Evaluate the perimeter of your house
As we all know, water runs downhill. Or better yet, that’s what you want it to do. If the ground around your house is flat or worse yet, sloping toward your house, this is really bad in terms of having a dry basement. In this case, you will have to bring in some fill (ugly dirt) and make the ground slope away from your house; at least eight feet. You also need to ensure that the water can continue to run off. Water flowing towards your house is the major cause of basement flooding, in my experience.
Have you ever noticed the amount of water that comes from your gutters? WOW, that’s a lot of water! If you don’t have gutters, or if your downspouts end at the edge of your house, you’re not doing your basement any good. All you are doing is pushing that water straight down into the foundation.
Try to waterproof your walls with a product such as Drylok or Xypex
If you have minor leaks, and I mean minor leaks, you can use a product like Drylok or Xypex. This is not the cure of all cures by no means. I have never seen this product work, but I know others have. First, you need to clean the heck out of the inside wall and make sure it’s really dry. Once done, use a heavy-duty brush and start painting. Using this method, you are still letting water pass through the foundation which is really bad. In my opinion, the only way to stop leaks is from the outside.
If your foundation has big cracks and holes, these really need to fix before anything else. Cracks can be fixed simply by using a caulk made for concrete. Larger cracks would need to use a Mortar mix with a concrete bonding adhesive, this will help bond to exist concrete. After your patch has dried, you will want to brush some foundation tar over the area covering well into the existing tarred area. Of course, this would be below ground level.
Consider installing a sump.
This is essentially a hole in your basement floor which contains a pump. Your concrete floor is about 4 inches thick and then you have about 4 more inches of stone under the concrete. When water collects under the floor, the stone acts as a large reservoir. There could be a few thousand gallons of water there long before you see any in your basement. By installing a pump in the floor, about two feet down, you could collect the water and then pump it out. OK, I know in my own house, the pump may not need to go on for a few years. But when it does, I know if it didn’t have it, I would’ve had a big problem. A few important things to know is to always make the hole at least 20 inches wide and about 24 inches deep. This ensures your pump will stay submerged deep enough to help keep it cool and will also help it to collect as much water as it can.
If your house was built after circa 1972, chances are you have footing drains. Footing drains are 4-inch perforated pipes that run around your foundation, collecting the water at the footing level. At one corner of the house, there is usually a tee connecting to more than 4-inch solid pipe going to the lowest point of YOUR property. You may have seen this before while out gardening or cutting the grass. Make sure it’s clear at all times. Next time it’s raining and the water table is high, go out and check it to make sure there is water coming out of it and it’s free-flowing. If it’s not free-flowing you may need to check the length of it to find the clog and clear it out as well.