Basement Waterproofing What Really Works

[BigBolt]

I have a full walk out basement 26'x48' it has never been flooded but was showing signs of dampness when I first moved in. I remember seeing a product used in underground bunkers making them totally waterproof. I ended up covering the walls in the basement with the Sani-Tred system which was used in the underground bunkers I did this 25 years ago. The product has to be installed on bare concrete. If there is paint or other sealers on it the paint or sealers must be ground off. The basement has been completely dry since I installed the Sani-Tred product. I also replumed the water heater safety valve discharge to the outside. I used a SST flex hose between the water heater and the outside piping. I did this before installing the metal studding, rockwool insulation and 5/8" sheetrock.

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[K22]

Ever consider starting a business?

Mine is so bad that even with an interior French Drain and sump pump, while never flooded, it is like a dungeon it is so damp. While a de-humidifier helps, it's still an unpleasant place.

In 2018 I moved my reloading table upstairs and now reloading is at least tolerable. 

 

[K9TXS]

I don't have a basement, but do have a large crawl space. Several years ago I was doing some work in the crawl space and it was very damp, musty, etc. I had the crawl space encapsulated and they also installed a dehumidifier. I only change a filter in the dehumidifier once a year. No more problems with dampness, water, etc.

Items can actually be stored in the crawl space and remain completely dry and no rust.

 

[BigBolt]

Ever consider starting a business?

Mine is so bad that even with an interior French Drain and sump pump, while never flooded, it is like a dungeon it is so damp. While a de-humidifier helps, it's still an unpleasant place.

In 2018 I moved my reloading table upstairs and now reloading is at least tolerable. 

I had a friend with a 2-foot-thick river rock foundation with dirt floor built around 1800 and always wet in the spring. His basement was 24'x12'. The first thing we did was to lay down 3mil poly and pour a 5000-pound concrete mix in the spring. When summer came everything dries up and we patched any loose mortar. Brushed off the rocks with wire brushes and then applied the water proofing. Where the expansion band around the perimeter meets the walls, we troweled in their rubber sealant before covering the walls. 15 years and no leaks dry as a bone. He finished his basement, and it is his man cave now.

 

[gary0529]

I don't have a basement, but do have a large crawl space. Several years ago I was doing some work in the crawl space and it was very damp, musty, etc. I had the crawl space encapsulated and they also installed a dehumidifier. I only change a filter in the dehumidifier once a year. No more problems with dampness, water, etc.

Items can actually be stored in the crawl space and remain completely dry and no rust.

Before you start, spending big chunks of money with interior, drains and waterproofing systems, make real sure and I mean absolutely sure that your gutters and downspouts are not clogged and there is ample drainage away from your foundation. I had the same problem I interviewed all of the other characters in the business I went with a guy who dug out around the house Applied a rubber sealant to the exterior below grade and then did a really good job draining away all the water off the roof to a natural slope that was nowhere near the house that was 15 years ago and I haven’t had a bit of dampness since that day, just a thought

 

[Rtheurer]

Typically that water proofing is done on the OUTSIDE of the wall and is done Prior to the Foundation walls being backfilled with dirt. The liquid coatings avalable at one time was state of the art and was better than nothing.. Alas.. not perfect. Like all concrete you get small fractures and guess where that water will go? Now they have a Product that is a thick Sheet of pliable rubber that has and Adhesive on one side. Even if the wall cracks the rubber stretches with the crack. This needs to be done prior to back filling with dirt as the Concrete is nice and clean per say. Strip the concrete forms off, put on the water barrier as soon as possible.

Might be something out there that i dont know about... But this should have been done on day one. Sorry...

 

[ebb]

I sealed my fathers with something called Damn-Tight back in the 80s or 90s. but there may be better things now. His was always dry enough to have no problems with dampness.

 

[LHSmith]

When I built I coated the outside foundation with rubberized coating, made provision for a sump pump and perimeter trough and the only thing I had to change was set the pump 2'deeper. I use a dehumidifier spring through fall.
I have to keep the basement liveable, the wife and I live in it as we have a squatter who is also a hoarder living upstairs (MIL-)
It is insulated and finished off and yes because the assessor was nosey I have to pay for the additional 1000 sq. ft.

 

[BigBolt]

There were many products in the 80s and 90s used to waterproof foundations. Today's technology has come a long way since then with far better results. When my house was built in 1990, they used what everyone was using. The sealants eventually will fail as nothing lasts forever. When I was in the USCG our Rate did all kinds of construction from buildings to roads, to piers and heavy construction of just about everything else. Water sheading away from buildings is a must. However, when I was stationed in New Orleans exterior water proofing did not last as there is extreme ground water pressure. We used another sealant like sani-tred on the inside and today 40 years later still dry when others were using sump pumps. So regardless of some old school thoughts newer technology has overtaken those old ways. I worked at a college and a company wanted 60K to dig up around a 30 x 60-foot foundation to waterproof it. we used a company that was a Sani-Tred dealer and installer. They did the whole job for less than half of digging up around the foundation. They did the inside the basement walls an the basement has been dry ever sense.

 

[Dave M.]

When I built I coated the outside foundation with rubberized coating, made provision for a sump pump and perimeter trough and the only thing I had to change was set the pump 2'deeper. I use a dehumidifier spring through fall.
I have to keep the basement liveable, the wife and I live in it as we have a squatter who is also a hoarder living upstairs (MIL-)
It is insulated and finished off and yes because the assessor was nosey I have to pay for the additional 1000 sq. ft.

Throw that squatter out on their ass. Even if you can’t throw them out, you are in the basement and literally control the electrical, water, and possibly even gas to the entire house. Easy fix, turn all the heat / a/c vents off to upstairs, no water upstairs, and zero electrical upstairs. Problem will fix itself really quick. Why are you putting up with a squatter in your house?? I hope for your sake, you are just kidding, but somehow I don’t think that is the case. Good luck. Some people have life too easy and you need to get creative to make them pay.
Dave

 

[Dusty Stevens]

Throw that squatter out on their ass. Even if you can’t throw them out, you are in the basement and literally control the electrical, water, and possibly even gas to the entire house. Easy fix, turn all the heat / a/c vents off to upstairs, no water upstairs, and zero electrical upstairs. Problem will fix itself really quick. Why are you putting up with a squatter in your house?? I hope for your sake, you are just kidding, but somehow I don’t think that is the case. Good luck. Some people have life too easy and you need to get creative to make them pay.
Dave

I think he said it was his mother in law!

 

[DirtySteve]

I think he said it was his mother in law!

What makes you think he did not understand that!!??

 

[Enosiophobia]

Do yourself a favor. Now that you've installed sheetrock, a perfect mold growth product, monitor your humidity levels and consider a dehumidifier.

 

[nakneker]

Waterproof basement = no basement at all. Basements seem to attract problems. I use to build custom homes, did it for 18 years before moving on to commercial construction and I would always advise people to not build a basement. In the area I built homes the soil is expansive, really expansive, it has a high clay content and it’s not a great area to build a basement. When clients insisted then we obliged if their property would accommodate one. I had one sub contractor that I would use, he’s the only one I would use and his basements had a great tract record. The keys to success was drainage, gutters and no short cuts when building and waterproofing the basement walls. We also would pour a 4-5 sidewalk in any area above the basement. if the water can’t drain in a timely matter it’s gonna go somewhere. If the roof sheds water without gutters and drenches your basement area then you’re relying on the water proofing and French drain if you installed one. We only had two basements that leaked, minor leaks and they were a PIA to fix but we did so successfully but my advice has always been build up, not down. If you already have a basement then don't skimp and cut corners. Do it right or hire someone who can.

 

[coldboreshot]

I think he said it was his mother in law!

And the difference being????

 

[thebeav]

I had a thin crack in a basement wall. When it rained hard, I would get a thin stream of water on the floor. Enough to ruin a cardboard box or two, but not life changing.
Believe it or not, about 10 coats of flex-seal stopped the problem.

 

[rwj]

Though convenient, sealing the inside wall surface means that water has penetrated the block/cast concrete and that can be problematic, especially if it freezes!

 

[Gary in MD]

OP
Make sure that that you can still visually check the discharge line from the HW heater. If it starts leaking or blowing, you want to be able to see it so you know there is an issue with the heater. Also put some screen over the end so bugs and such don’t clog it up up and create a problem.

 

[Dusty Stevens]

OP
Make sure that that you can still visually check the discharge line from the HW heater. If it starts leaking or blowing, you want to be able to see it so you know there is an issue with the heater. Also put some screen over the end so bugs and such don’t clog it up up and create a problem.

I always feel of mine when i walk by it so i can tell if its flowing

 

[gunsandgunsmithing]

I agree that the best thing is to keep water away from the wall or sealed from the outside..or both. That said, when I was selling real estate, I saw several basement water issues and had a couple repaired by professional waterproofing companies. I found B-Dry to be the best and they did great work. The system is essentially an indoor french drain. I've seen water shoot upward from cracks in the floor of one.
Their website gives a lot of good info on the whys and what fors related to the underlying causes and how the system works. It's worth a look. Be forwarned though...it's not a cheap system. If I were gonna build with a basement though, I'd consider incorporating it or a similar system into the new build. I haven't looked into that specifically but I'd imagine the cost is much less if done during construction vs after the fact, as a big part of the labor is cutting out concrete about a foot wide around the perimeter of the basement.

Here's a link to them. Interesting reading if nothing else.

French Drains & Waterproofing to Prevent Basement Leaks and Floods – French Drain Help

Expert foundation repair and waterproofing to prevent basement leaks and floods. A B-Dry technician will determine the right repair solution for your foundation from french drains to sump pumps to waterproofing. Our system comes with a life time warranty.

www.b-dry.com