Leakage from the Flat Above in a Mumbai Society: Who Is Responsible and How It Gets Fixed

Leakage from the flat above is one of the commonest disputes in Mumbai societies. How to find the real source, what society bye-laws generally say about who pays, and how the repair gets coordinated.

Leakage from the flat above is one of the most common, and most bitter, disputes in Mumbai housing societies. A brown ring appears on the bathroom ceiling, the paint starts to bubble, and within a week three households and the society committee are arguing about whose fault it is. In most cases the argument starts before anyone has established where the water is actually coming from. This article sets out how to find the real source, what society bye-laws generally say about who is responsible, and how the repair is coordinated so that it is done once and done properly.

It is written by Chamunda Constructions, a civil and finishing contractor based in Kandivali West. The firm was founded in 2004 by Bhadresh Chavda, and bathroom waterproofing and leak repairs are a large part of the work we do for flat owners and societies across the western suburbs. We are not lawyers, and the sections on bye-laws and responsibility are general information drawn from published sources named in the text, not legal advice. Your society's own bye-laws and resolutions are what actually govern, and a qualified advocate can advise on a specific dispute.

Leakage from the flat above: why it is so common in Mumbai

Most Mumbai flats sit directly under another flat's bathroom and kitchen, because wet areas are stacked one above the other to share vertical drainage. That is efficient for plumbing, and it means that every failure in a bathroom floor becomes the problem of the flat below. Add older buildings with original waterproofing, concealed galvanised iron pipes that corrode from the inside, frequent bathroom renovations by different contractors, and four months of monsoon humidity, and leaks are close to inevitable over the life of a building.

The leak usually shows on the ceiling of the bathroom below first, sometimes on the adjoining bedroom wall, and sometimes much further away, because water travels along the slab before it finds a way down.

Start with the source, not with the blame

The single most useful thing anyone in this situation can do is establish the source before deciding responsibility. Water in a ceiling can come from at least six places, and only some of them are inside the flat above.

• The bathroom floor above: failed or missing waterproofing under the tiles, especially around the floor trap and at the junction of floor and wall.
• The floor trap or nahani trap: a cracked trap or a gap between the trap and the slab lets water bypass the waterproofing entirely.
• Concealed supply lines above: a pinhole leak in a hot or cold water line inside the wall or floor of the flat above, which leaks whether or not anyone is using the bathroom.
• The toilet outlet: a poor joint between the WC and the soil pipe, which leaks each time the toilet is flushed.
• The common drainage stack: the vertical soil and waste pipes, and the duct they run in, which are usually common property.
• The terrace or external wall: for a top-floor flat, or for leaks that only appear in heavy rain.

How to read the pattern of the leak

Before anyone opens a tile, the pattern of the leak tells you a great deal. These are the observations we ask flat owners to make over a few days.

• Does it leak all the time, even when the flat above is locked and empty? That points to a pressurised supply line, not to drainage or waterproofing.
• Does it get worse soon after the bathroom above is used for bathing? That points to the floor waterproofing or the floor trap.
• Does it appear each time the toilet above is flushed? That points to the WC outlet joint.
• Does it only appear during heavy rain? That points to the terrace, the external wall, a window or an external pipe.
• Is the stain right next to the vertical duct or the common pipe? That raises the possibility of a common line.
• Is the water clean, or does it smell or leave a dark residue? Dirty water usually means drainage rather than supply.

The tests that actually find it

Once the pattern suggests a likely source, a few simple tests usually confirm it. A competent plumber or waterproofing contractor can do them in a day with the cooperation of the flat above.

• Supply line pressure test: shut every tap in the flat above, note the water meter reading if there is one, or isolate the line and pressurise it with a test pump, and watch for a drop. A falling reading with every tap closed means a concealed leak.
• Ponding test: plug the floor trap of the bathroom above, flood the floor with a few centimetres of water, mark the level and leave it for several hours or overnight, then check the ceiling below. If the stain spreads, the floor waterproofing has failed.
• Trap test: run water directly into the floor trap only, without flooding the floor, to separate a trap leak from a floor leak.
• Dye test: add a coloured dye to the WC or the floor trap above and look for coloured water below.
• Moisture meter and thermal camera: these help map how far the damp has spread and which direction it is coming from, and they are useful for showing the result to everyone involved.

Each test takes cooperation, which is where many disputes stall. That is one reason the society usually has to be involved early.

What the model bye-laws generally say

Most Mumbai co-operative housing societies have adopted some version of the model bye-laws issued by the state's Commissioner for Co-operation and Registrar of Co-operative Societies, with the 2014 version being the one most societies follow today. Bye-law numbering and wording differ between versions and between societies, so what follows is a general description of how commentators have read the model bye-laws, not a statement of what your society's bye-laws say.

• Society repairs: the model bye-laws list repairs that the society carries out at its own cost, which typically include common pipelines and drainage lines, the terrace, the external walls and the staircase. In a Moneylife column published on 10 July 2025, Shirish Shanbhag wrote that repairing terrace leakage affecting a top-floor flat is the society's responsibility under bye-laws 68(a) and 159(a).
• Member repairs: internal repairs within a flat are generally the member's responsibility. Writing in the Indian Cooperative in 2014, I C Naik noted that the 2009 model bye-laws treated internal leakages from a toilet or sink as a cost for the concerned flat holder, with intimation to the society, while leakages from common pipelines were for the society.
• Damage to other flats: where a leak from one member's flat damages another's, commentators generally treat the member whose fittings or waterproofing failed as responsible for putting it right, with the society playing a coordinating role.

The short version, in general terms: if the source is inside the flat above and belongs to that flat, such as its bathroom floor, its trap or its concealed supply lines, the cost usually falls on that member. If the source is a common element, such as the drainage stack, the terrace or an external wall, the cost usually falls on the society. If it is unclear, the tests above are what settle it.

The 2026 changes: new rules and draft model bye-laws

Two developments this year matter. First, the Maharashtra Co-operative Societies (Amendment) Rules, 2026, notified in June 2026, added a dedicated chapter for housing societies, which we have summarised in a separate article on the 2026 society rules. Second, on 17 August 2026 the state released draft model bye-laws for co-operative housing societies for public comment, with comments invited until 27 August 2026, as reported by Moneylife. The existing model bye-laws were last revised in 2014.

According to Moneylife's summary of the draft, it divides repair responsibilities between the society and members, and where a member's failure to repair causes damage to neighbouring flats or common areas, the society may issue a notice, carry out the work and recover the cost from that member. The draft also requires members to give reasonable access to the society and its authorised contractors or technical experts for inspection and repairs of common services, structural audits or statutory requirements, and allows the society to enter a flat without prior notice in an emergency involving danger or the failure of essential services.

At the time of writing, we have not seen a final notified version, so treat these as proposals. If they are adopted in that form, they would give societies a clearer route for exactly the situation this article is about: a leak from one flat into another, and an upstairs owner who will not act.

What to do if the flat above will not cooperate

This is the hardest case, and we can only describe the usual practical sequence, not legal remedies. A Moneylife column published on 25 June 2026 on a flat-to-flat leakage dispute suggested starting with a written complaint to the society requesting an inspection and repair, and escalating to the municipal ward office and, if necessary, the civil courts if the problem persists. Your advocate can tell you which route suits your situation.

• Write to the society secretary with photographs, the dates the leak started, and a request for a joint inspection.
• Ask the committee to write to the member above, requesting access for inspection on a specific date.
• Keep a dated record of every communication and every visit.
• Get a written report from a contractor or engineer identifying the source, if you can obtain access.
• If the committee will not act, a general body meeting or the routes described above may be the next step, on advice.

In our experience, most upstairs owners are not refusing out of malice. They are worried about being blamed for something that may not be theirs, or about the cost and disruption of breaking a bathroom they recently renovated. A neutral inspection with tests usually changes the conversation.

What a useful inspection report contains

When responsibility is disputed, a short written report from whoever ran the tests does more than any amount of argument in the society WhatsApp group. A useful report does not need to be long, but it should let someone who was not present understand what was found.

• The date of the inspection, who was present, and which flats and common areas were seen.
• Photographs of the damage below and of the suspected source above, with locations marked.
• Each test carried out, how it was done, how long it ran and what the result was.
• The likely source, stated plainly, with the reasoning.
• Whether the source appears to be part of the flat above or a common element.
• What repair is recommended, and in what order.
• Anything that could not be checked, and why.

How the repair gets coordinated

Once the source is agreed, the repair itself involves at least two flats and often the society. A clean sequence avoids doing work twice.

• Agree in writing who is commissioning and paying for which part of the work: the source repair above, the ceiling repair below, and any common pipe work.
• Fix the source first. Nothing done below will last until the water stops.
• Test the repair before it is covered. For a bathroom floor, that means a ponding test after waterproofing and before tiling.
• Let the slab below dry. A soaked slab can take several weeks to dry out, longer in monsoon humidity.
• Repair the ceiling below only after it is dry: scrape loose plaster and paint, treat any efflorescence or fungus, apply a suitable primer and repaint.
• Record the completion with photographs on both sides, and ideally a short note signed by both members.

What a proper bathroom leak repair involves

There is a quick version and a proper version of most leak repairs, and they are not the same thing.

• Quick fixes: re-grouting the tile joints with epoxy, or injecting chemical sealant through the joints. These can reduce a leak for a while but rarely stop one caused by failed waterproofing under the tiles.
• Trap replacement: replacing a cracked floor trap and properly sealing it to the slab, which often requires lifting the tiles around it.
• Line replacement: replacing a leaking concealed supply line, ideally with a modern pipe material, and pressure testing it before the wall is closed.
• Full waterproofing redo: removing the floor tiles and bedding, cleaning the slab, treating the corners and pipe penetrations, applying a proper waterproofing membrane with an upturn on the walls, ponding testing it, then laying a protective screed and retiling.

For a bathroom where the waterproofing has genuinely failed, the full redo is usually the only repair that lasts. We go through the waterproofing mistakes that cause these leaks in a separate article.

The ceiling below: fixing it properly

The flat owner below is often eager to repaint the ceiling as soon as the leak stops. That is understandable and usually a mistake. Paint over a wet ceiling blisters and peels within weeks. The right sequence is to wait until the ceiling is genuinely dry, which a moisture meter can confirm, then scrape back to sound plaster, replaster any patches that have softened, treat salt deposits and fungus, prime, and apply the finish coats. If the ceiling has a POP or gypsum false ceiling, damaged boards or POP may need to be cut out and replaced.

Leaks caused by a renovation upstairs

A specific and common situation is a leak that starts soon after the flat above has renovated its bathroom. In that case, the timing is strong evidence, but not proof. The renovation may have damaged the existing waterproofing, the new contractor may not have waterproofed at all, or the renovation may simply have revealed a pre-existing problem.

Societies can reduce this risk at the start. Many Mumbai societies now require a written undertaking, a refundable deposit and sometimes a ponding test before tiling as conditions of a renovation NOC. I C Naik suggested in 2014 that deposits be refunded only some months after completion, once the flat below confirms there is no leak. We cover the NOC process in our article on society permission for flat renovation.

Prevention for societies

• Make a ponding test before tiling a condition of every bathroom renovation NOC.
• Keep a record of which flats have had bathrooms redone, when and by whom.
• Inspect the common drainage stacks and ducts periodically, especially in older buildings.
• Plan terrace waterproofing and external wall repairs as scheduled maintenance, not emergency work.
• Encourage members to report leaks early, before they spread.

Leaks in the monsoon are a different problem

If the leak appears only during heavy rain, it is very unlikely to be the flat above's bathroom. The usual sources are the terrace for top floors, external walls, window frames, balcony slabs and external pipes. Those are often common property, and the post-monsoon months are the right time to fix them. We have written about finding the source of monsoon seepage, and about terrace waterproofing, in separate articles.

How Chamunda Constructions handles leakage cases

When a flat owner or society calls us about a leak, we start with an inspection of both flats and, where relevant, the common areas, then run the tests needed to identify the source. We write up what we found in plain language with photographs, so the members and the committee can agree on responsibility before anyone spends money on repairs. Once that is agreed, we carry out the repair: replacing traps and lines, full bathroom waterproofing with a ponding test before tiling, and the ceiling and paint repair below once it has dried. Bhadresh Chavda reviews leak cases personally, because getting the diagnosis right is what saves both households from paying twice.

If you have a leak from the flat above, or your society is dealing with one, book a site visit through the contact form. We will inspect, test, and tell you where the water is coming from before we suggest any repair.