I have a late 70's split-entry, so my basement foundation wall is roughly 4 feet under the ground. The basement is finished with wood framing, spray foam insulation, and sheetock. Recent heavy rains have caused me to get water in one room at the end of the house - this is the gable end, so gutters are not the answer. I had a foundation repair "expert" take a look, and all he could say is that water must be sitting against the foundation, and finding a way in somehow, but with the interior walls finished, it's impossible to say exactly where the water is coming in. It seems to be traveling along the bottom plate and leaking through where one 2x4 meets another. He suggested digging to the footings, cleaning the block wall, priming it, then attaching a rubber membrane, then platen on top of that. Is this the best option for exterior waterproofing?
The water issue has only happened twice, each time when we had considerable rain, so I don't need to fix it tomorrow, but I definitely want to fix it within the next few months. I am looking for a permanent (and preferably diy) solution. It seems that every article I read about similar water problems, the author has a different opinion about cause and solution.
I also considered an exterior drain tile, I think this may also be called a French drain. My lot does not have the necessary slope to easily get rid of any water an exterior drain system might collect, but there could be other options. I don't know anything about these kinds of drain systems, so I'm open to suggestions and recommendations.
More details following the answer by DA01 - Thanks
I have gutter extensions that are about 4' long, which I believe are sufficient. As for the grade, this is something that can be improved. I would estimate the current grade to be about 2-3 inches of slope over a 4' span (this slopes away from the house), but I'm hoping to bring in dirt and increase the slope a few more inches.
It would be great if all I had to do to eliminate the water problem is improve the slope of the grade. But on the other hand, while I'm going through the trouble of hauling in dirt and re-seeding, does it make sense to just do it right and waterproof the foundation at the same time? This obviously adds a great deal of expense, however. Also, would waterproofing the foundation alone be enough? Or do I also have to add a drainage system at the same time?
Thank you in advance.