Having a dry, usable basement is a dream for many homeowners. However, if you have a brick basement floor, achieving that goal can be challenging. Water seepage through brick and mortar is a common problem that can lead to a variety of issues such as mold growth, musty odors, and damaged possessions. Thankfully, with the right waterproofing techniques, you can successfully transform your wet basement into a dry, livable space.
In this comprehensive guide, we will discuss the causes of water seepage in brick basement floors, evaluate waterproofing options, outline installation steps, and provide tips for proper maintenance. With the strategies outlined below, you’ll be well on your way to a drier, healthier basement.
Causes of Water Seepage in Brick Basement Floors
Before examining waterproofing solutions, it’s important to understand why brick basement floors allow water intrusion in the first place. Here are some of the most common causes:
Porous Bricks and Mortar
The brick and mortar materials themselves are porous, which allows water to seep through tiny pores or cracks. Over time, bricks can degrade, crack, or shift, opening up larger entry points for water.
No Vapor Barrier
Older brick foundations often lack a vapor barrier underneath. A vapor barrier is a plastic or rubber membrane that blocks moisture from seeping through. Without this protective layer, moisture can freely enter through the brick.
Cracks in Foundation
Cracks in the brick foundation walls or floor provide an easy entry point for water. Cracks develop as the foundation settles over time. Tree roots, soil shifting, and freeze/thaw cycles can also cause foundation cracks.
Inadequate Drainage
Insufficient drainage around the exterior foundation can lead to excessive moisture in the soil. This saturates the brick and provides a huge source for water seepage into the basement.
High Water Table
A high water table means a higher level of groundwater around the foundation. This produces hydrostatic pressure that can force water in through any cracks or pores in the brick floor.
By understanding these common causes, you’ll know which waterproofing solutions to focus on for your unique situation. Proper drainage, sealing cracks, adding a vapor barrier, and preventing hydrostatic pressure are all important in keeping basement floors dry.
Waterproofing Options for Brick Basement Floors
Several effective waterproofing options exist for preventing water seepage through brick basement floors. The best choice depends on your budget, the severity of moisture issues, and whether you want to redo the flooring. We’ll overview the most common techniques below.
Interior Drainage System
Interior drainage systems are the most thorough waterproofing solution. They involve digging a trench drain along the interior perimeter of basement walls. The drain is covered with gravel and a sump pump is installed to collect water and pump it away from the foundation.
A vapor barrier is laid over the floor and often a new concrete floor is poured on top. An interior system keeps the basement dry by intercepting incoming water and sending it to the sump pump before it can permeate the floor. It also relieves hydrostatic pressure on the foundation.
Exterior Waterproof Coating
Applying a waterproof cement coating to the exterior foundation walls and floors is an affordable waterproofing option. The coating fills in pores and seals cracks to prevent moisture from seeping through.
Look for polymeric or epoxy-based coatings that won’t degrade over time. This technique prevents water intrusion but doesn’t help relieve hydrostatic pressure. Perform crack repairs before application.
Injection Epoxy Sealing
With this technique, epoxy sealant is injected directly into cracks in the brick floor and walls. Epoxy bonds tenaciously to structural materials, forming a permanent watertight seal.
Use around pipe penetrations, floor-wall joints, cracks wider than 1/8″, and any faults allowing water to enter. Combine with an interior drain system for optimal results.
Subfloor Membrane
Installing a waterproofing subfloor membrane is an affordable DIY approach. Roll out a rubberized asphalt or thick plastic membrane over the existing floor. Seal seams with waterproof tape. Top with plywood and new flooring.
This doesn’t stop moisture intrusion but prevents dampness from permeating flooring materials. Subfloors are easy to install but less effective than active drainage.
Individual Brick Sealing
For minor moisture seepage through a few porous bricks, individual sealing is an option. Sealants like hydraulic cement, epoxy grout, or urethane caulk can be applied just to problem brick areas.
Caulk around pipe intrusions, floor-to-wall joints, and noticeable moisture entry points through bricks. This won’t waterproof the entire floor but can help with small damp spots.
How to Install an Interior Basement Drainage System
If significant moisture is coming up through your brick basement floor, an interior French drain system is the best way to waterproof it for the long-term. Here are the steps involved in this process:
Step 1: Mark the Drainage Trench Location
Measure about 6-12 inches away from basement walls and mark with chalk or tape where the interior drainage trench will be dug. The trench should encircle the entire interior perimeter.
Aim to dig it about 12 inches wide and 6 inches deep. The trench will be filled with gravel, a perforated drainage pipe, and a vapor barrier.
Step 2: Dig the Trench
Use a jackhammer, shovel, or backhoe to dig out the drainage trench carefully following the marked line. Wear safety goggles, gloves, boots, knee pads and a breathing mask to avoid dust inhalation.
Pile the dirt nearby to backfill the trench later. Avoid over-digging or making the trench uneven which can compromise gravel placement.
Step 3: Install Drainage Piping
Place a perforated PVC drainage pipe into the trench, about an inch above the bottom. Attach solid outlet piping that runs to a sump pump basin.
The sump pump discharges water away from the house through an exterior outlet. Fill pipe sections with couplings or use one continuous winding pipe around the perimeter.
Step 4: Backfill Gravel
Shovel drainage gravel into the trench around and over the piping. Leave about 2 inches below floor level for the vapor barrier and concrete. Use clean gravel about 3/4 inch to 1.5 inches in diameter.
Compact gravel layers every 6 inches with a tamping tool for proper drainage. The gravel carries seepage water to the drain pipe.
Step 5: Install Vapor Barrier
Roll out an 6mil polyethylene plastic sheet over the gravel, with overlapping seams taped. This vapor barrier prevents moisture from permeating back up into the basement. Secure barrier to walls with acoustical sealant.
Step 6: Pour New Concrete Floor
Pour a 2-4 inch concrete floor over the vapor barrier for a smooth, seamless finish. Use a moisture-resistant concrete mix. Cut the barrier only where floor drains will be installed. Allow the concrete to fully cure for 7-10 days before walking on it.
Step 7: Backfill Dirt & Grading
Backfill the excavated dirt into the trench over the gravel and concrete. Pack down with a tamping tool. Re-grade soil around the exterior foundation for proper slope and drainage away from the house.
With these seven steps, you’ll have a fully waterproofed brick basement floor that will remain bone dry for decades to come! Be sure to maintain your sump pump system properly.
Tips for Maintaining a Dry Brick Basement Floor
Completing basement waterproofing projects represents a major investment of money, time, and effort. To safeguard your investment and keep the space dry for the long run, be sure to follow these maintenance tips:
- Inspect the sump pump regularly to ensure proper functioning. Test monthly. Replace pumps every 3-5 years.
- Keep the sump pump basin clear of debris which can block the pump intake screen. Monitor for signs of backup.
- Check the discharge line outside your home for kinks or blockages from ice or dirt. Discharge extension piping may help.
- Pour water into floor drains regularly to maintain traps seals. Add bacteriacide tablets to prevent sewer gas smells.
- Routinely inspect the basement floor and walls for new cracks. Seal new cracks with hydraulic cement or epoxy injections before they leak.
- Monitor relative humidity with a hygrometer. Keep levels below 60% to deter mold growth. Use a dehumidifier as needed.
- Direct rainwater and downspouts at least 5 feet away from your foundation walls using downspout extensions or drains.
- Maintain grading around the exterior of your home to promote water runoff. Fill in soil erosion and low spots.
With diligent maintenance and immediate repair of any new moisture entry points, your waterproofed brick basement floor and walls should remain water-free for many decades. Don’t ignore small leaks as they will only worsen over time. Addressing seepage promptly is the key to long-term success.
Frequently Asked Questions About Waterproofing Brick Basement Floors
What causes water to come up through my brick basement floor?
The most common causes are porous bricks allowing moisture seepage, cracks or faults in the brick or foundation, inadequate drainage around the foundation, and hydrostatic pressure from a high water table. Understanding the source of the moisture is key to proper waterproofing.
Does sealing the basement walls help make the floor drier?
Yes, sealing cracks and coating the exterior foundation walls helps minimize moisture sources that could saturate a brick floor. However, additional measures like a drainage system or subfloor membrane will also be needed to keep the floor itself dry.
Can I just apply a sealer or epoxy paint to the brick floor?
Sealants help minimally but don’t offer complete waterproofing for a brick floor. They won’t stop hydrostatic pressure or allow drainage. Full waterproofing requires addressing the brick’s permeability and adding a drainage system.
Should I expect my waterproofing system to last a lifetime?
With periodic maintenance, you should expect at least 50 years from a properly installed interior drainage system. Epoxy injections may last 10-15 years before needing reapplication. Exterior coatings have a shorter lifespan and will require redoing every 5-10 years.
Can I install a basement waterproofing system myself?
Interior drainage systems require special expertise and equipment for digging, drain installation, and concrete work. Most homeowners opt to hire professional waterproofing contractors unless they have relevant experience. Simpler DIY options include subfloor membranes, epoxy wall sealing, or exterior paint coatings.
How much does it cost to waterproof a 500 sq ft brick basement?
For interior drainage, expect costs between $5,000-$12,000 depending on the age of your home, severity of leakage, and the waterproofing company used. DIY installations with a subfloor membrane cost about $1,500. Exterior epoxy wall coatings run $1,500-$3,000 installed.
Conclusion
Brick basement floors prone to moisture issues can create an unpleasant, unhealthy environment. Thankfully, by arming yourself with the right waterproofing knowledge, you can tackle problems head-on and create a clean, dry space your family can fully utilize and enjoy.
With techniques like interior and exterior drainage, vapor barriers, epoxy sealing, and dehumidification, you can control moisture seepage and keep your basement dry well into the future. Avoid ignoring early signs of dampness as addressing problems promptly is always easier than allowing longer-term water damage to occur.
Carefully evaluate the best waterproofing options for your specific situation using the guidance above. With diligent maintenance and professional repairs when plumbing leaks or foundation cracks occur, your newly waterproofed brick basement will provide many years of service as a livable, damage-free area of your home. The investment of effort pays huge dividends in added usable space, stored valuables protected from water damage, and enhanced health through the prevention of mold growth.