Dealing with a damp basement is annoying enough, but seeing water leaking through cracks in the foundation or mortar joints can feel downright overwhelming. The good news is there are solutions that help keep your space dry. Whether you're fighting a wet basement, tackling small leaks, or preparing your home for heavy rainfall, waterproofing your basement walls can make a huge difference.
What causes basement seepage?
- Poor exterior drainage: Clogged gutters or misdirected downspouts can lead water straight to your foundation.
- Hydrostatic pressure: Heavy, waterlogged soil presses against basement walls, forcing water through tiny cracks. How's your local water table?
- Cracks in foundation walls: Over time, settling or structural issues can create pathways for water through concrete walls. This also affects the structural integrity of your home.
- Poor grading: If your yard slopes toward the house, water naturally flows toward the foundation and causes basement leaks.
- Blocked or broken drainage systems: Malfunctioning perimeter drains or sump pumps can cause pooling water around the foundation.
How to Seal Your Basement Walls and Prevent Seepage
First things first, make necessary repairs:
- Check all of your gutters and downspouts. Make sure there are no clogs, and update the ends of your downspouts with extensions that run further from your home. When in doubt, have your gutters inspected.
- Improve your home's grading. Add compacted soil around the foundation of your home, sloping it away from the building. If moisture continues to flow towards the house, the improved grading will act as a barrier.
- Fix drains and sump pumps. If you know this is an issue, take necessary steps to fix it.
For Indoor Repairs, You'll Need
- Hydraulic cement
- Waterproofing masonry paint or sealant
- Wire brush
- Cleaning solution (e.g., trisodium phosphate)
- Concrete patching compound
- Paintbrushes, rollers, or sprayers
- Safety gear (gloves, goggles, mask)
- Bucket or sprayer for cleaning solution
- Flashlight (for inspecting cracks)
- Caulking gun (optional)
1. Inspect and Prepare the Walls
- Start by thoroughly inspecting your walls and basement floor for cracks, discoloration, or damp areas. Check the entire basement, using a flashlight to find hidden damage or wet spots.
- Clean the walls with a cleaning solution to remove dirt, grease, and mold growth. Allow the walls to dry completely.
- Scrub the walls with a wire brush to remove flaking or loose material.
2. Repair Cracks and Gaps
- Mix hydraulic cement according to the manufacturer’s instructions.
- Apply the cement to cracks and gaps in the concrete basement walls, pressing firmly to fill each opening. Smooth the surface as much as possible.
- Allow the cement to cure completely. This step blocks water pathways and stabilizes the wall.
3. Apply Waterproofing Paint or Sealant
- Choose a high-quality waterproofing paint or masonry waterproofing product designed for basements.You don't want to skimp on quality products for your waterproofing materials.
- Use a brush to coat corners and edges thoroughly. Rollers or sprayers can be used for larger areas.
- Apply at least two coats of paint, ensuring complete coverage. Allow drying time between coats as per the product’s guidelines.
4. Address Interior Moisture Issues
- To keep your basement dry, keep your sump pump clean and maintained.
- Insulate cold water pipes.
- Add a basement dehumidifier to combat high humidity levels.
- Check, repair or replace leaky basement windows.
5. If You Haven't Already, Address Exterior Drainage Issues
- Add downspout extensions direct water at least 6–10 feet away from the house.
- Check for clogged gutters and drainage channels and clean them regularly.
- Adjust the grading around your home to that the ground slopes away from the foundation.
- Consider drain tiles or a french drain to correct poor drainage.
FAQ
How do I know if my basement needs professional waterproofing?
If there is still water accumulation after sealing or you notice large structural cracks, it's time to call in a professional. Persistent issues or abnormally high water levels may require drainage system repairs, foundation repairs and stabilization, or advanced waterproofing solutions like exterior waterproofing. Structural damage and mildew growth can occur from a water leak or excess moisture if the larger problem isn't corrected.
Is waterproofing paint enough to stop seepage?
Waterproofing paint is an effective method for minor issues. Proper drainage can increase its effectiveness. But with heavy rain, the ground level around your home may become saturated and foundation leaks can overwhelm your efforts. If in doubt, call in a professional for more comprehensive waterproofing before the basement water damage and expensive repairs add up.
Can I waterproof my basement during wet weather?
It's tempting to fix the problem as soon as a basement moisture issue comes to your attention, but it's best to tackle waterproofing projects during dry weather. For successful application, walls need to be clean and dry to allow sealants and paints to adhere properly. Make sure that your sump pit is clear and try to correct improper drainage as you wait for dry weather to do your basement waterproofing.
