Inspecting homes in the Baltimore area, some of the most common defects I encounter involve wet basements. It can be a tough problem to solve, particularly in an older home. But, too often people ignore the root problems and treat the symptoms. No amount of drain tile, waterproofing goop or “waterproof” subfloor will solve a water issue that starts outside.
The first thing I look at during the home inspection is the downspouts. If your downspouts are draining right next to a foundation wall, of course the water will find its way inside. A minimum of a 5-6’ extension is recommended to carry water away.
The next consideration is grading. Grading is simply the relationship of the height of the ground around a home to the home. Ideally, the home sits at the high point of a property and the ground slopes away on all sides. If the ground slopes toward the property, then water problems are likely. If you take a close look at the photo above, you can see that the sidewalk slopes toward the house, and someone has tried to use expanding foam insulation to stop the water. Unfortunately, that material is from waterproof, indeed, it’s more like a sponge. In that case, it was clear from the mold in the newly remolded basement that it wasn’t working. The pooling water wasn’t doing the masonry steps any good either. Fixing the grade is the best solution, possibly with the addition of a concrete curb or sluice to carry water away.
In extreme situations, it may be necessary to add French drains (corrugated plastic pipe in a trench full of crushed stone) to the exterior of the house to carry the water away.
Water issues are a huge topic and it’s impossible to cover all the permutations in one short article. But, when you’re looking at a house, stand back and think like a rain drop. If water can run toward the house, it will. So help it run away and stay dry!