Waterproofing wet areas like bathrooms, roofs, and balconies:
It is essential
in both new construction and repair work. If not done correctly, it can cause
water leaks, leading to expensive repairs and possible structural damage to the
building.
Refer ASTM
D5957-98: Standard Guide for Flood Testing Horizontal Waterproofing
Installations.
Before starting
flood testing, the waterproofing membrane or any other approved material must
be inspected to ensure it is fully cured and free of voids, pinholes, or
defects. If any issues are found, they must be repaired before proceeding.
For testing the
water-tightness of waterproofing installations applied to horizontal surfaces
having a slope of no greater than 20 mm/Mtr.
The recommended drying times should
be followed again until the repaired areas have fully cured. All drains in the
test area must be properly plugged with suitable plugs. The space around the
plug and drain should be filled with water to check for any leaks before
carrying out the full flood test.
Constant
monitoring is required during the flood test. Conditions under the test area
should be checked and recorded before the test starts and then every four hours
until the test is complete. The test area should be flooded with potable water,
with a minimum depth of 25 mm and a maximum depth of 100 mm at the lowest
point. The average water depth should not exceed 65 mm. When adding water,
ensure it is applied at a pressure that won't damage the membrane or affect
lapped edges. Since leaks might happen, it's important to have a contingency
plan in place to manage any water.
Flood testing
should be conducted for a minimum of 24 hours, starting once the water reaches
the recommended test depth. The membrane should not be flood-tested
continuously for more than 72 hours.
Flood Test Failure: If any
leakage is detected during the test, immediately drain the water and locate the
source of the leak. The affected area should be repaired. If the exact location
of the leak cannot be found, the entire area must be re-waterproofed.
For swimming pool, fountain and
water bodies:
Flood testing
for swimming pools, fountains, and other water features follows a process
similar to shower pan testing, but with key differences due to the scale and
complexity involved.
Key
Differences:
- Scale: The volume of water in a swimming
pool or large water feature is significantly higher than in a shower pan.
For example, while a typical 900 mm x 1200 mm shower pan holds about 60-90
liters of water, a 6 m x 12 m swimming pool with an average depth of 1.8 m
holds around 130 m³ of water, weighing over 130,000 kg.
- Penetrations: Pools and water features
generally have more penetrations (e.g., plumbing, lighting, drains) that
pass through the walls, each of which needs special attention. These
penetrations must be properly treated to maintain the overall
waterproofing system’s integrity, and the materials used for sealing must
be compatible with the primary waterproofing membrane.
- Testing Duration: The flood testing process
for pools or large water features typically lasts 24–72 hours but can take
longer due to the volume of water and the time required to fill and
stabilize the water level.
Each of these
factors makes pool and water feature flood testing more complex and requires
careful planning to ensure proper waterproofing.
During the
first day of flood testing, constant monitoring is required, followed by daily
checks thereafter. Conditions under the test area should be recorded before the
test begins and at four-hour intervals throughout the test. However, this may
not be feasible for in-ground concrete pools.
Flood
Testing Procedure:
- Fill the pool, fountain, or vessel at a rate of 25
mm per hour, up to a depth of 50 mm to 100 mm.
- Keep the water at this depth for 24–72 hours to
check for leaks in drains, returns, or other penetrations. It's advisable
to perform the test in stages, isolating specific components (e.g.,
drains, pipes) at different water levels to easily identify leaks and
address repairs.
Environmental
Loss Monitoring:
- To accurately measure water loss due to factors
like evaporation or wind, place a watertight, flat-bottom, vertical-sided
vessel (test vessel) in a nearby area that experiences the same
environmental conditions Or in the pool on the steps itself. This vessel
should have water at the same depth as the test area.
- At predetermined intervals, measure water levels in
both the test area and the test vessel. If the water loss in the test area
exceeds the water loss in the vessel, it indicates probable leakage in the
membrane or penetrations.
Leakage
Protocol:
- If leakage is detected, drain the pool, allow the membrane to dry fully, and then carry out necessary repairs before retesting.
