7" Rain this month, Wet basement walls, what is the best sealer product?

Question

Western Washington has had more than it's share of rain this winter. Seven inches this month alone. One of my properties has a full basement with cinder block foundation walls framed out with sheetrock. The lower half of sheetrock in one room was removed to find the source. One wall is saturated and thank goodness without cracks. It is getting aired and ready to be worked on.

What is the best SEALER product you have used?  When the framing and sheetrock were installed all the cinder block was quad coated (four layers) with 'Dry Lock'. It held for 10 years.  What do I use now?  DL over DL?  Do you have any special tips or tricks for this restoration process?

Ben Skove · Answer

Lisa,

Before sealing the inside, you need to be confident that you've redirected water away from the exterior of the foundation. While that much rain can defeat what might ordinarily work, it would be good to review that your downspouts are directing water at least 5-6 feet from your foundation, that the ground is sloping away from your house, and that you have swales or french drains intercepting any water moving down slopes or hills towards the house.

On the other hand, if you're dealing with a high water table, it's a different ballgame.

My experience with Drylok is that it works well with minor amounts of water, but that any significant hydrostatic pressure will defeat it.

Sam Leon · Answer

I think you might want to determine cause of this moisture penetration before devising a cure.

if its high water table it should exhibit similar issues on all sides of your basement.

Is the problem localized to one wall?  What's different there?

Is the house built on a sloping hillside?

Any nearby water feature overflowing or leaking? Koi ponds, swimming pools?

Any chance of a gutter clogged with leaves and rain is overflowing out in a wrong spot?  Check all downspouts.

Sprinkler lines?  A underground bust could contribute to the problem...

Christian Lincoln · Answer

Hydrostatic pressure. just imagine a tube of water you're holding and you put a pin in it at the top, no big deal. Then put a pin in the bottom of the tube. Imagine the pressure of 4' of tube water pushing out that pin hole.  The ground is like this on the ext. of your basement walls.  five or six feet of heavy moist ground and water.

so Drylok is good as is hydraulic/water curing types of cement, but these are band aids.

The expensive fix is french drains around the house.  Big project. If it is water table and the floor of the basement is not a slab I'd put a french drain in the actual basement ground running to a sump pump in the corner. I'd cover it with gravel, and maybe a vapor barrier and then pour a few inches of new slab. This will force away ground moisture to pump bucket and out of the house.

How wet is it?  If it's just wall moisture, no puddles, I'd put in two dehumidifiers and a couple fans.  I'd make sure there was no mold anywhere (different route) and then when it was dry enough, I'd use Drylok Extreme.

Lisa Miller · Answer

Excellent points @Sam Leon

The gutters are an issue in two places. One I noticed yesterday, a rusted out line about 6" long and water was flowing out. This about five feet away from my wall issue but the flowing water lands on cement splashing everywhere. The other is a point where three roofs combine to one gutter and in high rain it's just to much for one gutter to handle. It overflows about a foot or two beyond the combination weighing down the gutter and spilling over the edge.  they should each have their own down spout hooking up to the French drain.  And the other simply needs to be replaced. Great call, as I've been looking down and should have been looking up! Thanks

Lisa Miller · Answer

9.5" of rain for the month of March and the average... 3.5"

Thanks for all your comments it has given me hope. The water is gone as we've had two dry days and a couple more forecasted. I'd have to rip out cement and asphalt to do a curtain drain as there is no dirt on two sides of the house.  No black mold, thank goodness. I'll update as I learn and or discover more.

Bill S. · Answer

Really and truly the exterior French drain is the only real solution. Interior French drains and drain tile systems, while providing relief that is relatively inexpensive, are inferior to the exterior French drain system from a technical perspective. Basic reason being the exterior system is the only one that keeps the outside of the walls dry. The reality is that since all this work was done before, this is a recurring problem and the fixes done to date come up lacking.

Ben Skove · Answer

Christian explained hydrostatic pressure well. If there is waterlogged soil outside the foundation with all of that rain, the pressure increases with depth, and it's pushing its way into the basement through the Drylok.

I agree that if it's just wall moisture and that this is an outlying event (i.e., you very very rarely see these 8"+ rain events), you might simply dry things out and recoat.

If it's likely to reoccur, french drains are an alternative. Here are some ideas and pictures for that:

Drain tile system

French drains in a basement

Lisa Miller · Answer

Thanks @Ben Skove

Everything around the house is either paved or cemented with an away slope. 7" of rain this month and another 1" today plus that tomorrow, I'm thinking it must be the water table. The home was built in 1940 and the original owner dug and cemented a trough along one outer wall and half the wall in question. Bedroom, the wet room, flat floor, laundry room trough, which seemed smart when I purchased as wash machines sometimes leak.  This situation however is the first, in the ten years I've owned it so again I am thinking water table.  What is  hydrostatic pressure? Sounds expensive.

7" Rain this month, Wet basement walls, what is the best sealer product?

Most Popular Reply