Well Waterproofing
December 7, 2022
Wood Plank Effect
January 5, 2023How to Choose Waterproofing Materials for Walls and Foundations?
Selecting the right construction and waterproofing materials is not a simple task. The best approach is to consult a specialist, who can help assess which products will be most effective while considering financial constraints.
While price often correlates with quality, the most expensive solution is not always the most suitable.
Factors Influencing the Selection of Waterproofing Materials
Choosing waterproofing materials is more complex than simply following what a neighbor or family member recommends. Incorrectly selected materials may be ineffective, leading to costly repairs and replacement of the insulation.
Several factors must be considered to ensure proper waterproofing:
- Building type and usage – Different materials are required for indoor and outdoor applications, as exposure to UV radiation can degrade certain products.
- Application location – The selection depends on whether the waterproofing is applied to walls, foundations, or other structural elements.
- Climatic and groundwater conditions – Soil surveys provide essential information for choosing the right materials.
- Chemical exposure – Some soils and water contain aggressive compounds that may require additional protection.
- Sanitary requirements – Proper waterproofing ensures hygienic conditions and long-term cost savings.
Selecting Waterproofing Based on Risk Level
Water can threaten a building in multiple ways, including rain, snow, fog, and groundwater. Groundwater levels fluctuate throughout the year, making it critical to select a durable waterproofing system.
If uncertain, waterproofing against pressurized water is generally a safer choice than moisture-resistant insulation, as it provides higher protection levels.
Types and Uses of Waterproofing
In previous articles, we described different classifications of waterproofing materials, such as:
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Installation method:
- Vertical waterproofing (external walls, foundation walls).
- Horizontal waterproofing (foundations, ceilings, and roofs).
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Type of threat:
- Moisture-resistant (protection against humidity).
- Waterproof (protection against hydrostatic pressure).
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Waterproofing intensity:
- Light – Protection against moisture penetration.
- Medium – Protection against direct, capillary, or seeping water.
- Heavy – Protection against pressurized water.
This article will focus on classifying waterproofing materials based on the materials they are made of:
Mineral Waterproofing
Mineral-based liquid membranes are ready-to-use, single-component products. They contain synthetic resins, which form a highly flexible waterproofing layer upon contact with moisture.
Features:
- High flexibility
- Easy application
- Crack-bridging capabilities
- Strong adhesion to concrete, cement-based mortars, and brick walls
Applications:
- Indoor use
- Moisture protection for walls and floors in bathrooms and shower enclosures, before installing ceramic tile and natural stone cladding
- Moisture protection for walls, floors, and countertops in kitchens, before applying ceramic or natural stone finishes
Single- or Two-Component Slurries
Single- or two-component slurries are flexible, cement-based coatings. Depending on the thickness and number of applied layers, they provide both waterproofing and moisture protection.
Features:
- Strong adhesion (even on damp surfaces)
- Elasticity
- Quick load-bearing capacity
- Crack-bridging
- Resistance to weak inorganic acids, alkaline solutions, municipal sewage, and UV radiation (not all products)
Applications:
- For mineral substrates (concrete, cement and anhydrite screeds, gypsum plasters, gypsum boards, ceramics) and asphalt substrates
- For moisture and waterproofing
- Positive and negative waterproofing
- On deformable and non-deformable surfaces as waterproofing for structures from the side opposite to water pressure
- Protection against moisture and groundwater (including pressurized water) in earth-covered structures, basements, underground garages, swimming pools, and potable water tanks
Crystallizing Coatings
Crystallizing coatings are materials used to seal concrete from within its structure. These products are most commonly added to concrete as admixtures, where they seal or bridge gaps through a chemical reaction, forming a crystalline structure.
Features:
- High adhesion
- Waterproofing capability
- Unlimited sealing durability
- Water exposure reactivates the sealing process
- Effective for underground sealing, including internal applications
- Vapor-permeable
- Compatible with mineral substrates
Applications:
- Used for sealing water reservoirs, wastewater treatment plants, and pumping stations, as well as septic tanks, swimming pools, underground building structures (basements, bunkers, underground garages), tunnels, inspection chambers, and wet rooms (e.g., steam baths)
- Suitable for moderately aggressive environments
- Used in residential, industrial, and public utility construction
- Applicable both from the inside and outside of structures
- Waterproofing for concrete and reinforced concrete structures
- Can be applied during construction or for existing structures from the inside
- Used for sealing foundation slabs, footings, monolithic walls, and reinforced floors
Bituminous Waterproofing
Thin-layer bituminous coatings are emulsions based on bitumen-latex compounds. These flexible products create a seamless, uniform waterproofing layer.
Features:
- Flexible
- Seamless application
- Adaptable to irregular surfaces
- Easy to apply
- May contain adhesion enhancers for better bonding
- Often suitable for slightly damp substrates
Applications:
- Vertical and horizontal moisture-proofing insulation
- Primer for thick-layer bituminous waterproofing (KMB coatings)
Thick-Layer Polymer-Modified Bituminous Coatings (KMB)
Polymer-modified bituminous coatings (KMB) are one- or multi-component, odorless, and solvent-free products. They provide high protection against rainwater and groundwater and are used for heavy-duty waterproofing.
Features:
- Odorless
- Solvent-free
- Single-component coatings become water-resistant after complete drying
- Two-component coatings cure without air exposure and/or in the presence of water
- Elastic properties allow crack-bridging up to 5 mm
Applications:
- Waterproofing of structures in contact with soil (e.g., foundations, basement walls)
- Vapor barrier layer in balcony, terrace, flat roof, and green roof waterproofing systems
Bituminous Sheet Waterproofing
Bituminous sheet waterproofing includes self-adhesive bituminous membranes and roofing felt. Self-adhesive roofing felt can serve as the final waterproofing layer. The membrane consists of self-adhesive bitumen laminated with an HDPE film on the top, while self-adhesive roofing felt is reinforced with a fiberglass mesh.
Features:
- Easy and watertight joint sealing
- Fast application
- Immediate waterproofing
- Not vapor-permeable
Applications:
- Vertical and horizontal waterproofing
- Vapor barrier layer in balcony, terrace, flat roof, and green roof waterproofing systems
Plastic-Based Waterproofing
This is a diverse group of materials that, due to advanced technology, outperform traditional waterproofing solutions.
Liquid Plastic Membranes
Features:
- High water resistance
- Bridges cracks up to 1 mm
- Flexible and stretchable
- Seamless and joint-free
- Fully cured after 24 hours
- Good adhesion to mineral substrates
- Vapor-permeable
- Not resistant to acids, alkalis, oils, and solvents
Applications:
- Final waterproofing layer with additional finishing options (anti-slip coatings, decorative chips, or other finishes depending on the manufacturer)
- Can be applied to concrete substrates, cement screeds, fully jointed brick walls, cement and lime-cement plasters, gypsum plasters, gypsum board, and wood-based panels
Sheet Waterproofing with Plastics
Features:
- Durable
- Easy to install
- Varied types, including flat sheets, membranes, and dimpled sheets made of polyethylene (PE) or polyvinyl chloride (PVC)
Applications:
- Moisture and vapor protection under roof coverings
- Moisture and waterproofing insulation for foundations
