What Is Interior Waterproofing?

Interior Water-resistance is the process of managing water that has infiltrated your basement by safely diverting it away from the structure of your home. Unlike exterior waterproofing, which addresses water from the outside, interior services are for cases where the water is already inside your home.

This technique usually involves installing a drainage system in the inside perimeter of the basement that diverts water to a sump pump, which then pumps it out of the house. In some cases, interior walls are treated with a vapour barrier and sealant to control moisture and humidity.

Reasons Interior Waterproofing Still Works in 2025

• More Advanced materials: Drainage channels, membranes, and sump pumps are generally more durable and performant.
• Affordability: It is, on average, cheaper and less invasive than its exterior counterpart.
• Adaptable: It’s a great option for properties with limited exterior waterproofing access or limited space to work.
• Quick Installation: Many interior systems can be installed in a matter of days, causing minimal disruption to your life.

Warning Signs You May Need Interior Waterproofing

• Wet or musty smell in your basement
• Brown stains or discoloration on walls or flooring
• Visible sign of mould or mildew
• Peeling or bubbling paint or drywall
• Cracks in your foundation wall or flooring
• Excessive water pooling in your basement after a heavy rain or snow melt

How Interior Waterproofing Works

1. Digging a Trench around the Perimeter Floor: A slight trench is dug around the perimeter of the basement’s floor.
2. Drainage System Installation: A perforated drain pipe or channel is placed in the trench.
3. Sump Pump Connection: The drainage system is connected to a sump pump to remove water.
4. Gravel & Concrete Restoration: The trench is filled with gravel and then re-cemented for a finished look.
5. Optional Wall Treatments: If desired, vapour barriers or sealants can be applied to the walls for additional moisture containment.

Should You Consider Investing in Interior Waterproofing?

Yes, certainly! Beyond preventing flooding or dampness, this system can protect the structure of the house, protect your belongings and valuables, assist in maintaining indoor air quality, help the resale value of your property, and give you peace of mind during inclement weather.

The Importance of Professional Installation

When selecting a contractor, ensure they provide detailed inspections and transparent proposals, quality materials, insurance, licensing, and experience in your area, and warranty coverage for work done to your property, including labour and materials.