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iwannadoit 06-12-2012 12:37 PM

Humid but not wet dryloc enough?
Hi everyone,

First post! Bought this amazing 1961 Mid-Century modern house. I've had it with people coming in to give me estimates...

I pulled back 30yo paneling and discovered some efflorescence. Mostly in corners, and only in first block. There's also flooring (fake wood look) that's made of paper... given the look and the fact that only in the bathroom does it look like there any water damage (duh!) I feel confident the basement has never flooded.

Had two basement companies come in...they both wanted to sell me the trench+sump pump "deal". The prices ranged from $5500 to $11000. Given the disparity in pricing, I asked an Engineering company to come in... this guy said that because there's never been flooding in the basement, dryloc should be enough to stop the humidity (ranges around 65% without dehumidifier... walls are around 65% also.) Whereas the basement guys want to sell you "the system" I feel the engineering home improvement guy has an interest in selling you "the finish" because, well, they'd have to contract out the basement drying. He quoted me $25K to "finish" the basement (~1000sqft).

I feel I can't really trust either. And now I want to finish it myself because I have a 90's kitchen to do still...

That said, the basement looks good overall. The musty smell went away with the old finishes were demoed. The cinderblock has efflorescence in some corners but it's mostly limited to the bottom brick layer. Only half the basement is "below grade" (imagine a wedge into a hill that tapers toward the other end), and there are windows, so about 4.5ft to 5ft high "below grade.

Question is: can I just assume that since this house is 50yo and the floor has no cracks and no evidence of flooding that I can use dryloc? I read elsewhere here I can use self leveling polyurethane between the slab and the wall... is that right?

I don't want to finish a basement only to discover 4 years from now it was all for nil.
Also, I'm in East rains alot here and it's pretty humid in the summer altogether.

gregzoll 06-12-2012 12:42 PM

No, dryloc is not going to solve the problem. First thing is to get air moving down there. If it is not conditioned with the hvac system for the house, suggest doing so. If there is no a/c for the house, you need to get an exchange of air, and air circulating.

Trucon01 06-12-2012 12:57 PM

Testing the humidity was good. You can also tape all four sides of a square piece of alum. foil to the wall and check it after a few days. If the wall is damp, you have seepage, if you have water on the front of the foil, you have a moisture / humidity issue.

I'm about to use Radon Seal AND Drylok Extreme, Radon Seal first, on my basement walls.

the1german 06-12-2012 01:19 PM

3 Attachment(s)
Hello! Welcome to the forum. I live in KY and can relate to the weather. I have a very similar basement set-up and am near completion of finishing it. I did have water on a few occasions and did have a company come in to put in a channel around the inside perimeter and sump pump and couldn't have been happier. In addition I painted the cinderblocks with 2 coats of the more expensive (premier, I think) dry-lock before framing it.

Between the two, I am sure that I will never have another moisture issue. I know that the basement channel/ sump pump is not for everyone, especially because it only manages the water, but it was by far the better deal of what I had presented to me. Company was done in 4 days or so and I loved their work. They were clean, fast and efficient. No complaints. Cost me about $5,500 or so.

As an alternative, after seeing what they did, I would now feel comfortable to install my own sump pump. Dig a 2-3 foot deep hole at the lowest part of your basement, some gravel, the sump pump in its bucket housing etc, top it off with concrete and pipe it to the outside. Just in case. I think my sump pump alone would take care of 99% of the issues.

The issue I had was mostly static pressure from below and water accumulation in the corners.

See the pictures. They were taken just days after a major rain, and proved to me that I had to have the basement system.


the1german 06-12-2012 01:57 PM

Another note, a product called V-Seal seals existing concrete floors which I also used on the floor. I put down laminate wood flooring over Delta-FL. I think I did everything I could to prevent a water issue from ruining the basement.

The other half that had been finished by previous owner was no longer in a condition to be lived in: eg carpet & water.

Better safe than sorry was my thinking.

Trucon01 06-12-2012 02:00 PM

Yea, I had been thinking about using the Delta-FL as well. I'm an overkill type person, if you couldn't tell...

Gary in WA 06-13-2012 12:16 AM

If finishing the basement for living space, I would suggest:

Use foamboard on the walls rather than Drylock, unless a water problem is evident. If so, drylock and a drain system to remove the water collected because the drylock stops/redirects moisture to collect/pool in the bottom, at the wall/footing joint. Add to that the empty cells in CMU's collect water, no wonder it only is wet at the first course. Actually, water can wick upward and come out inside higher-up, falsely giving you the idea a leak is there. Without water signs, no drylock, just foamboard, thickness as per location;

Delta will stop the moisture but not the heat-loss, that is the second reason for f.b. Check out the difference in heat-loss with different thickness f.b. on walls and floor in this paper, cruise around on it: http://www.buildingfoundation.umn.ed...timum-main.htm
Another heat-loss calc. where they don't even use XPS:
Also: add sill sealer under p.t. bottom plate for thermal/air/capillary break:
fire-stopping at wall top and every 10' lineally, f.b. the rim joists: and ADA the drywall:
Air seal with the glue pattern as well.
It is important to use a thermal break at the wall/slab joint, as well as f.b. under the perimeter of slab. Some comparisons on page 69;


Ameri-Dry Guy 06-18-2012 10:06 AM

The Problem with Paint On Sealers
There are a few problems I have with "paint on sealers". One is that they need to be re-applied every few years. Also, if the product buckles, chips, or peels (and it does happen in high moisture areas), the wall will need to be completely stripped and/or sand blasted. Therefore, "paint on sealers" can actually be counter-productive.

rezza 07-30-2013 02:44 AM

I agree with you . I am currently working on a home in China and i installed a dimpled membrane on the basement concrete wall. We face hot hot summers reaching 35 to 40 degrees. and winter months around 0 . So i face 2 problems. 1 humid wet basement interior walls. and heat loss do to no insulation construction practice methods in interior homes in China. So i applied the trench system with the dimpled membrane , i wanted to illuminate any moisture seeping through the concrete walls as much as i could. 2nd i want to apply a metal frame wall with roxul batt insulation and waterproof drywall. but i have a question . I usually would apply a vapor barrier poly 6mm before boarding so that the humidity left in the home cannot travel in the wall cavity. Any feed back? i also went over kill on installing a di humidifier vent in every room of the basement and a dimpled tile membrane on the floor and carpet membrane in the audio room. I would like to here any other suggestion you may have since you are also into the over kill .

stadry 07-30-2013 05:31 PM

by now everyone ( 'cept newbies who don't research this forum ), knows what i think of this product :furious: Ameri-Dry Guy, whoever said this was a paint-on sealer other'n the label & the apron/vest sales guys ? btw, we use aurand's elec scarifiers to prep walls & remove this junk,,, xypex & kryton are far superior products but, as always, PREP is the key to good material performance provided the mtl's worth a damn to begin AND the right mtl's selected.

blister ' is probably a better term than ' buckles ' but that's just my opinion,,, others may disagree but they're wrong :laughing:

ps - in 35yrs, i have yet to see it applied to an interior conc bsmt wall

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