Water tank, balance tank and pond waterproofing
Tanks and ponds hold water all the time, so a small crack soon becomes a steady loss. Pebble Pools waterproofs concrete water tanks, balance and surge tanks, ponds and water features in Phuket and across Thailand.
Send photos → discuss the work → site assessment if needed → quotation
Upgrades & repairs for hotels and villas · Waterproofing
What we waterproof
Tanks and ponds are close to our pool work. They use the same concrete, need the same care at joints and fittings, and have to hold water day after day. Pond and tank waterproofing without tiling is possible on a concrete base; a pond built on a flexible liner cannot be waterproofed by us.
- Concrete water storage tanks, above or below ground
- Pool balance tanks and surge tanks, including tanks with corroded or cracked walls
- Concrete-based koi ponds, reflecting ponds and garden ponds
- Waterfalls of any kind — natural stone, lit waterfalls, water curtains and cascades — along with channels and other water features
Systems we use
We choose the type of system for each concrete structure after inspection.
- Rigid cementitious waterproofing for concrete tanks and shells where the base does not move
- Coatings for concrete tanks and ponds that hold up in the open sun without a protective covering
- For concrete ponds, coatings that can also carry colour, so the waterproofing becomes the finished surface without tiling
- Negative-side waterproofing for tanks below ground where groundwater presses in from outside
Balance and surge tank repairs
A leaking balance tank can drain a pool without anyone seeing the water go. We inspect the tank walls, floor, corners and pipe entries. Leak finding includes pipework pressure tests and pump on/off level checks, though we cannot promise to find every leak. Corroded walls can be replastered and reinforced at the corners before the waterproofing goes on. If the old tank is too damaged to repair directly, a tank-in-tank rebuild may suit: a new tank formed inside the old one. In difficult cases, a tank-in-tank approach can also be used for a pool. Engineering decisions are made with you and your engineer — or, if you don't have one, with our partner engineer.
Planning the work
Tanks and ponds must be emptied and dried before waterproofing. Draining a below-ground tank or pond in the wet season or where groundwater is high needs care so outside water pressure does not damage the empty structure. Hidden problems may only appear once the tank or pond is emptied and work starts, especially when its history is unknown, so repairs, testing and restarting can go in stages. For ponds with fish and plants, we agree with you how they are moved and kept during the work. For storage tanks, we agree how the property's water supply is managed in the meantime. Incoming water filtration can be added at the same time; see our page on incoming water filtration.
Related pages: Pool leak repair & waterproofing and Basement, pit and pump room waterproofing.
What to send for a first discussion
For a first discussion and a quotation, send us:
- Photos of the tank, pond or water feature, inside and out where possible
- The property location in Phuket or elsewhere in Thailand
- The approximate size and depth, whether it is above or below ground, and confirmation that the base is concrete
- How much water it loses, and any cracks, damp or past repairs you have noticed
Where we have done this
CompletedPrivate Villa, Bang Tao — Black Granite
Pool renovation, new pool lights and surge tank waterproofing
The renovated pool, filled
The surge tank had been leaking badly and its walls were corroded. It was replastered, reinforced with mesh at the corners and waterproofed.
CompletedPrivate Villa, Rawai — Polar White
Leak found and fixed at the overflow; tile and render stripped, new steps, drain channel, top-up, salt chlorinator and pump, new finish
The renewed pool and the villa
As part of a pool renovation after an overflow leak, the tanks were waterproofed and the automatic top-up and drain channel were rebuilt.
CompletedPrivate Villa, Thepkrassatri — White Halo
Pool extension with a shallow ledge and air massage, a jacuzzi and seating, the old steps and seats removed and new compact steps built, a larger overflow and rebuilt balance tank, a black marble feature wall with a planter and a water curtain, a smaller reworked pump room with a salt chlorinator and a new filter, new flat lights, fibre optics and projection; refinished throughout; paths, terraces, stairs and kitchens in PebbleCrete
The pool and the black marble wall from the entrance
The balance tank and the overflow were rebuilt, and the overflow was made larger and symmetrical.
CompletedPrivate Villa, Pasak
New pool finish and coping, the pool system, the jacuzzi pipework and a rebuilt surge tank
The finished pool before filling
The surge tank was leaking. We rebuilt it as a new tank inside the old one.
Guides on this topic
Questions we are asked
Can a pond be waterproofed without tiling it?
Yes, provided the pond has a concrete base. For concrete ponds and tanks we use coatings that hold up in the open and can carry colour, so the waterproofing can also be the finished pond surface. A pond built on a liner cannot be waterproofed by us.
What is a tank-in-tank rebuild?
A new balance tank is formed inside a leaking old one, and in difficult cases the same approach is possible for a pool shell. The inspection shows whether the existing structure and space around it make this suitable.
Does the tank need to be emptied?
Yes. Waterproofing goes onto a clean, dry concrete surface, so the tank or pond is emptied for the work. For below-ground tanks and ponds, draining in the wet season or where groundwater is high is planned with care to manage outside water pressure.
Related work
Leak repair & waterproofing
A leaking pool wastes water, washes away treatment and can undermine the terraces around it. We trace and repair leaks in pools, overflows, balance tanks and buried pipework, then waterproof the shell where it needs it.Roof & terrace waterproofing
Water that gets through a roof, terrace or balcony shows up as stains, peeling paint and damp in the rooms below. Pebble Pools waterproofs roofs, terraces, balconies and slabs for villas, hotels and resorts in Phuket and across Thailand.Basement & pit waterproofing
Rooms below ground take water from the soil around them. Pebble Pools waterproofs basements, pits, pump rooms and other rooms below ground for villas, hotels and resorts in Phuket and across Thailand. When the outside cannot be reached, we work from the inside.Tell us where the pool is and what you want changed.
Send photos → discuss the work → site assessment if needed → quotation
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