Skip to content
RoofonixWaterproofing experts, Vijayawada
Water tanks & sumps

Water tank and sump waterproofing

A tank is the only part of a building that is meant to hold water, which is why a leak there is never a small one. It runs all day, not only when it rains. We seal a tank from the inside, with a coating rated for drinking water, so the water stays where you put it and the slab underneath stops paying for it.

Water tanks & sumps — how it happens and how we fix itlevel drops overnightholds, and the slab stays dry
5.0 ★
195+ ratings
Vijayawada
our base — same-day visits in the city
All days
site visits, including Sundays
AP & Telangana
we travel for larger jobs

You probably need this if…

  • A wet patch on the slab or the wall directly under the tank
  • The level drops overnight when nobody has used any water
  • White salt marks or algae running down the outside of the tank
  • The sump wall is damp, or ground water is getting into the sump
Why it happens

What causes it

The same wet patch can come from different places, and each one needs a different fix. This is what we look for on site.

  • 01

    The joint at the base

    The line where the wall meets the floor is where two pours met. It is the first place a tank lets go, and the hardest one to see from outside.

  • 02

    Plaster used instead of a coating

    Cement plaster inside a tank is not waterproofing. It holds for a few years, softens, and then the water is straight onto the concrete.

  • 03

    Pipe entries left open

    Inlet, outlet, overflow and washout all pass through the wall. Each one is a gap packed with mortar, and mortar around a vibrating pipe does not stay tight.

  • 04

    Filled before it had cured

    A new tank put into use too early never gains the strength it was designed for, and stays porous.

  • 05

    Ground water pushing into a sump

    A sump can leak inward as well as outward. Water coming in from the soil is under pressure and has to be stopped before anything goes on the surface.

How we do it

Our water tanks & sumps process

Step by step, in this order. Nothing is skipped to finish a day early.

  1. 01

    Empty and clean

    The tank is drained, the sludge taken out, and every loose patch of old plaster removed until the surface underneath is sound.

  2. 02

    Open the joints and pipe entries

    The base joint and each pipe entry is cut into a groove, cleaned and packed with a plug mortar that sets in minutes, even against running water.

  3. 03

    Cove every corner

    The wall-to-floor line and the vertical corners are packed into rounded fillets, so the coating has no sharp edge to crack along.

  4. 04

    Two non-toxic coats

    Two coats of a coating certified for potable water are brushed one across the other, each dried fully before the next goes on.

  5. 05

    Cure, fill and drop test

    The coating is cured, the tank is filled, the level is marked, and it is read again after 48 hours. That mark is what tells you the job held.

What is included

  • Draining, cleaning and disposal of the sludge
  • Base joint, corner and pipe-entry treatment before any coating
  • Two coats of a coating certified non-toxic for drinking water
  • A 48-hour drop test with the level marked, witnessed with you
  • The tank handed back cleaned and ready to fill

Free site visit. You get the measured area and a written scope before any work starts.

+91 73823 58857
Questions

Frequently asked

Book it

Request a site visit

Tell us what you are seeing and where. We will come and check, measure the area and give you a clear scope — the same day wherever we can.

Based in Vijayawada, so we are quickest in and around the city — and we take up work across Andhra Pradesh and Telangana.

Request a site visit

Takes one minute. We reply on WhatsApp or call you back the same day.

Tell us where it leaks.

We will come and check before the next rain, measure the area and give you a clear scope in writing.

WhatsApp us+91 73823 58857