Is a Metal Deck Roof Noisy When It Rains?

Why metal roofs get a noisy reputation

Anyone who grew up near a zinc-roofed kampung house or a factory canopy knows the sound: a thunderstorm on bare metal is loud enough to stop a conversation. That reputation sticks to every metal roof, but a residential metal deck roof is a different product.

Noise comes from raindrops hitting a thin, hard sheet that vibrates and has nothing behind it to absorb the sound. Remove the empty space and add mass and damping underneath, and the sound drops a lot.

Plain metal vs PU-foam metal deck

This is what changes when the sheet has a PU foam layer bonded to it.

What makes a metal deck roof quiet

Noise control is a system, not a single product. These are the layers that matter, from the outside in:

• PU foam bonded to the underside of the sheet, which dampens vibration and insulates
• Aluminium foil facing, mainly for heat but part of the build-up
• The roof space itself, a buffer between the roof and your rooms
• The plaster or gypsum ceiling below, which blocks a large share of remaining sound
• Properly fixed sheets and screws, since loose fixings rattle in wind and rain

How it compares with tile roofs

Be realistic: a PU-foam metal deck will still be a little more audible than heavy concrete tiles during a heavy downpour. Most owners describe it as a steady soft rain sound rather than drumming, and many stop noticing it after the first few storms. If absolute quiet is the priority, stone-coated interlocking tiles (RM18.50 to RM25 per sq ft, 20-year warranty) or concrete tiles are the quieter options.

For a bedroom directly under the roof in a double-storey terrace, the ceiling matters as much as the roof. A house with a sound ceiling and PU-foam metal deck is usually comfortable even in an October Klang Valley thunderstorm.

Already have a noisy metal roof?

If you have an existing uninsulated metal or zinc roof, maybe over a kitchen extension or a converted car porch, you have two routes:

• Add insulation under the existing roof if the sheets are in good condition. See roof heat and sound insulation. Priced after inspection.
• Replace with PU-foam metal deck if the sheets are rusted, leaking or the screws have failed. At RM14 to RM22 per sq ft, a 300 sq ft extension roof is about RM4,200 to RM6,600.

Worked example: kitchen extension

A common case on terraces is a rear kitchen extension roofed with plain metal sheet. It is loud in rain and hot in the afternoon.

Extension 20 x 15 ft is about 300 sq ft of roof. Replacing it with PU-foam metal deck at RM14 to RM22 per sq ft gives roughly RM4,200 to RM6,600, excluding any truss or rafter work. If the extension roof is steeper than 30 degrees, add about 15%. The exact price is confirmed after inspection, including the flashing where the extension meets the main house wall, which is a frequent leak point.

Other noises that are not rain

Sometimes owners call about roof noise that turns out to be something else:

• Ticking or creaking in the late afternoon: thermal expansion as sheets cool
• Rattling in wind: loose sheets, flashing or screws
• Scratching or scurrying: rats, birds or bats in the roof space
• Water dripping inside the ceiling: a leak, which needs roof leak repair

Hear the difference before you decide

Our technician can explain how a PU-foam metal deck would perform on your house, check your ceiling and truss, and give you a quotation on the spot. All prices are indicative; the exact price is confirmed after the free inspection.

Read more on PU foam metal deck roof and heat and sound insulation, or book a free inspection.