Industrial Waterproofing and Fluid-Applied Membrane Systems

Article 04 of 24

Defining the Structure, Exposure, and Service Conditions

Waterproofing selection should begin with a written description of what the structure, membrane, details, and protection system will experience throughout construction and service.

Learning Objectives

After completing this article, the reader should be able to:

• Develop a practical service profile for an industrial or commercial waterproofing project.
• Identify structural, water, environmental, chemical, traffic, and construction exposures.
• Separate temporary construction conditions from long-term service conditions.
• Recognize when the project requires protection, drainage, reinforcement, or an integral wearing surface.
• Document unknown conditions that must be resolved before estimating or installation.

Select the System From the Service Conditions

A waterproofing product should not be selected simply because it has been used successfully on another project. Two concrete structures may look similar while experiencing entirely different water pressure, movement, temperature, chemicals, traffic, construction sequencing, and repair limitations.

The contractor needs a service profile that describes what the waterproofing must resist, where it will be installed, how it will be protected, and how its performance will be verified.

Without that profile, product selection becomes an assumption. Assumptions made during estimating frequently become change orders, delays, warranty disputes, or failures after the membrane has been concealed.

1. Identify the Structure

Begin by identifying the structure and the waterproofed area in specific terms:

• Foundation wall or retaining wall
• Structural slab or slab-on-ground
• Elevated deck, podium, plaza, balcony, or terrace
• Parking structure or vehicle area
• Pit, trench, sump, vault, or equipment foundation
• Tunnel, utility structure, or underground passage
• Mechanical room, washdown area, or process space
• Expansion, rehabilitation, or repair of an existing waterproofed structure

Record dimensions, elevations, slopes, changes in plane, wall thicknesses, construction joints, penetrations, drains, terminations, and connections to adjoining waterproofing systems.

2. Define the Substrate

The substrate affects adhesion, preparation, detailing, moisture tolerance, material consumption, and the likelihood of future movement.

• Cast-in-place concrete
• Precast concrete
• Concrete masonry
• Shotcrete
• Steel, stainless steel, or other embedded metals
• Repair mortars, grout, sealants, and previous patches
• Existing coatings, membranes, mastics, or adhesives
• Transitions between different substrate materials

New concrete, aged concrete, repaired concrete, and previously waterproofed concrete should not be treated as equivalent surfaces. Strength, moisture, porosity, contamination, cracking, profile, and previous treatments must be evaluated.

3. Define the Water Exposure

Identify the water source, frequency, duration, depth, pressure, direction, and drainage path.

4. Determine the Waterproofing Direction

Identify whether the system will be positive-side, blind-side, or negative-side waterproofing. Record where water pressure will act and whether it will push the membrane toward or away from its supporting surface.

Do not accept a generic statement that a material is suitable for “below-grade waterproofing.” Confirm that the manufacturer approves the exact installation direction, substrate, pressure, exposure, and construction sequence.

5. Define Structural Movement

Waterproofing must accommodate anticipated movement without tearing, losing adhesion, or opening at details.

• Concrete drying shrinkage
• Thermal expansion and contraction
• Structural deflection
• Settlement or differential movement
• Vibration from equipment or traffic
• Movement at construction and control joints
• Movement at expansion and isolation joints
• Differential movement between dissimilar materials

A membrane’s elongation percentage alone does not define its ability to bridge a particular moving crack or joint. Movement width, frequency, temperature, reinforcement, membrane thickness, adhesion, and detail geometry must also be considered.

6. Define Temperature and Weather Exposure

Record both installation temperatures and long-term service temperatures.

• Minimum and maximum ambient temperature
• Minimum and maximum substrate temperature
• Daily temperature swings
• Freeze-thaw exposure
• Direct sunlight and ultraviolet exposure
• Rain, condensation, frost, or dew during installation
• Hot-water washdown or process-temperature exposure
• Heat created by equipment, piping, or operating processes

Some membranes are designed to remain exposed, while others must be covered. A buried membrane, exposed traffic-bearing membrane, and membrane beneath a wearing course require different properties and protection.

7. Identify Chemical and Biological Exposure

Waterproofing may contact more than clean water. Identify all known or reasonably anticipated exposures:

• Fuels, oils, lubricants, and hydraulic fluids
• Cleaning chemicals and disinfectants
• Acids, alkalis, salts, and process chemicals
• Fertilizers, deicing salts, and contaminated groundwater
• Construction chemicals, sealants, adhesives, and curing compounds
• Roots, microorganisms, or biological growth
• Chemicals that may migrate from protection boards, insulation, drainage composites, or adjoining materials

Request written chemical-resistance guidance from the manufacturer when exposure is uncertain. General statements such as “chemical resistant” are not adequate for a specific chemical, concentration, temperature, contact duration, or mixture.

8. Determine Traffic, Wear, and Physical Abuse

Identify whether the membrane will remain exposed or be covered by a separate protective layer.

• Pedestrian traffic
• Passenger vehicles, trucks, forklifts, or maintenance equipment
• Turning, braking, acceleration, and concentrated wheel loads
• Dropped tools, equipment, or construction materials
• Backfill placement and compaction
• Reinforcing-steel placement and concrete construction
• Cleaning, scraping, abrasion, or mechanical maintenance
• Future installation of anchors, piping, curbs, or equipment

A buried wall membrane may require protection board and drainage media. A plaza membrane may require a separate wearing course. An exposed parking-deck system may require an integral traffic-bearing surface designed for the specified vehicles and movement.

9. Evaluate Drainage and Water Management

Waterproofing resists water entry. Drainage reduces the amount of water and pressure acting on the waterproofing. The two functions support each other but should not be confused.

Review:

• Surface slope and drainage direction
• Foundation drains and discharge locations
• Drainage composites and filter fabrics
• Plaza, deck, trench, and area drains
• Scuppers, overflows, sumps, and pumps
• Potential drain blockage or maintenance limitations
• Backfill permeability and compacted-soil conditions
• Emergency conditions if the drainage system stops functioning

10. Define Installation Access and Construction Sequence

A suitable membrane cannot perform if the crew cannot safely prepare, detail, apply, inspect, and protect it.

• Is there enough clearance for preparation and application equipment?
• Can the crew see and reach every termination and penetration?
• Will scaffolding, lifts, ventilation, lighting, or confined-space controls be required?
• Can groundwater or rain reach the work during application or cure?
• Which trades work before and after the waterproofing contractor?
• When will drains, sleeves, embeds, curbs, and equipment bases be installed?
• How long will the membrane remain exposed before protection or covering?
• Who controls access after the membrane has been accepted?

11. Define Inspection, Testing, and Acceptance

Determine how the finished installation will be accepted before work begins.

• Substrate inspection and acceptance
• Mockup or test area
• Adhesion testing
• Wet-film and dry-film thickness measurements
• Coverage and material reconciliation
• Visual inspection of reinforcement and details
• Holiday or electronic leak-detection testing
• Flood testing when applicable and approved
• Repair inspection and retesting
• Written acceptance before covering or backfilling

12. Consider Repairability and Maintenance

Some membranes remain accessible. Others are permanently buried behind soil, concrete, insulation, pavers, landscaping, equipment, or wearing surfaces. Repair costs can greatly exceed the original waterproofing cost when overburden must be removed.

The service profile should address:

• Whether the membrane can be inspected after completion
• Whether leaks can be electronically located
• Whether the system permits localized repair
• Whether future tie-ins can be made
• Who maintains drains, joints, sealants, and exposed traffic surfaces
• What access and documentation future repair contractors will need

Project Service Profile

Practical Conclusion

A membrane cannot be selected correctly from the structure’s name alone. “Foundation wall,” “parking deck,” or “equipment pit” does not describe the complete exposure.

The professional contractor develops a written service profile covering the structure, substrate, water, pressure, movement, environment, chemicals, traffic, construction sequence, protection, drainage, testing, and future repair. That profile becomes the basis for system selection, estimating, work planning, and written clarification.

Technical References

Verify the current edition and project requirements before using a standard for system selection or acceptance.

• ASTM C1471/C1471M — Standard Guide for the Use of High Solids Content Cold Liquid-Applied Elastomeric Waterproofing Membrane on Vertical Surfaces.
• ASTM D7832/D7832M — Standard Guide for Performance Attributes of Waterproofing Membranes Applied to Below-Grade Walls and Vertical Surfaces Enclosing Interior Spaces.
• ASTM C957/C957M — Standard Specification for High-Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane with Integral Wearing Surface.
• ASTM C1127/C1127M — Standard Guide for Use of High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane with an Integral Wearing Surface.
• ASTM D7492/D7492M — Standard Guide for Use of Drainage System Media with Waterproofing Systems.
• ASTM D6506/D6506M — Standard Specification for Asphalt-Based Protection Board for Below-Grade Waterproofing.
• ASTM D5385/D5385M — Standard Test Method for Hydrostatic Pressure Resistance of Waterproofing Membranes.

Professional responsibility: Do not select or substitute a waterproofing system until the service conditions have been defined and compared with the current project specifications, approved details, manufacturer technical data, and written limitations. Submit unresolved conditions for clarification before pricing or installation.

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