Flooded Basement and Leaking Basement Wall Repairs in New Jersey

 Dear Doctor Energy Smart,
The grading around my house is inadequate. In fact,it slopes towards the house on one side where a concrete walkway was improperly poured. I am thinking about tearing up this walkway, but need to know the best way to regrade the sides of the house. I am getting conflicting info from landscapers and from sources on the internet. I believe that this will alleviate the problem of moisture showing up in my basement which seems to be most pronounced on the worst graded side of the house. Jt from Somerset County

Your common senses are correct... eliminate the obvious first. Be sure that your gutters (if any) are collecting the roof water and directing it away from the house. The poorly graded walk is an obvious suspect, and should be repaired.

If the source of the problem water is below the ground, neither of these solutions will fully solve the problem. Movement of ground water can be opposite the apparent grade in some circumstances.
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Dear Doctor Energy Smart,
Hello!  My question is concerning a house I am looking at purchasing. The problem is the basement did leak 3 years ago but apparently seems to be good for now. The basement wall where the water was entering was repaired from the inside of the house. Do you feel that this is a temporary fix or a permanent one? Is repairing the basement wall from the inside as effective as repairing from the outside?
There is a cement slab on the outside of the house right where the water was entering. Would I be able to break the concrete up with a jackhammer if need be or not? I can't tell if the wall is permanently fixed since the vendor did not re-insulate the exterior wall and put drywall back up. There is no smell of dampness or moisture in the basement. Thanks.   
gw

It is impossible to say if the repair is permanent, since we can't duplicate the conditions that caused the original basementleak. Under the right conditions, any basementfoundation will leak, so there is no exacting answer to your first question. The fact that you can't look at the repair is not ideal, but is common in finished basements where the owners want to get on with living their enjoyment of the room. You could hardly expect them to leave the repaired wall open forever, or to cut open the wall for you unless you have committed to buy the house first.

Exterior waterproofing or the installation of a drainage system at the base of the foundation walls is the most thorough repair for a re-occurring water problem, but it may be an overreaching  solution if the original leak was caused by a special circumstance, such as a broken or overflowing gutter or unusually heavy rainfall. Perhaps you should try to find out from the seller how, when, and why the leak occurred. The hole or crack in the wall may have been there for years, only causing a problem under the "unusual" circumstance!

The cement slab you mention could be a part of the problem if it is not sloped away from the basement foundation. If there is a slope away from the foundation, even one that is a slight, the slab should keep the foundation dryer by redirecting water away from it. An acceptable slope for a new slab near an existing structure is approximately one inch of slope for every ten feet of slab. A slab can be raised to increase the slope, it can be coated with new cement to the same effect, or broken apart and redone. It really depends on how large the slab is and how much work you want to get involved in!

I have done many small crack repairs with various cement patching products. When done properly, these repairs can last many years... sometimes long enough to be considered permanent. If you decide that you want to open the wall to inspect the patch, you might want to add a waterproofing coating (not a sealer) over the repaired area before closing the wall. Over treating the repair is good!

Oh,and be sure to choose a below grade waterproofing product
 
Dear Doctor Energy Smart,
We have a 55 year old house, with a basement 75% in-the-ground. I would like to put up finished walls. However, the basement has a moisture problem with efflorescence. I have treated the efflorescence with muriatic acid, with Zypex and with bleach at different times through the last few years but the efflorescence keeps coming back. The basement has good ventilation and we intend on putting radiant heat in the floor. The basement is used year-round and is kept very warm in the winter. If I treat the efflorescence once again and dry out the walls, can I put up the vapor barrier, then 2x4 walls with insulation?
rt

You know efflorescence is a mineral deposit caused by the migration of mineral-rich water through your basement walls. In new concrete work, efflorescence can be a short-term problem that may disappear over time as the new walls dry out. However, if this is a long-term problem there are two great ways to eliminate it.

Removing all traces of the efflorescence by scrubbing and cleaning the basement wall with muriatic acid (most hazardous) or phosphoric acid (less dangerous), drying the walls.They do not have to be fully moisture free... just not wet) and applying a quality below-grade cement-based waterproofing paint will definitely diminish the stain, and may likely eliminate the problem. Be warned... if other sealers or paint products have been applied to the walls, there is the possibility that the waterproofing paint will not adhere and the results may be disappointing.

You need to keep in mind that these waterproofing products are not designed to stop flowing water. Actual leaks must be stopped either by sealing them inside with a concrete patching compound (with a high risk of eventual failure) or doing some more labor-intensive work outside of your home. The solution could be as easy as cleaning your gutters. Then again, it could require diverting the water through regrading dirt etc(if the source is surface water) or even installing a drain system at the base of your foundation. A professional evaluation might be advisable so you can assess all your options.
Once you have eliminated most of the moisture moving through the walls, then and only then can you install your vapor barrier and walls. Yes... even after the waterproofing steps you must still install a vapor barrier because there will still be some low level of moisture movement through the walls. You don't have to worry about mildew… the vapor barrier will form a "stabilizing zone" that will not promote mildew growth… there is nothing for the mildew to feed on!

Dow Chemical offers a somewhat different system, using specially slotted 2'x8' Styrofoam panels that can accommodate a 1"x3" nailer... suitable for the installation of wallboard. Using "green" water-resistant wallboard... at least for the bottom half of the walls... would be advisable. The one drawback to this system is that all your electrical wiring must be on the surface... visit your local home store for the scoop on surface wiring systems. Ain't competition grand!

Don't throw away your dehumidifier. Any below grade area that is anything less than swimming-pool-sealed will have some moisture leaks... especially in the warmer months... and a dehumidifier will keep the air moisture level acceptably low. Again, and I can't reiterate this enough, you are doing this to protect your property and your investment in what will be a wonderful renovation!

If you don't take these extra steps you will regret it. I have seen too many basement renovations that did not take into account the damaging effects of moisture and I have taken roomfuls of once-nice furniture to the dump because of permanent mildew damage. You have to be proactive so that you not only keep the value of your home but increase it through wise use of your hard-earned money!

Dear Lp,
I have a ground water leak at my water service pipes during periods of heavy rain. I have a poured concrete wall foundation. This pipe enters approximately 6' below grade. It appears that when enough water-pressure is achieved in the ground water, it forcefully shoots along the pipe and into the basement.
I have it blocked to stop the spray and allow it to run down the wall to the floor joint, where it enters the sump drainage system. However, I would like to finish the basement so I am looking for a way to stop the leak. This is not a large hole, so expanding foams probably will not work. Would applying a marine epoxy with a syringe into the pipe/wall joint when dry form a permanent stop for this leak? Do you have a different recommendation? I have seen you recommend goop for other types of leaks, but I don't know if it would withstand the hydroscopic pressure.
Nk from Randolph NJ,

Any breach through a below-grade wall has the potential for leakage. This includes water pipes, electrical wiring and holes from the metal ties that held the concrete forms together during the pouring of the foundation.

There are a number of products that are designed to stop leaks in concrete walls, the best from a do-it-yourself perspective being hydraulic cement... a.k.a. "Water Plug". This Portland cement product sets quickly and expands while drying. It sticks tenaciously to new or old concrete and will provide an excellent water seal between metal pipe and concrete... provided the metal is not too dirty!

Hydraulic cement needs at least an inch or two of "depth" and a half inch of width in order for the cement to have sufficient and reliable holding strength. Carefully chisel or drill out (with a masonry bit, of course) an adequate width and depth of concrete surrounding the pipe. Rinse off any dust or dirt and, while the wall is damp, apply the hydraulic cement with a metal or wooden tool, packing it tightly around the pipe. You can smooth the patch with a damp tool but work fast, since you will only have a minute or two before the initial hardening occurs. Once the patch hardens, your leak should be permanently stopped. The ground water will still be there, of course, but it will find its way to your drainage system instead of your basement floor!

I would not use marine epoxy in this specific instance. Expanding foam may or may not work in this instance, again due to the depth of the cavity to be filled. Not that there isn't a place for expanding polyurethane foam in sealing leaks in concrete walls. For example, it is one of the few sure and easy solutions for leakage through a pipe containing electrical wiring, such as from a well pump or underground wiring for light posts. The foam will not damage the wiring and will expand to fill every nook and cranny in the pipe!

And forget Goop! Though dry Goop is waterproof, it is not designed to stop leaks, especially under pressure. Doc