JMB Common Area Waterproofing
in Malaysia (2026)

Whose leak is it — JMB or owner?

The first question every committee faces when a leak complaint lands is whose repair it is. Under Malaysia’s strata framework, the JMB or MC maintains common property — everything outside the individual parcels that serves the building as a whole. That puts the rooftop, the external facade, the water tanks, the main pipe risers, corridors, stairwells and lift pits squarely on the committee’s books, funded by the charges every owner pays. What sits inside a parcel — a bathroom floor, an owner’s renovation, a unit’s own piping — is the owner’s to fix. Our JMB responsibilities guide covers the legal framework in full; the table below is the quick reference a committee actually needs when the complaint email arrives.

Getting this split right early prevents the most corrosive dispute in strata living: the committee paying for an owner’s problem, or an owner left holding a common-property leak that nobody will own. Put the split in writing in your house rules and apply it consistently — tenant complaints get resolved faster when the answer is a policy, not a debate.

Inter-floor leaks & disputes

The messiest cases are ceiling leaks between units, because the cause may be the upstairs bathroom (owner), a common riser (JMB) or both at once. Malaysian strata law provides a formal inspection-and-certificate process to determine the cause and assign the cost, and committees that follow it — inspect, document, certify, then repair — resolve disputes far faster than those that argue in the residents’ WhatsApp group. Our inter-floor leakage guide walks through that process step by step, including the notice and timeline rules. On the repair itself, most bathroom-slab leaks are sealed from below by PU injection without hacking the upstairs unit: ClickBina charges a flat RM650 for one bathroom ceiling (indicative 2026, Klang Valley), which usually makes the fix cheaper than the argument. The committee’s job is to run the process quickly and neutrally — a certificate nobody disputes is worth more than a month of finger-pointing.

Sinking fund vs maintenance fund

Committees run two purses, and waterproofing draws on both. The maintenance fund — built from the monthly charges — pays for routine upkeep: patch repairs, joint resealing, gutter clearing, small leak call-outs. The sinking fund exists precisely for capital works: a full rooftop re-waterproofing, a facade recoating programme, tank refurbishment. Paying a capital project out of the wrong purse is a classic audit finding and can starve day-to-day maintenance for a year, so classify the job before you tender it.

Major sinking-fund works normally have to be budgeted and approved through the AGM cycle, so the survey and tender work described below should start months before the money is actually needed — a committee that begins scoping in the wet season can realistically award works after the next AGM.

Condition survey & scope document

Never put “waterproofing works” out to tender as a one-line item — you will get back five quotes for five different jobs. Start with a condition survey: where the water actually shows, moisture readings, the age and build-up of the existing membrane, and the state of outlets, upstands, joints and tanks. Turn the findings into a short scope document that states the areas and quantities, the surface preparation required, the system build-up expected and the warranty terms wanted. That one document is what turns a tender from guesswork into a genuine comparison, it becomes the technical annex of your AGM paper, and it is the single highest-value hour a committee can spend on a waterproofing project. ClickBina prepares committee-ready scope documents as part of quoting larger common-area works.

Running the tender properly

With a scope document in hand, invite at least three contractors, walk each one through the site, and require itemised pricing against your scope — not lump sums. Check each bidder’s registration, insurance and, most importantly, a track record on occupied strata buildings, which are a different discipline from empty sites: residents, lifts, noise windows and water shutdowns all have to be managed while the work proceeds. Our waterproofing contractor guide lists the credentials to verify before a bidder makes the shortlist. Score the tender on scope compliance, track record and warranty — never on price alone — and record the scoring so the committee’s decision survives scrutiny at the next AGM.

Comparing like-for-like quotes

The classic strata mistake is taking the lowest of three numbers that were never comparable. A cheaper bid often means a thinner build-up, less surface preparation, excluded access costs, or optimistic provisional quantities that balloon later as variation orders. Force every bidder onto the same scope document, ask each what is excluded, and get the system, coverage rates and number of coats in writing. Our waterproofing quotation guide shows line by line what a proper quote should contain — a committee member who reads it once will save the building real money at every tender afterwards.

Warranty terms that protect the building

For sinking-fund works, demand a written warranty covering both workmanship and materials — 5 to 10 years is the normal band for full re-waterproofing — and check whether the membrane manufacturer stands behind the applicator. Then read the conditions: most warranties require the roof to be kept clean and periodically inspected, and are void if another contractor patches over the system. That is why a scheduled roof maintenance arrangement pairs naturally with a big project — it keeps the warranty alive and catches small failures inside the warranty window, when they are the contractor’s cost rather than the building’s. Our waterproofing warranty guide explains the fine print committees should insist on before signing.

Phasing big jobs

A full-building programme rarely needs to happen in one financial year. Roofs can be re-waterproofed zone by zone, facades elevation by elevation, tanks one at a time — worst-affected areas first, each completed phase protected by its own warranty. Phasing spreads the sinking-fund draw across budget years, keeps the levy conversation manageable at the AGM, and lets the committee judge the contractor’s workmanship before awarding the next phase. It also keeps an occupied building liveable: one zone of noise and odour at a time instead of the whole roof at once. For the flagship case — the condominium rooftop — our condo rooftop JMB guide works through a full phased project with numbers a committee can adapt.

Communicating with residents

Waterproofing works on an occupied building succeed or fail on communication. Circulate notices well before works start: what is being done and why, which blocks and dates, working hours and noise windows, any water shutdowns for tank works, and a single contact for complaints. Warn top-floor residents specifically about access, odour and vibration, and photograph affected ceilings before and after so that damage claims stay clean. Where unit interiors were damaged by a common-property leak, point owners to how their claims interact with the building’s master policy — our strata insurance guide covers what that policy does and does not pay for. Committees that communicate well spend less time in dispute and get faster access to units when inspections are needed.

Indicative common-area costs

Every building differs, but these are the planning figures Klang Valley committees can budget around (indicative 2026, Klang Valley):

Use the ranges to sanity-check tenders, not to replace them — access, condition and real quantities move every number, which is exactly why the scope document matters.

Why JMBs work with ClickBina

ClickBina works with JMBs, MCs and property managers across the Klang Valley on exactly these jobs — rooftops, facades, water tanks, risers, corridors and lift pits — with itemised committee-ready quotes, scope documents a tender can be built on, and WhatsApp replies within the hour. We understand the strata side as well as the waterproofing side: our JMB guide cluster is the reference many Klang Valley committees already use. Send us your building’s leak list and we will help you separate the owners’ issues from the committee’s — then survey, scope and price the committee’s properly.