Foundation issues can be caused in places where the water is not being properly controlled around the house. Bad grading and uncontrolled water around the house leads to more movement when it eventually dries out. Poor gutter management and negative grading are the major culprits for this type of foundation failure.
Negative grading means the landscaping slopes towards the house rather than the water flowing away from the structure.
If the soil around your house is mostly clay and kept in a more saturated state because of poor grading or uncontrolled rain water from gutters, it will continue to hold more and more water, thus expanding and swelling, especially during the wet seasons.
This expanded clay soil is going to be pushing up higher than normal on your foundation.
When clay soil has excessive moisture to expand it than once the dry season starts there is a larger volume swing that will take place.
If the grade were properly controlled around the house and rain water wasn’t flowing towards the house, you would still have moisture in the clay soil, however when it dries out, even though the volume would still change, the starting point would be a lesser volume because it hasn’t been saturated for as long.
Rain water from gutters discharging right against the foundation where the grade is negative is encouraged to flow back towards the structure. Water can then penetrate the crawlspace or basement.
When we see a home with a wet foundation from negative grading or gutters, our first solution is to control the water. We do this by correcting the negative grade around the perimeter, getting drains on the downspouts to direct the water away from the house,
or a combination of both.
The grading may be carving swells in the yard so that the water flows away from the house or it may be bringing in soil to build up a ramp toward the house so that it slopes away or a combination of the two.
Sometimes you don’t want to add the additional soil against the house for load reasons. There are times when extra load against the house is ok depending on how high the crawlspace or how low the crawlspace is, relevant to the outside.
What should a homeowner do if water is getting into a crawlspace or basement?
First stop water from reaching the crawlspace/basement.
There are a few ways to get rid of the water.
Install interior drains. You can hire a company to go in and dig a perimeter drain, install a sump pump, and pump it out any water that travels through the foundation block. That’s fine for managing the water when it gets to the crawlspace but the core problem is not that you have water there but that you have water getting there. Ideally you’d like to stop the water on the outside of the house so it never gets to the crawlspace or basement.
Typically the way we handle keeping water from penetrating a foundation is with gravity drains on the exterior. Trench drains in the yard intercept the water or foundation drains immediately against the foundation or basement wall are two effective techniques we employ. Fountain drains include sealing the wall with a waterproof membrane and putting in a drain to allow the water to flow out via gravity to a low place in the yard or down
The advantage to both drains is gravity never fails and you are not relying on electricity to make sure that the water gets away.
If you have a sump pump with a heavy rain or hurricane, you are probably going to be without power. The sump pump will not function as intended without electricity. Many sump pumps come with battery backups, however, batteries will only last so long.
By not correcting water drainage or simply trying to manage the water using a sump pump, your problem has not been solved.
Allowing water to penetrate the crawlspace or basement causes your house to be susceptible to foundation failure.
Conclusion: Keep the water on the outside and flowing away from your house.