Pond waterproofing and relining: polyurea, EPDM and concrete sealing
When a concrete pond, plaster fountain or old liner is failing in more than one spot, a new waterproof layer costs less than chasing cracks year after year.
Sealing options
- Polyurea spray membrane: seamless, flexible, bonds to concrete and most liners; fish-safe once cured. Our default for concrete ponds and fountains.
- EPDM relining: new 45-mil rubber liner over the existing shell with underlayment; the most economical fix for liner ponds.
- Crack injection and cementitious coatings: for structurally sound concrete with isolated cracks.
The process
Fish are held in aerated tanks. The shell is drained, cleaned, ground or primed, and all penetrations (drains, returns, lights) are re-flanged. The membrane is applied, cured and flood-tested before rock and water go back. Most residential resealing jobs are three to five days.
Signs you need resealing help
- A concrete pond or fountain is cracking in more than one place
- The liner has been patched repeatedly
- Plaster or tile is flaking and the basin stains
- A leak test found loss through the shell, not the plumbing
What drives the cost
Resealing is priced by surface area and preparation: polyurea runs higher per square foot than EPDM but bonds to concrete and lasts longer; crack injection is the cheapest fix for isolated cracks in sound concrete. Fish holding and refilling are included.
What this service covers
Pond resealing & relining sits under the wider heading of waterproofing services. Clients tend to call it pond sealing or pond liner replacement; whatever the name, the work breaks down into a few distinct jobs:
Polyurea spray membrane
Seamless, flexible, fish-safe once cured; our default for concrete ponds and fountains.
EPDM relining
New 45-mil rubber liner over the existing shell with underlayment; the economical fix for liner ponds.
Crack injection
Epoxy or polyurethane injection for structurally sound concrete with isolated cracks.
Cementitious waterproof coatings
Brush- and trowel-applied coatings for basins and walls where a membrane isn't practical.
Fountain basin resealing
Basins stripped, primed and recoated with potable-rated sealers.
Tile and plaster basin sealing
Clear and tinted sealers for tiled and plastered fountains where the substrate is sound.
Terms you'll hear from our technicians on this work: polyurea, EPDM 45-mil, geotextile underlayment, primer, flange and penetration sealing, flood test, cure time, fish-safe coating, potable-water rated.
Where we offer it
Routed service through Orange County, Los Angeles, San Diego County, the Inland Empire and the Coachella Valley, with construction and commercial crews traveling to Arizona.
Pond Resealing & Relining across Southern California and Arizona
Orange County home base, routed crews from Los Angeles to San Diego and the desert. One call, one crew, written findings.
Before and after: resealing calls
Customer story
A liner leak found the right way, in Long Beach
“They came back about three different times to make sure the leak was in the liner, without just saying, oh, we need to pull the liner out. It could have been a leak in the pipe. It's so clear, and you can hear the waterfall. I would recommend you guys to anyone. Fantastic job.”
Homeowner, Long Beach, CA
A Long Beach homeowner came home to an empty pond. Koi Pros came back three times to confirm the leak was in the liner and not the plumbing before recommending a new liner, then rebuilt the pond with the waterfall he can hear from the house.
Watch: a waterfall and pond repair and reseal in Orange County
A leaking community stream and waterfall, start to finish: drain and vacuum, grind and patch the cracks, spray the sealer, refill, and the waterfall running again. About two minutes. This is the same crew that handles resealing.
Guides on resealing
Repair · 4 min
How To Repair A Cement Fountain
Easy guide to repair a cement fountain—fix cracks, seal leaks, and restore its charm with simple DIY techniques and...
Construction · 9 min
A Few Tips & Tricks on Backyard Waterfall Installation
We all have been awed by the soothing sounds and serenity of waterfall, always stopping and gazing when out we come...
Fountains · 6 min
FAQs About Water Fountain Maintenance and Installation
Find answers to common questions about water fountain maintenance and installation. Learn tips to keep your fountain...
Questions about resealing
Is polyurea safe for koi?
Yes, once fully cured. We use potable-water-rated formulations and flush the system before fish are reintroduced.
Can you reseal a fountain without removing the tile?
Often, yes. Clear and tinted sealers are available for tiled and plastered basins where the substrate is sound.