Certified Waterproofing Inspector (CWI)
CWI - CERTIFIED WATERPROOFING INSPECTOR | LATEST
EXAM QUESTIONS AND SOLUTIONS - VERIFIED ANSWERS
2026/2027
CERTIFIED WATERPROOFING INSPECTOR (CWI)
1. Which three conditions must all exist at the same time for water to
leak through a building enclosure?
A. Wind, sunlight, and a porous substrate
B. Water present, an opening, and a force to move the water through the
opening
C. High humidity, negative pressure, and an exposed sealant joint
D. Water present, low temperature, and a vapor retarder
B. Water present, an opening, and a force to move the water through
the opening
A leak needs a water source, a path, and a driving force; removing any
one of the three stops the leak.
Page 1 of 60
, Certified Waterproofing Inspector (CWI)
2. Hydrostatic pressure on a below-grade wall is caused primarily by:
A. Wind pressure transferred through the soil
B. The weight of a column of groundwater acting against the wall
C. Capillary rise within the concrete pores
D. Vapor drive from interior heating
B. The weight of a column of groundwater acting against the wall
Hydrostatic pressure increases with depth of saturated soil and pushes
water against the structure.
3. Each foot of water head below the water table produces
approximately what hydrostatic pressure?
A. About 144 pounds per square foot
B. About 14.7 pounds per square foot
C. About 62.4 pounds per square foot
D. About 6.24 pounds per square foot
C. About 62.4 pounds per square foot
Water weighs about 62.4 lb per cubic foot, so each foot of head adds
roughly 62.4 psf (0.433 psi).
4. The movement of water upward through fine pores in concrete or
soil against gravity is called:
A. Capillary action
B. Hydrostatic uplift
C. Osmotic blistering
D. Gravity drainage
A. Capillary action
Small pores pull water through surface tension, which is why capillary
breaks are placed under slabs.
Page 2 of 60
, Certified Waterproofing Inspector (CWI)
5. Which statement best describes the difference between
waterproofing and dampproofing?
A. Dampproofing resists hydrostatic pressure, while waterproofing only
resists vapor
B. Waterproofing resists water under hydrostatic pressure, while
dampproofing only resists moisture without pressure
C. They are interchangeable terms under building codes
D. Waterproofing is applied only to roofs and dampproofing only to walls
B. Waterproofing resists water under hydrostatic pressure, while
dampproofing only resists moisture without pressure
Dampproofing is intended for soil moisture with no head of water;
waterproofing must hold back water under pressure.
6. A 'positive-side' waterproofing system is installed:
A. On the face of the structure that is in direct contact with the water
source
B. Between two layers of interior drywall
C. Inside the concrete during the pour only
D. On the interior face opposite the water source
A. On the face of the structure that is in direct contact with the water
source
Positive-side systems keep water out of the substrate by sitting on the
wet side of the wall or slab.
7. Which is a main advantage of positive-side waterproofing over
negative-side waterproofing?
A. It is unaffected by substrate cracking
B. It never requires protection board
C. It can always be installed after backfill without excavation
D. It protects the structural concrete and reinforcing steel from water and
dissolved chemicals
D. It protects the structural concrete and reinforcing steel from
water and dissolved chemicals
Keeping water out of the concrete limits corrosion of reinforcement and
freeze-thaw or chemical attack.
Page 3 of 60
, Certified Waterproofing Inspector (CWI)
8. Negative-side waterproofing is most often selected when:
A. New construction allows full access to the exterior face
B. The wall is a roof parapet
C. The membrane must bridge large dynamic cracks
D. The positive side is not accessible, such as an existing basement with
backfill in place
D. The positive side is not accessible, such as an existing basement
with backfill in place
Negative-side systems are applied from the interior and are common in
remedial work where excavation is impractical.
9. Blindside waterproofing refers to a membrane that is:
A. Applied to the interior face after construction
B. Installed only beneath roofing
C. Hidden behind interior finishes
D. Installed against lagging or shoring before the foundation wall is cast
against it
D. Installed against lagging or shoring before the foundation wall is
cast against it
In blindside work the membrane is fixed to the support of excavation and
the concrete is placed directly against it.
10. Which force can drive water through a sealant joint even when no
hydrostatic head exists?
A. Magnetic attraction
B. Thermal mass
C. Air pressure difference across the wall
D. Electrical potential
C. Air pressure difference across the wall
Wind creates a pressure difference that pushes water inward through any
opening in the joint.
Page 4 of 60
CWI - CERTIFIED WATERPROOFING INSPECTOR | LATEST
EXAM QUESTIONS AND SOLUTIONS - VERIFIED ANSWERS
2026/2027
CERTIFIED WATERPROOFING INSPECTOR (CWI)
1. Which three conditions must all exist at the same time for water to
leak through a building enclosure?
A. Wind, sunlight, and a porous substrate
B. Water present, an opening, and a force to move the water through the
opening
C. High humidity, negative pressure, and an exposed sealant joint
D. Water present, low temperature, and a vapor retarder
B. Water present, an opening, and a force to move the water through
the opening
A leak needs a water source, a path, and a driving force; removing any
one of the three stops the leak.
Page 1 of 60
, Certified Waterproofing Inspector (CWI)
2. Hydrostatic pressure on a below-grade wall is caused primarily by:
A. Wind pressure transferred through the soil
B. The weight of a column of groundwater acting against the wall
C. Capillary rise within the concrete pores
D. Vapor drive from interior heating
B. The weight of a column of groundwater acting against the wall
Hydrostatic pressure increases with depth of saturated soil and pushes
water against the structure.
3. Each foot of water head below the water table produces
approximately what hydrostatic pressure?
A. About 144 pounds per square foot
B. About 14.7 pounds per square foot
C. About 62.4 pounds per square foot
D. About 6.24 pounds per square foot
C. About 62.4 pounds per square foot
Water weighs about 62.4 lb per cubic foot, so each foot of head adds
roughly 62.4 psf (0.433 psi).
4. The movement of water upward through fine pores in concrete or
soil against gravity is called:
A. Capillary action
B. Hydrostatic uplift
C. Osmotic blistering
D. Gravity drainage
A. Capillary action
Small pores pull water through surface tension, which is why capillary
breaks are placed under slabs.
Page 2 of 60
, Certified Waterproofing Inspector (CWI)
5. Which statement best describes the difference between
waterproofing and dampproofing?
A. Dampproofing resists hydrostatic pressure, while waterproofing only
resists vapor
B. Waterproofing resists water under hydrostatic pressure, while
dampproofing only resists moisture without pressure
C. They are interchangeable terms under building codes
D. Waterproofing is applied only to roofs and dampproofing only to walls
B. Waterproofing resists water under hydrostatic pressure, while
dampproofing only resists moisture without pressure
Dampproofing is intended for soil moisture with no head of water;
waterproofing must hold back water under pressure.
6. A 'positive-side' waterproofing system is installed:
A. On the face of the structure that is in direct contact with the water
source
B. Between two layers of interior drywall
C. Inside the concrete during the pour only
D. On the interior face opposite the water source
A. On the face of the structure that is in direct contact with the water
source
Positive-side systems keep water out of the substrate by sitting on the
wet side of the wall or slab.
7. Which is a main advantage of positive-side waterproofing over
negative-side waterproofing?
A. It is unaffected by substrate cracking
B. It never requires protection board
C. It can always be installed after backfill without excavation
D. It protects the structural concrete and reinforcing steel from water and
dissolved chemicals
D. It protects the structural concrete and reinforcing steel from
water and dissolved chemicals
Keeping water out of the concrete limits corrosion of reinforcement and
freeze-thaw or chemical attack.
Page 3 of 60
, Certified Waterproofing Inspector (CWI)
8. Negative-side waterproofing is most often selected when:
A. New construction allows full access to the exterior face
B. The wall is a roof parapet
C. The membrane must bridge large dynamic cracks
D. The positive side is not accessible, such as an existing basement with
backfill in place
D. The positive side is not accessible, such as an existing basement
with backfill in place
Negative-side systems are applied from the interior and are common in
remedial work where excavation is impractical.
9. Blindside waterproofing refers to a membrane that is:
A. Applied to the interior face after construction
B. Installed only beneath roofing
C. Hidden behind interior finishes
D. Installed against lagging or shoring before the foundation wall is cast
against it
D. Installed against lagging or shoring before the foundation wall is
cast against it
In blindside work the membrane is fixed to the support of excavation and
the concrete is placed directly against it.
10. Which force can drive water through a sealant joint even when no
hydrostatic head exists?
A. Magnetic attraction
B. Thermal mass
C. Air pressure difference across the wall
D. Electrical potential
C. Air pressure difference across the wall
Wind creates a pressure difference that pushes water inward through any
opening in the joint.
Page 4 of 60
