METAL ROOF WATERPROOFING SPECIALIST
Metal Roof Waterproofing
by snapping and fastening individual panels together to the roof deck. As such, over time, it is the seams and joints that are most vulnerable to degradation, thus allowing for water penetration. To prevent such, a quality initial waterproofing job and constant maintenance thereafter is recommended.
Since metal roofs come in a variety of profiles, individual assessment by a waterproofing expert is required to determine the areas where various chemical coats and sealants need to be applied in order to create a leakproof membrane system.
FAQs
Why do metal roofs in Singapore need waterproofing?
Metal roofs in Singapore need waterproofing because seams, screw holes, and panel overlap joints are the first failure points under tropical heat and heavy rain. Constant thermal expansion loosens fasteners and breaks the original sealant. Once water reaches the underside, rust spreads from the inside out. A liquid membrane sealed across seams and fasteners prevents this.
What causes metal roof leaks?
Metal roof leaks are usually caused by five things: failed sealant at panel seams and overlaps, loose or rusted fastener screws, corrosion at flashing around vents and skylights, ponding water on low-pitch sections, and damaged panel coatings exposing bare steel to acid rain. Most leaks start at joints, not on the panel face itself.
What waterproofing membrane works best for metal roofs?
Polyurethane (PU) liquid membrane works best for metal roofs in Singapore because it cures into a continuous flexible film that handles the daily thermal expansion of metal panels without cracking. Acrylic elastomeric coatings are a lower-cost alternative for less-exposed roofs. Bituminous tape is used to reinforce seams and overlaps before the full topcoat is applied.
Can rusted metal roofs still be waterproofed?
Yes, rusted metal roofs can still be waterproofed if the corrosion is surface-level and the underlying panel is structurally sound. The process requires mechanical wire-brushing or sandblasting to remove loose rust, followed by a rust-converter primer, then a flexible waterproofing membrane. Severely corroded panels with through-holes need replacement before any coating is worth applying.
How long does metal roof waterproofing last?
Metal roof waterproofing in Singapore typically lasts 8 to 12 years when polyurethane (PU) liquid membrane is properly applied over a clean, primed surface. Acrylic coatings on metal sit lower at 5 to 8 years. Lifespan drops sharply if seams are not reinforced with bituminous tape or fibre mesh before the topcoat. Annual inspections catch early failures.
Is silicone or polyurethane better for metal roof waterproofing?
Polyurethane (PU) is the better default for metal roof waterproofing in Singapore because it bonds well to most primers, handles thermal movement, and costs less than silicone. Silicone outperforms PU on UV resistance and ponding water tolerance, making it preferred for low-pitch metal roofs with persistent wet spots. Silicone is more expensive per square metre and is harder to recoat later.