spacers when the walls were poured. I read some where that these tabs had to come out because they will eventually rott and water will leek into basement.
My basement has flooded multiple times. We have a mixture of the rod holes and cracks that you talked about. I'm going to take your advice and try to waterproof the concrete. Do you think it's a good idea to have it done professionally?
The method he outlined will work if done well. But it will also fail...someday.
It might take 20yrs. It might take 2. A professional company should be in the ballpark of $20/rod hole and $450/crack. Make sure it is a high pressure injection. The salesman won't know the PSI, so you'll throw him off if you ask. Make sure the company is using at least 2500PSI minimum.
Hi Jason
I have concrete foundation (50 years old Toronto house).Water seeps when it rains continously into my basement. I called couple of contractors and some said exterior waterproofing some said interior drainage system.
I'm confused what to go with. They are charging almost the same for 15 feet area.
This is just my opinion, every house is differently, but I prefer to "remove the water" rather than try to block it from coming in. So my vote would be for proper drainage. - Jason
I have a waste pipe from the toilet on the floor above that comes through the basement wall on the floor below. This is a multi level house. When the plumber originally made the hole he used a hammer drill and just knocked out about an 8" round hole and never sealed it up. Now when the ground becomes very saturated I get water that will leak down the wall until the water table goes back down. It is extremely frustrating. The plumber came back and tried using concrete to patch the hole. This did not work because I believe it is to porous and leaked through that. I have started the repair myself by using a polyurethane expanding foam. Just wondering what I should do to finish it off. I was thinking hydraulic cement possibly because I would like it to blend in with the rest of the wall. Any suggestions are greatly appreciated.
Have a professional look at it. Is there a floor drain nearby that you could use to divert the leak? Stopping that water from the inside is like trying to patch a tire from the outside. It's backwards. Ideally you could get under the floor on the higher level to stop the water from that side, but I'm guessing that isn't an option?
Does DAP 18814, which you recommended for cracks in the floor, also work for cracks in the wall and rod holes as well? Or is it too liquid? I am seeing these compressed swell plugs from TRX advertised online. They look easy, but at $5 each they are considerably more expensive than using hydraulic cement. How permanent a solution are they?
As the inventor of the TRX Compressed Swell Plug, I can attest that it works from 20 years of in-field application.
As a waterproofing professional with over 30yrs experience, I always tell people that if they can't afford to have a professional treat the rod holes correctly, then the hydraulic cement method you outlined is their best "stop gap" to hold them over. "Negative side" (inside) waterproofing is what your outlining as opposed to "positive side" (outside)where you would be using tar or mastic on the outside. The polyurethane injection technique is a great option for lasting results and should cost around $20/Rod hole or $450/crack from a reputable company. Technically the urethane injection technique is a positive side waterproofing method since the urethane actually fills the entire crack or rod hole from the inside and mushrooms out of the wall on the outside preventing water from ever getting into the wall in the first place. The hydraulic cement method will break down over time and be rendered ineffective just as the original "patch" that was installed when the home was built broke down. When the hydraulic cement fails it will lead to a costly repair if someone has finished their basement. My advice would be if you can't afford to have a professional waterproof your basement then you can't afford to finish it properly.
Just got started and already discouraged. Although I've barely ever seen significant water in the basement in my 6 years of ownership (except a tiny stream that was caused by a now-fixed ripping hose bib), upon tearing back the old wood paneling I am seeing a lot of evidence of moisture/water both at the base of the wood paneling and on the horizontal wood strapping (3, 5 and 7 ft high) the paneling is nailed to. The walls are cinder block. In addition to that I have cracks and signs of what appears to be just general seepage (efflorescence) all over the walls. Also, mortar in need of repair and paint badly peeling. Other than that things are going great. Call the pros?
I'm afraid so. You gotta nail this water issue before you move forward. I really need a whole separate website dealing with moisture so people can solve it themselves but... I don't have that right now. If it were me, I'd call a waterproofing pro. - Jason
Hi, starting to finish my basement. One big question I have is that my basement has two doorways. How and what product should I use to seal or fill in the space that's between the door frame and concrete foundation?
My basement has been showing leaking on the interior, and I have beams in particular that look like they've been having some water come through them. I'm in the same boat as you in that I definitely don't feel comfortable drilling through the concrete myself, so I'll probably end up hiring a professional to do it. It's nice to know that the resin will be able to seal the cracks both inside and outside, and I agree that it's definitely worth the peace of mind to have it done.
Our house in Northern Utah is less than a year old, but we did not purchase it from the builder. I have 2 concerns regarding waterproofing. 1, as new as this house is I am worried that over the next several years new cracks will form causing an issue down the road. 2, the concrete walls all have blanket fiberglass insulation nailed (that’s right, nailed) to them so I can’t see if there are any issues to address. No water in the basement yet. Should I take the blankets down? When can I be confident new cracks will not show up?
Hey Robbie - Nailing insulation with a powder actuated gun is pretty common (typically its only nailed on the top 4' of the wall). Regardless, you may see some hairline cracks appear over the next few years but if you don't see water then the exterior waterproofing is doing its job. Monolithic concrete walls are very reliable.
- Jason
Greetings! Due to a heavy rain last night, my second cousin just found out that his basement has been partially flooded. You did a great job in letting us know that sealing every single beam pocket in our basement could be just what we need in order to keep the space dry. I believe it would be smart if he employs some experts to resolve the issue pretty soon.