Why a light roof is a loud roof
When a raindrop hits a sheet, the sheet flexes a tiny amount and springs back. That flex pushes the air on the underside, and pushed air is sound. A thin, light sheet flexes more for each drop than a thick, heavy one, so it passes more of the hit through to you.
Multiwall polycarbonate adds a second problem. The flutes inside are long, narrow air chambers, and they ring a little when struck, like blowing across a bottle. Ribbed sheets, with their tall corrugations, catch the rain at an angle and rattle along their length. Glass is heavier and quieter in steady rain, though big drops and hail still ping off it.
The room itself joins in. Hard floors, bare glass walls and almost no soft furniture mean nothing soaks up the sound once it is inside, so it bounces about.
Is it the rain, or something loose?
Not every noise is rain. Before you blame the material, rule out the fixable faults, because a few are cheap and quick.
Listening for the cause
- Drumming everywhere at onceThe whole roof hums evenly in a downpour. That is the sheet material itself.
- A tap in one spotA steady drip from a gutter, a branch or the house roof landing on the same place. Find the source outside.
- Clicks on sunny daysSheets expanding and sliding against their bars as they heat. Often a sign of tight or dry fixings.
- Rattling in windA loose cap, end closure or ridge piece. A competent fitter can usually tighten it.
- Creaks at nightThe frame cooling and shrinking. Normal in small doses, worth a look if it is new.
Cheap ways to soften the sound
- Stop the drips from above. If the house roof or a full gutter is pouring onto one spot, clear the gutter or fit a short diverter, and that one loud tap goes.
- Add soft things. A big rug, a fabric sofa, curtains on the glass walls and cushions all soak up the echo. They do nothing for the sound coming through the roof, but the room stops ringing.
- Fabric blinds under the roof. Pleated blinds take some sharpness off the noise. They also gather dust and do very little in a hailstorm.
- Trim overhanging trees. Branches drop big, heavy drips long after the rain has stopped.
Some people fit an insulation kit inside the old roof. It adds weight and softness under the sheets and helps with noise, though it leaves the old roof outside to age. We compare the two honestly in an insulation kit or a new roof.
How the panel roof deals with rain
The panel is a sandwich. Aluminium skin, 75 mm of dense insulating foam, aluminium skin. The foam is glued to both skins across the whole surface, so the top skin cannot flex on its own, and the hit from each drop is spread into a thick, heavy slab that barely moves. With no hollow chambers inside, there is nothing to ring.
We have not measured our roofs with a sound meter, so we will not quote decibels at you. Expect a downpour to reach you as a low, soft patter, closer to rain on the main house roof than rain on a tent.
The panels also do the job you probably came for, which is temperature. Our Comfort Calendar shows the summer hours above 25°C falling from 1,320 to 317 under the same roof swap.
Multiwall polycarbonate
- Light, thin sheet that flexes with each drop
- Hollow flutes that ring when struck
- Hard rattles on ribbed profiles
- Hail sounds like gravel on a tin
75 mm panel roof
- Heavy foam core bonded to both skins
- No air chambers to resonate
- Heavy rain arrives as a low patter
- Smooth white ceiling inside
What you will still hear
The walls are still glass, and glass carries sound. A storm hitting the side windows is the same storm it was before. A roof light, if you choose one, is glass too, and rain on it sounds like rain on a window. Hail on a metal skin makes a muffled knock rather than silence.
So think of the result as a room that sounds like the rest of the house in bad weather, not a recording studio. If roof lights matter to you, keeping them small keeps the quiet.
Sizing up a quieter roof
Most rooms take a day or two of work, and the old sheets leave with the fitters. Our guide prices start at £3,000 for a small room, and you can read what the work looks like on the fitting day page. When you are ready, start a quote for a free survey.
