Hi, I have a crack on my basement from the bottom/center of the window sill all the way to the floor. When theres heavy rain (which is rt now)the bottom (about a foot & a half), leaks. I have to tear down the drywall (finish bedroom) to see where the crack was. Also, do I have to replace the bottom studs that got wet and have some mildew. Any suggestions on how to repair the crack and seal it. Hydraulic cement was recommended on Lowes web site. Or should I use epoxy injection "Crack Seal epoxy and polyurethane foam" Do-It-Yourself Crack Repair Kitfrom Applied Technologies?

Any advise/suggestion will be highly appreciated!

Do not try to seal the crack from inside the basement wall by injecting or appying any kind of sealant to the interior wall. You are wasting time and money. To get an adequate seal on a crack that penetrates the foundation wall, the seal MUST be applied to the outside and that involves excavation and exposure of the exterior wall. That way the weight of water/soil on the exterior of the basement wall WORKS FOR YOU, not against, pressing against the sealing material and holding it in place. In place of excavation, you might be able to use a sealant injector that has also penetrated the wall from the interior to the exterior so that when the sealant is applied, it coats the outside of the foundation wall, hopefully achieving the same effect as the first method described above, although I am doubtful of the outcome.

As to removal and replacement of studs and/or sole plates, that depends on whether rot has damaged the wood members or not. So called mildew, which is really mold (the only true mildews attack outdoor plants), is a sign that conditions are ripe for wet and dry rot, but severe damage may not have occurred yet, depending on how quickly you cleaned up and dried out the wall cavity and saturated members. Take a small-bladed screw driver with at least a six inch overall length, or a scratch awl, and poke and prod at the wood members that have been saturated up and down the saturation length and width. If the awl or screwdriver does not readily and easily penetrate the wood members you are concerned about then not enough damage has occurred to worry about.

On the other hand, if the probing reveals rotted wood 1/4" deep or more, get professional assistance in repairing the damaged members. Also, make sure the seal has worked so there are no more leaks and the affected cavity and parts are completely dry before replacing the interior finishes. Trapped water or dampness will cause further mold growth on wet surfaces. Clean the interior moldy surfaces with a mild bleach and detergent solution, and again let it dry before enclosing the framing.

Thanks a lot! Excellent suggestion! Your suggestion: "In place of excavation, you might be able to use a sealant injector that has also penetrated the wall from the interior to the exterior so that when the sealant is applied, it coats the outside of the foundation wall, hopefully achieving the same effect as the first method described above, although I am doubtful of the outcome." Any kind of special Sealant I should use for these or brand?

Agains, thanks a million!

The injection system I am familiar with is used in "mud-jacking" procedures to level a concrete slab or sidewalk. The contractor drills several 2" or 3" hole through the affected area and injects, under pressure, a concrete slurry that "jacks-up" the affected area to change the slope or pitch of the concrete structure. The slurry sets and cures and the repair is more or less permanent, absent weak soil settling or other problems. While such a procedure MIGHT be adapted to your circumstances, I don't know that such a system had been used for your purposes.

The hydraulic cement that Lowe's suggested comes as a powder and is quick drying, meaning that you have a very limited time to apply the material. Mixing and loading into any kind of injector equipment is not an option. This type of material would have to be directly applied to the exterior of the excavated wall.

I was brain-storming ideas for you when I mentioned injection. I don't think that such a process is currently available except as used in mud-jacking by a concrete contractor. The more I have thought about this, the less likely the procedure is applicable to your situation. To be successful and to ensure sealing, visible appplication of any sealant that I am aware of would be necessary. Sorry to raise your hopes on that score, but blind application of an injected sealant would likely not have desired effect.

That basically leaves the excavation process described in a previous post. You might be able to get additional ideas by checking with any local concrete contractors or foundation repair companies and see if they have any other methods that might serve. If you have any experienced building contractor buddies, they might have some additional information or ideas to save you from having to dig.