Grading Away From House and Basement Water Problems

Grading Away From House and Basement Water Problems

We live in a ranch house in Delaware.
Original house was on a cement slab. We added an addition in 1965. There is a cement sidewalk across the front of the addition and down that side of house.

There is also a patio on back of the addition and a gas meter on right side near front corner. Sidewalk has cracked there. Moisture neglect in crawlspace has caused major mold and instability of some of the joists and one beam more than the other. We are planning to have Basement Systems Inc. do mold cleanup, structural reinforcement, white Cleanspace. However, we have to solve the water intrusion problem. We are getting recommendations and estimates.

Although we are having the sidewalk removed and soil graded away from house, we are not able to grade a lot due to close proximity of side neighbors. We need a recommendation...excavate down cement blocks from below sill plate to below crust coat, or is that extreme?

After removing the sidewalk, how far down should we excavate? Seal? Seal with what? Add a membrane? This whole thing is overwhelming to me. Someday I will deal with grading completely around house, but now I need to focus on side near crawlspace first. Any guidance will be greatly appreciated.

ANSWER

This is way to complicated to give advice via one email. I would have to see a survey, get topographical information and also see pictures before I would recommend solutions.

As far as sealing goes, I don't know what the problem is unless the blocks are cracked or unstable. If that is the case, you might consider contacting an engineering firm. If you just want it sealed, call a
company that specializes in waterproofing basements. A sump pump might also be a solution.

Just as important is the grading away from the house, which you mentioned. Installing french drains that lead to another area is one way you could go if the area is narrow. However all you really need is to grade at 1/4" per foot. That means that the area adjacent to your house should be a minimum of 1" higher than the grade 4 feet away. Plantings should also help since their roots take up some of the water.

If I can be of further help, let me know.

Susan