Who carries out the structural integrity test?

The main contractor, before we start. The tank is filled to at least two-thirds of its height and the outside is checked for leaks.

What happens if the tank leaks in that test?

Leaking areas are injected with CHEMFOAM PU 6261 and defective concrete is patched with CHEMGROUT 215. The repairs are made on the shell, before the lining goes on.

How many coats of BRUSHCRETE FX?

Three, on the base and the walls, with three to four hours of drying between coats.

Is the concrete itself waterproofed?

Yes. MIXKOTE MIM is dosed into the concrete at 1% of the cement content, and the construction joints carry a CENTRESEAL 250 waterstop.

How long is the finished tank tested for?

48 hours. A water-retaining structure is held full for two days and checked before handover.

All systems, by building zone

RC Water Tank Waterproofing.

Suction tanks, elevated tanks and reservoirs. The water is on the inside and it is drinking water, so the coating has to hold under a permanent head and stay inert. This page sets out the layers, the order of work and the tests a tank goes through before handover.

3Coats of BRUSHCRETE FX on the base and the walls.

1%MIXKOTE MIM by weight of the cement, dosed into the concrete at the batching plant.

250 mmWidth of the CENTRESEAL 250 waterstop cast into the construction joints.

48Hours the tank is held full for the pond test before handover.

The build-up.

Six steps, from the concrete shell to the lining.

From the structure in

Concrete dosed with MIXKOTE MIMCrystallisation admixture, so the concrete itself resists water. It is added at 1% of the cement content when the concrete is batched.
CENTRESEAL 250 PVC waterstopAt construction joints, cast centrally in the concrete.
Structural integrity testBy the main contractor, before we start. The tank is filled to at least two-thirds of its height and the outside is checked for leaks.
Crack repair with CHEMFOAM PU 6261Injected structural repair where needed. Honeycombs are patched with CHEMGROUT 215.
Protective screed, 25 mmCement and sand (1:4).
BRUSHCRETE FX, three coatsFlexible two-component polymer-modified cementitious membrane, on the base and the walls.

The water tank build-up drawn exploded: the dosed concrete shell, waterstops at the kickers, the structural integrity test, a crack repair through the wall, then the protective screed and BRUSHCRETE linings lifted out

How the job runs.

Watertight concrete and waterstopsMIXKOTE MIM goes into the concrete at the batching plant, and CENTRESEAL 250 is cast into the construction joints.
Structural integrity testThe main contractor fills the tank to at least two-thirds of its height, and the outside is watched for leaks.
Repairs on the shellLeaking areas are injected with CHEMFOAM PU 6261. Honeycombs and defective concrete are patched with CHEMGROUT 215 non-shrink grout.
Clean surface, then filletsThe surface is cleared of mortar, laitance, oil and protruding steel. A 25 mm by 25 mm mortar fillet goes into every corner and sharp edge.
Protective screed25 mm of cement and sand (1:4).
Three coats of BRUSHCRETE FXOn the base and the walls. Each coat dries for three to four hours before the next.
Then we pond testThe tank is filled and held for 48 hours, and checked before handover.

Corners, joints and repairs.

Corners
A 25 mm by 25 mm mortar fillet at every corner and sharp edge.
Construction joints
A CENTRESEAL 250 PVC waterstop, cast into the joint.
Honeycombs
Patched with CHEMGROUT 215 before any coating.
Leaks found in the test
Injected with CHEMFOAM PU 6261, on the shell, before the lining goes on.

Materials.

MIXKOTE MIM
Crystallisation admixture in powder form, added to the concrete at the batching plant.
CENTRESEAL 250
Centrally placed PVC waterstop.
CHEMFOAM PU 6261
Polyurethane injection grout. It reacts with water to form a flexible foam that closes the leak.
CHEMGROUT 215
Cementitious non-shrink grout for honeycombs and patching.
BRUSHCRETE FX
Two-part, polymer-modified, flexible cementitious waterproofing coating.

These products are made by CHEMIND. Where a project specifies another manufacturer's system, we apply that instead.

Water tanks in our register.

Three entries in our job register name a water tank in the title, from 1989 to 2017:

1989
Underground water tanks and sump, Jalan Conlay, Kuala Lumpur
2007
Leak repairs to a swimming pool, water tanks and lift pits
2017
Rectification of two water tanks, Kulim

Most entries record the job as a waterproofing package without naming the zone. See the full register.

Questions we are asked.

Who carries out the structural integrity test?: The main contractor, before we start. The tank is filled to at least two-thirds of its height and the outside is checked for leaks.
What happens if the tank leaks in that test?: Leaking areas are injected with CHEMFOAM PU 6261 and defective concrete is patched with CHEMGROUT 215. The repairs are made on the shell, before the lining goes on.
How many coats of BRUSHCRETE FX?: Three, on the base and the walls, with three to four hours of drying between coats.
Is the concrete itself waterproofed?: Yes. MIXKOTE MIM is dosed into the concrete at 1% of the cement content, and the construction joints carry a CENTRESEAL 250 waterstop.
How long is the finished tank tested for?: 48 hours. A water-retaining structure is held full for two days and checked before handover.

Talk to us about a tank.

Phone and WhatsApp016-332 7534

Emailinfo@hydrocon.com.my