[decijp]

I am selling a house in Cincinnati, OH. The house was built in 1962. I bought it in 2001. I never had a problem with the basement leaking. When I bought the house, there were diagonal cracks, which I was told were no problem by my inspector.

About 6 weeks ago, an inspector noted efflorescence in the basement and implied that this was a sign of the basement leaking. (He identified a number of clear defects, which I have since fixed. His buyer has moved on.) I hired an engineer to look at the back wall of the basement, and he found about 1/2 " of inward tilt and recommended Pilasters, which have been installed. Since the report, we have had a fair amount of rain in Cincinnati, with, of course, no water in the basement. I videotaped the moist conditions outside and the dryness inside and documented the date and time. Also, the son of the former owner (an engineer who graduated from the naval academy) has written a statement that the basement never leaked from 1962 through 2001.

I realize as an owner, my statements regarding the non-leakage of the basement, are going to be taken with a grain of salt by buyers. My question is whether there is a scientific explanation for the efflorescence that is consistent with my experience and that of the former occupants, that the basement does not leak.

Thanks for any assistance that can be given.

 

[joed]

Effervescence comes from moisture. your basement may not be leaking but there is still moisture.

 

[decijp]

Effervescence comes from moisture. your basement may not be leaking but there is still moisture.

Thanks, I understand that. My question is how to potentially distinguish between efflorescence that is result of leaking and efflorescence that is not the result of leaks.

 

[stadry]

no, you don't understand joe,,, moisture IS either liquid OR vapor coming IN THRU your very fine basement wall,,, capiche now ? to my knowledge, there's no way to determine which is which & we do this work for a living,,, however you MAY be asking indirectly how to differentiate between liquid & vapor - that's easily done that,,, the next time it rains heavily for a period of time & the ground outside becomes saturated, go downstairs w/towel & wet/dry vac,,, if you need neither, it MAY be vapor,,, if you need both, its liquid

happy to help

 

[Bud9051]

Both joe and stadry are correct. What you and the engineer son are missing is that moisture vapor can and is passing right through those walls and probably the floor all of the time. In 62 they did not practice the methods used today to build a truly dry basement and those methods are extensive. The first link below is more about slabs of concrete as opposed to basements, but it provides some of the science involved. The second link has some great explanation as well. Both links include additional references which I encourage you to investigate.
http://buildingscience.com/documents/insights/bsi-003-concrete-floor-problems?full_view=1
http://buildingscience.com/document...ndations-moisture-resistant-construction/view

Your bottom line is, yes you have some moisture as virtually all basements will have, but the minimal amount of efflorescence is telling you "it is minimal". Unfortunately, it will always be there as it originates from the moist soil outside and there is no way to back up and isolate the foundation from that moisture.

If you or a future owner wish to finish that basement it simply means you would need to manage that moisture. In many cases you would simply avoid using a vapor barrier and allow the wall to dry to the inside through a vapor retarder, something like an inch or two of rigid foam.

I'll let you read.

Bud

 

[stadry]

wet runs to dry & cold runs to heat - hyskoul fizix, remember ?

 

[carpdad]

Concrete has chemicals/minerals in it that is dissolved by water. Efflorescence is dried minerals. It is a sign of water. Check outside grading, gutter leaders, how the downspout water is channeled, animal holes, fence and gate posts, etc. Often the flower bed against the foundation admits and holds a lot of water.

 

[decijp]

Bud, "If you or a future owner wish to finish that basement it simply means you would need to manage that moisture. In many cases you would simply avoid using a vapor barrier and allow the wall to dry to the inside through a vapor retarder, something like an inch or two of rigid foam."

The basement was finished when I bought it. There were and are no leaks. There is obviously a small amount of moisture in the walls, but it has no functional significance. I am hoping to find an explanation for what has actually happened -- five or six small splotches of efflorescence and no leaks or actual water in the basement.

 

[Daniel Holzman]

I believe you already have the explanation, which has been explained in several posts on this thread. Moisture moves through concrete in the form of capillary water, and water vapor. If the ground outside is moist, as it will be except perhaps in the Atacama desert, the vapor pressure outside the house is likely higher than the vapor pressure inside the house, so moisture moves from outside to inside, either as vapor or as capillary water. In either case, you don't see it.

The moisture dissolves minerals in the concrete, which then deposit on the inside face of the wall as the water evaporates. This is totally normal for concrete, and is not a sign of problems or issues. If it were my house, I would not do anything about it. I realize that individuals considering purchase of the house may dislike the presence of efflorescence, and you may lose a sale. If you think the marginal additional value of having more buyers is worth the cost, you could undertake a program of wall treatment with a vapor barrier (on the outside of the wall). Again, I would not do it personally, since I have no problem with minimal efflorescence, but it's your money. Alternatively I suppose you could grind off the efflorescence and forget to mention it to prospective buyers, let their inspector note the "problem".

 

[Bud9051]

@decijp " There were and are no leaks. There is obviously a small amount of moisture in the walls, but it has no functional significance."
Yes there is some moisture in the wall, but it IS SIGNIFICANT, as it can lead to mold.

I usually see efflorescence on concrete. You are indication the basement is finished, so where is the efflorescence showing up? Are the walls finished, studs, insulation, and drywall? Maybe the following link will offer some answers you will believe:
http://buildingscience.com/documents/digests/bsd-103-understanding-basements?full_view=1

Bud

 

[Tscarborough]

Is the efflorescence on the new pilaster block or the old block?

 

[decijp]

Bud: "Yes there is some moisture in the wall, but it IS SIGNIFICANT, as it can lead to mold."

At one time there was a small amount of mold under a wall below a window well that leaked. (it was in a depression and I built up the area around the window well and solved the problem. No problems or mold since then) This window well was on a different wall than where the efflorescence was. I will later post a diagram of the basement, which is half finished. My house is on a small mound about 15 feet above the street and at least 75% of the water simply drains away from the basement and the house. The back wall, which has the minor efflorescence, is adjacent to a low spot. However, water never accumulates on the ground above the back wall, and as I have said repeatedly, there has been no leaking water. Also, there is no mold on this wall.

I would add that I had my office in the basement the last 4 years that I lived there and also my workout equipment. (Exercised at least 4 days a week). Additionally, my then 11-year-old son had mild asthma (which disappeared about 2 years ago while he was in the house) and he (as well as I) never experienced problems while in the basement. So, for all but the very most sensitive people, any tiny amounts of mold (which according to Ohio Residential Disclosure form is present in all houses) should be irrelevant.

Thanks for your link. Although it was a bit complicated, it was useful.

I would add that, in my opinion, unless real unsolved problems are found (there will be an inspection) that some of the comments are advocating a bit of over-engineering. The house was built in 1962, and there has been no leaking and no significant mold problems. I spent $2,500 on Pilasters to alleviate concerns among buyers even though I would not have spent that money if I had continued to live in the house. If we were starting from scratch there would be a reason to provide additional moisture protection. However, we are not starting from scratch, and any future potential problems are highly unlikely and merely hypothetical based on 56 years without moisture problems inside the basement.

 

[decijp]

Tscar: "the efflorescence on the new pilaster block or the old block?"

The efflorescence is on the wall where the Pilasters were placed. My basement has concrete walls not blocks. Hope to post diagram of basement and drainage this afternoon.

 

[decijp]

To supplement. The efflorescence is on the back concrete wall that has not been finished.

 

[decijp]

Here is the diagram of the basement that I have been discussing.