Waterproofing and sump pump

Hello, thank you for posting the project. Small water leaks through basement walls during heavy rain are usually caused by foundation cracks or pressure from outside soil. I specialize in waterproofing and crack injection. If you can send a few photos of the leaking area and where the water appears, I can better understand the issue and suggest the best.

Even though the basement has been professionally waterproofed and is equipped with a sump pump, unusually wet conditions—such as a heavy or prolonged spring thaw—can still allow small amounts of water to seep through foundation walls. This may happen if groundwater levels rise beyond normal capacity, if there are minor cracks or weaknesses in the foundation, or if the exterior drainage system becomes overwhelmed. It’s important to monitor the situation closely. Ensure the sump pump is functioning properly, check that downspouts and grading are directing water away from the foundation, and inspect for any visible cracks or deterioration. If the issue persists or worsens, it may be necessary to have a professional reassess the waterproofing system and foundation to identify any areas that require repair or improvement.

Hi and thank you for the question, it can be incredibly frustrating to invest in a professional waterproofing system only to see water creeping back in during the spring thaw. When a "waterproofed" basement with a working sump pump still shows water coming through the walls, it usually points to a few specific issues depending on exactly how the basement was waterproofed. Our team would need to determine what root cause is and it depends heavily on whether your professional system was installed on the inside or the outside. If you have an Interior drainage system (Weeping tile/trench under the basement floor) these are technically "water management," not water prevention. They allow water to enter around the footing and or the foundation wall, drop down behind a dimpled plastic dimple board, and flow into the sump pump. If you are seeing water on the walls, it means water is either entering above the plastic barrier, or the barrier wasn't sealed correctly at the top, allowing water to escape into your drywall or living space. If you have an Exterior waterproofing system (Excavation, rubberized coating, dimple board outside) An exterior system is designed to stop 100% of water from touching the concrete. If water is coming through the wall, the system has either failed (a tear in the membrane), or water is getting in over the top of the system. you can check for leaks coming in over (The Most Common Spring Culprit) During a wet spring with heavy snowmelt and rain, the ground becomes fully saturated. If the soil around your house has settled and is grading toward your foundation, water will pool against the house. If water pools higher than your concrete foundation line (where the concrete meets the brick or siding), it will literally pour down the inside of the wall, bypassing your waterproofing membrane entirely. if you have any other questions we would be more than happy to provide further information or a free inspection.

Hello, Was your waterproofing installed inside the basement or outside? If inside, water seeping through cracks in the foundation are normal and the water should drain down to the footings/trench then brought outside via your sump pump. As others have said cracks in foundation walls can be repaired. There are numerous products and systems out there for repairing foundation cracks, some better than others. If waterproofing was installed on the outside of your basement, then you have a deficiency in your waterproofing system that will need to be remedied either from the outside or inside.

If water is still coming through the walls, it can indicate that the original system isn’t fully relieving the exterior water pressure, or there may be areas where the waterproofing has weakened or was never fully addressed. Sometimes it’s as simple as correcting drainage, other times it requires updating or modifying the existing system — it really depends on how the original work was done and current site conditions.

What you’re describing usually means the system is getting overwhelmed a bit with how wet this spring has been, not necessarily that it’s failed. If it’s just minor seepage and everything else is working the way it should, I wouldn’t jump straight to redoing exterior drainage. That gets expensive fast and isn’t always necessary for something that only shows up in rare conditions. A good middle-ground is adding a secondary layer on the inside. Products like Xypex or Penetron can help seal the concrete and deal with that small amount of moisture when things get pushed to the limit. That said, I’d still take a quick look at the basics first, just to be safe. Make sure the sump is keeping up and that water is being pushed well away from the house. If all of that checks out, then this is a pretty reasonable way to tighten things up without going down the road of major rework.