Hi. I am new to this forum and have spent some time reading many of the posts. Clearly, there are legitimate experts providing advice here and I am glad I found you. I would really appreciate your consideration of my problem and your advice.

Background:
I live in Northern NJ in a ranch house. We put an addition on the house 1 year ago which includes new living space on the main floor and a full basement below. The problem I am going to describe is limited to one wall in the new basement. The wall is 11' long and constructed with 12" deep block from top to bottom. About 5' of the wall is below grade and 4' is above grade.

After the block wall was built. A scratch coat (cementous material) was applied over the entire outside wall. Then the below grade areas of the outside were covered with ablack tar material. Not certain of what it was but they put it on with a paint roller. I then painted the above grade area of the outside wall with exterior paint for cement to match the painted foundation of the existing parts of the house. There is no drainage system on the outside of the wall (pea gravel, drainage pipes, etc). It was backfilled with dirt (fair amount of clay) that was excavated on the site.

I dug out a small area of dirt along the outside of the wall recently and found that the black tar is about 1.5 - 2 feet below the grade level. In hindsight, I remember asking the builder to raise the grade after his first cut at rough grading. I see now that the extra fill was put in without extra black tar first.

Problem Symptoms:
It is evident that moisture is getting into the wall because there is significant efflorescence on one area of the wall. The location is strange to me though. The below grade section of the wall does not have efflorescence. All of the efflorescence is on the above grade section, which is opposite the section I painted on the outside. Everytime it rains, the efflorescence areas get brighter/wetter (moist to touch, no water).

I see from all of the other posts that water problems (almost always) need to be fixed on the outsite of the wall and not the inside.

Question 1:
Why is the efflorescence only on the above grade section of the inside wall?????? If water is getting into the wall, wouldn't it go all the way to the bottom of the wall and cause efflorescence there instead? Is it possible that water isn't getting in at all and it is just moisture seeping through?

{B]Question 2:[/B]
Our builder is cooperative with me in discussing this and hopefully will work to resolve this, but I don't think he has the knowledge to understand exactly what's happening. He doesn't claim to be an expert here either. He did say that the missing one or two feet of black tar probably isn't the cause for this becuase it doesn't add much as far as water proofing and that the scratch coat is what helps (and that goes all the way up the wall). Do I need to be concerned about not having the black tar all the way up to the grade line? Could this be the entry point of the water/moisture?

Question 3:
How should we approach the overall problem?


Thank you very much for your help. I really appreciate it.

anyone else see the 'similarities' among quite a few recent posts? All just-happen to be here, foundations/waterproofing.

The subtleties of the waterproofing posts I've been reading on the forum are what make these problems interesting. They are very similar but also have many nuances which are not at all obvious to someone like me with no particular waterproofing knowledge or experience. For example, why does only the top of my wall have the effloresence? I haven't seen anything like this in the other posts. This is precisely why I am looking for advice on the forum.

Please let me know what you think about our situation.

Thank you

Licensed Waterproofer, Richard, wtrprf, anyone,

Any ideas for me? Please see my original post above.

Thank you.

No clue here. I've been trying to think of a way that the paint would affect the wall, with no success. Another possibility is that the mortar mix in that part of the wall is different, but that would not explain the efflorescence changing when it rains.

I'm baffled.

If the parge coat, the cement coating, is not sealed it is possible for moisture to transfer into the block wall. Cement is porous and in my opinion it should be sealed. The sealed part shows no sign of efflorecence, the unsealed part does. Apply a waterproof, not a damproofing product and see if this solves your problem.

Beg to differ. There are a million parged foundation walls which do not create effloresecence, and most of them are unpainted, while this one IS painted. Proper parging is quite adequate to keep water out of the wall without a´waterproofing. Perhaps the parging in this case is too thin...we have no way of knowing. If the mortar joints of the block wall behind the parging can be seen through the parge coat, then, in my opinion, it's too thin. If not, it's likely to be OK.

Richard, Wtrprfr1,

Thanks for replying. I wasn't sure what you meant by parged so I looked it up. Yes, this is what was done. They first put what they called the scratch coat with a notched trowel, then applied a second coat with a smooth trowel. Per Richard's comment, the parged foundation wall should be a good moisture barrier in itself. This concurs with what our general contractor said.

Could the above grade efflorescence on the inside wall have something to do with the fact that the painted outside wall gets a good amount of direct afternoon sunlight? The paint is a light/medium tan-ish color (not dark). If the outside of the wall is heated by the sun, could it cause some condensation on the inner wall if it is cooler? Not sure if this makes any sense or not. Some of the basement walls of the pre-existing house have similar sunlight exposure with no efflorescence.

Thank you.

Efflorescence is no more than salts which are carried out of the wall by escaping moisture. It is inanimate, even though it LOOKS like it grows similar to a fungus...but all it is is salt crystals.

I have wanted to say that the paint on the outside forces moisture to escape through the wall on the inside, but then I don't know why it doesn't happen also below grade.

I remain baffled...but there is a chance that it might simply stop...it may be the natural moisture escaping from the wall, and when the moisture has achieved balance, the efflorescence should stop. Some efflorescence is not unusual in new construction...the salts are contained in the masonry units and in the mortar mix, and the water used during construction, such as that used to mix mortar, provides the moisture.

By the way, the efflorescence can be removed by simply brushing, or there are commercial chemicals which remove it also. It is no more harmful than your salt shaker.

I'd suggest removing what has appeared so far, and note the progress of any new efflorescence. If it seems to be diminishing, then just wait it out and your problem will end. If it continues at the same rate, there is not only a constant source of moisture, but also a constant supply of salts, and that is very unlikely.

A two-coat parge ought to be an excellent job. A good parge coat will measure between 1/2 inch and 3/4 inch, and may even be an inch thick. A cheap parge will be barely more than a skim coat, and those are the ones where the individual blocks and mortar joints read through, especially in wet weather.

Short answer to your problem at this point is: you have nothing to lose by waiting and watching. The efflorescence might just stop.

http://www.buildingscienceseminars.com/handouts/BSD-108...oisture_Problems.pdf

water/moisture doesn't always go downwards-
hence your higher efflorescence...
porous materials suck (literally)
good luck

hotpepperpizza: I think you were on the right track when you mentioned that the outside wall receives a good amount of afternoon sunlight. The above grade portion of the wall gets more of an opportunity to dry out, making any water that was in it evaporate and bring the salts to crystallize at the surface. And since it can't easily go thru the parging and paint layers - it takes the path of least resistance and evaporates thru the interior wall. The lower portion of the wall does not dry out, hence, no efflorescence. Of course this all assumes that the lower portion of the wall is damp to touch after a rain as well.

Still you will have to determine the source of your water and the salts (whether its innate to the material or not) and the transport mechanism to really go about understanding the problem and its level of threat to the building, and designing an appropriate solution, as previously mentioned.

I stand by my original post. If a parge coat was adequate for waterproofing, than code would not require damproofing or waterproofing.