When thinking of waterproofing, you probably picture sealing roofs or coating exterior walls. Although these are crucial waterproofing measures, water has a sneaky way of gatecrashing inside your building through cracks, joints, or condensation.
Enter interior waterproofing.
Waterproofing from the inside creates a controlled barrier between interior spaces and unwanted moisture. This ensures that even if water seeps in from the outside or condensation forms inside the house, it will not reach your walls, floors, or foundation, where it can wreak havoc.Why interior waterproofing matters
- Structural weakening of concrete and brickwork
- Mould and mildew growth (posing related health risks)
- Damage to finishes such as paint, flooring, and cabinetry
- Decreased property value
Common causes of interior water problems
Condensation: High humidity in bathrooms, kitchens, and basements can lead to condensation buildup on walls and ceilings.
Hydrostatic pressure: When groundwater presses against your foundation, it can force water through small cracks.
Plumbing leaks: Hidden leaks behind walls or under floors can create damp patches and invite mould growth.
Poor drainage: Inefficient exterior drainage systems can cause moisture to collect along the base of your walls.
How to waterproof from the inside out
There is no one-size-fits-all approach to interior waterproofing. Different areas require distinct protection methods. Some of the most effective solutions include:
1. Sealants and coatings
Specialised waterproof coatings or membranes can be applied directly to interior walls or floors. These create a moisture barrier that prevents water from sneaking in through porous materials like concrete or plaster.
2. Interior drainage systems
In basements or low-lying rooms, an interior drainage channel or sump pump system can collect and redirect water before it rises to damaging levels.
3. Crack injections
For foundations and structural walls, polyurethane or epoxy injections can fill and seal cracks from the inside, blocking any path for water infiltration.
4. Vapour barriers and insulation
Insulation keeps heat in or out, while the thin protective layer of a vapour barrier prevents moisture from passing through walls, ceilings, or floors. Adding these partners in climate control to humid spaces helps control condensation, maintain a stable indoor environment, and prevent water damage.Top tips for keeping your interiors dry
- Inspect regularly: Look for signs of damp, flaking paint, or “Eau de Granny’s Attic” – early intervention saves money.
- Control humidity: Use dehumidifiers or ensure proper ventilation in bathrooms and kitchens.
- Maintain gutters and downpipes: Even interior dampness often starts with exterior water mismanagement.
- Fix leaks quickly: A minor plumbing leak can cause major internal damage over time.
- Use the correct paint: Moisture-resistant coatings can help protect interior finishes from humidity.
How Coastal Painting & Waterproofing can help
At Coastal Painting & Waterproofing, we understand that effective waterproofing is not just about keeping rain out. You need your property from every angle – and even during non-rainy seasons like Capetonian summers. Our team offers comprehensive waterproofing solutions, including both interior and exterior protection, tailored to the coastal climate.
