Why a roof starts leaking after a solar install, how to tell a mounting penetration from an ordinary roof defect, and what a proper repair has to itemise.
A rooftop PV array is held down by a set of fixings — often dozens across a full array — that each go through the weatherproof layer of the roof. The panels are the part everyone looks at; the part that leaks is underneath them. On a domestic Klang Valley install there are usually four penetration types, and every one of them is a hole that was watertight on the day it was made and is now several years older.
| Penetration | How it should be weathered | How it fails |
|---|---|---|
| Bracket foot or roof hook (tiled roof) | Fixed into the rafter or a batten, with a purpose-made flashing tile or a dressed metal flashing under and over the fixing | Drilled straight through the tile and sealed with a bead of silicone, which UV-degrades and cracks |
| Through-fixing screw (metal roof) | Driven on the crest of the rib, into purlin or a spreader, with a bonded washer | Driven through the pan, where water actually runs, or over-tightened so the washer is crushed and split |
| Rail bolt and spreader plate | Sealed to the sheet or tile with a compatible flashing, load spread across more than one fixing | Under-fixed, so wind load works the bolt loose and the seal opens |
| DC cable and conduit entry | Through a raised gland or a weathered upstand, entering above the water line | A hole cut in the sheet or tile and filled, with the cable running downhill into it |
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💬 Get Your Instant QuoteNotice that none of those failures is about the panels. They are all roofing details, which is why the person who installed the array is often not the person best equipped to repair them, and why the two trades need to meet on your roof rather than blame each other over WhatsApp.
Because water travels along battens, rafters and the underside of sheeting before it drips, the wet patch on your ceiling is a clue rather than an address. Work up the slope from the stain, and start with whatever sits directly above it.
| What you see | Most likely cause | Check this first |
|---|---|---|
| Leak started within a season of the install, directly under or just below the array | A mounting penetration that was never properly flashed | Every bracket foot on that roof face, uphill of the stain |
| A neat line of drips following one row of fixings | Perished or crushed washers on a fixing line | The screw row, not the sheet between them |
| Leak only in storms with wind from one direction | Wind-driven rain past laps, or a degraded underlay | the sarking under the tiles, before you touch the array |
| Stain appeared a year or more after the install, away from the array | An ordinary roof defect that has nothing to do with the panels | Valleys, flashings and ridge mortar — see tile roof leak repair |
| Cracked tiles scattered near the access route | Foot traffic during installation or a later service visit | The path from the ladder to the array |
| Water pouring from one point during heavy rain only | Concentrated runoff off the panel edge overwhelming a lap or gutter | What sits directly below the panel drip line |
On the concrete-tile roofs most Malaysian terrace, semi-D and bungalow homes carry, a bracket has to reach a rafter or a batten, which means the tile above it has to be lifted, cut or replaced. Done properly, the fixing lands in structure and a flashing piece — either a purpose-made flashing tile or a dressed metal apron — carries water over the top of it and out onto the tile below. Done in a hurry, the installer drills through the face of the tile and relies on sealant. Sealant is a legitimate secondary seal and a poor primary one: it sits fully exposed to Malaysian UV on a surface that reaches high temperatures every afternoon, and once it cracks the hole is simply an open hole.
Two secondary problems come with the same job. Tiles crack under foot traffic, and installers walk the roof repeatedly during a fit-out; the tile that fails is often not the one with the bracket on it. And tile nibs — the small lugs that hook each tile over its batten — snap when tiles are levered up and dropped back, so a tile can look seated and still be free to lift in a gust. Both are cheap to put right while someone is already up there, and expensive to find later because the array is now sitting on top of them.
On metal deck roofs — extensions, awnings, factory and warehouse roofs — every fixing is a hole through the roof kept dry by a bonded rubber washer. Solar mounting adds a new set of those holes, and the two mistakes that matter are position and torque. Fixings belong on the crest of the rib, above the water path; a screw driven through the pan sits in the channel that water runs down, and no washer stays ahead of that for long. Over-tightening crushes and splits the washer, under-tightening leaves it loose enough to weep. Thermal movement then works on every one of them, because a metal roof in Malaysia expands and contracts through a wide temperature swing every single day.
Non-penetrating clamp systems exist for standing-seam and some trapezoidal profiles, and where the roof profile allows them they remove the problem rather than manage it. Where fixings are unavoidable, the honest answer is that they are a maintenance item with a finite life, and they should be inspected on a schedule instead of after the ceiling stains. The wider failure pattern is set out in metal roof leak repair.
On a reinforced-concrete flat roof the calculation changes, because the waterproof layer is a membrane and every bolt through it is a deliberate breach of the one thing keeping the slab dry. Two approaches are used: bolted-down frames, where each fixing needs a proper upstand and the membrane has to be dressed up and terminated around it, and ballasted frames, which sit on the roof under weight and make no hole at all. Ballast has its own consequences — the roof has to be able to carry it and the drainage path must stay clear underneath — but it does not perforate the membrane.
Whichever is used, the membrane under the array becomes very hard to inspect and even harder to renew. If your flat roof is already near the end of its waterproofing life, the sensible sequence is to renew the membrane first and mount afterwards, not the other way round. Flat roof waterproofing covers the systems, and how long waterproofing lasts covers the timing question.
This matters, because it decides who you call and who pays. Three tests separate them without anyone getting on the roof.
The awkward middle case is real and worth naming: an old roof that was already marginal, plus new penetrations, plus foot traffic. Nobody caused that alone. It is also the case where a joint site visit settles things far faster than an argument.
Responsibility here is a matter of the contracts you signed and the evidence you can show, not a rule of thumb, so the useful thing to do is build the evidence before anyone starts talking about cost.
If you want a checklist for vetting whoever ends up doing the work, questions to ask a waterproofing contractor covers it, and waterproofing scams covers the patterns to walk away from.
There are usually two separate documents in play — the solar contractor’s workmanship warranty on their installation, and any roofing or waterproofing warranty from an earlier re-roof or recoat. They are contracts, and the only reliable answer to “does mounting solar affect my roof warranty?” is the one written in yours. Do not assume it either way. Read the document, and if the wording is not clear, ask the issuer in writing before the install rather than after the first storm.
Ahead of an installation, the practical asks are: a written statement of how each penetration will be weathered, on what roof type; confirmation of who is responsible if a roof leak appears afterwards and how that will be handled; a note of any existing roof defects the installer found, before they start; and photographs of every completed penetration. After an install, ask for the same photographs if you were not given them. What a waterproofing warranty is actually worth explains how to read one of these documents and which clauses matter.
A mounting leak is repaired at the penetration, not at the ceiling. In outline: isolate the array electrically and have the panels over the affected section removed by the solar contractor; expose the fixing and the substrate around it; establish whether the leak is the fixing itself, the tile or sheet it passes through, or a wider defect that was simply revealed; then reinstate properly — a flashing tile or dressed metal apron on tiles, a fresh fixing on the crest with a new bonded washer on metal, and a proper upstand on a membrane roof. Damaged tiles nearby get replaced at the same time, and the underlay is checked while it is open, because that is the only cheap moment to do it.
Then the panels go back. Refitting is the solar contractor’s work, not the roofer’s, which is why the two need to be sequenced rather than booked separately a fortnight apart. Sealant is used as a secondary seal at the end of that sequence, never as the repair itself; a repair that consists only of more silicone is the tampal cycle described in why waterproofing fails, and it buys a season at most.
The roofing side of the work is priced like any other roof repair. These are the market bands we would use for a first conversation (market estimate 2026, indicative Klang Valley):
| Work | Market range (2026, Klang Valley) | Notes |
|---|---|---|
| Tiled / metal roof repairs | RM500 – RM3,000 per job | flashing, tile replacement and re-fixing at the penetrations |
| Roof waterproofing (all systems) | RM8 – RM20 per sq ft | only if the whole roof has aged out, not for a bracket leak |
Read the second row as a warning rather than a quote: a handful of badly flashed brackets is a repair, and anyone quoting a whole-roof system for it should be asked to justify the scope. On our own side, ClickBina leak detection and assessment is RM300 – RM800 per visit, and it is waived if you proceed with the repair — that is our price, not a market range. Panel removal and refitting is quoted by the solar contractor and sits outside the roofing figure entirely, so ask for it as a separate line before you compare anything. Roof repair cost breaks the roofing side down further, and roof waterproofing cost covers the per-square-foot systems if the roof genuinely does need renewing.
A quote that says only “repair solar roof leak” with one figure is not comparable with anything, and it gives you nothing to hold anyone to.
Three constraints shape the programme. First, electrical isolation: nobody should be lifting panels or working between rails on a live array, so the solar contractor books the isolation and the reinstatement. Second, access. Panels are awkward and the roof around them is crowded, so an array often forces proper access — a roof ladder or a scaffold tower — where a bare roof would not, and that cost is real and belongs on the quote rather than in a surprise. Third, weather. Roofs are opened in sections and each section is closed before the crew leaves; nothing is opened in front of an afternoon storm, and nobody should be on wet tiles or wet metal sheeting at all.
Practically that means a solar-related repair is often staged across mornings rather than done in one long day during the monsoon months, and a contractor who promises otherwise is telling you what you want to hear. Plan the work into a drier stretch where you can, and use the monsoon roof preparation checklist to decide what has to happen before the wet season rather than during it.
Ask for a hose test on completion: water played on the repaired area from above, working uphill, for long enough to load the detail, with someone inside the roof space watching with a torch. It is simple, it is cheap, and it is the difference between a repair that has been checked and a repair that has been hoped for. If the leak was intermittent and wind-dependent, the honest position is that a hose test cannot fully reproduce it, so agree in advance what happens if it reappears in the next storm.
After that, treat the array as something that has to be inspected, not something that has been solved. Once a year, before the wet season, look at the fixing lines, the flashings, the cable entry, and the gutters and valleys the panels now discharge into — panel edges concentrate runoff into narrow lines, and a gutter that coped before can overflow after. Clearing gutters and valleys is the cheapest leak prevention there is; gutter cleaning and scheduled roof maintenance cover the routine.
ClickBina repairs roofs across Kuala Lumpur and Selangor, including roofs that now carry a solar array. We diagnose before we quote: we want photographs of the stain, the roof face and the array, and where the pattern is unclear we do a paid detection visit at RM300 – RM800 per visit and waive it if you proceed. We will tell you plainly whether what we find is a mounting defect, an aged roof, or both — and we work alongside your solar contractor for the panel removal rather than pretending roofing and PV are one trade. See all of our waterproofing and leak repair services, or send us the photos on WhatsApp for a fixed quote.
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