The short answer
They can be, if they are specified carelessly. A slim metal frame holding one large pane gives rain a stiff, light surface to strike, and a cottage bedroom below it has little to soften the sound. A laminated inner pane, good seals and a properly packed opening usually bring it down to a soft patter that sits under the kettle and the radio.
What is happening when rain hits the glass
Rain is not loud by itself. What you hear is the glass and frame turning each impact into sound and passing it into the room.
A raindrop striking a pane makes the glass flex a tiny amount. The pane is thin compared with a wall, and it is held in a frame that is also thin. A conservation rooflight is made that way on purpose, to keep the slim look of an old cast iron unit. The trade-off is that there is less material to absorb the movement. A heavy downpour is thousands of small taps a second, and a single large pane acts a little like a drum skin.
The same thing happens on any roof glazing, but a conservation rooflight has two features that make it easier to notice. The pane is often large and unbroken, because the design is one clear sheet of glass in a slim frame. And the room below is often an old one, a loft bedroom or a landing in a cottage, with bare boards, plaster and little soft furnishing. Hard rooms carry sound further, and a room that is otherwise quiet makes rain stand out.
What you actually hear, and where it comes from
Noise from a rooflight is seldom one thing. It helps to separate the sources, because each has a different remedy.
| What you hear | Usual cause | What changes it |
|---|---|---|
| A bright, tapping drum | Thin outer pane, no damping | Laminated pane |
| A rattle or buzz | Loose fixing or worn seal | Sound packing, new seals |
| A tick as it cools | Frame moving with heat | Correct fixings, expansion gaps |
| Dripping near the frame | Water off the roof edge | Flashing and upstand detail |
Only the first is about the glass. The others come from how the unit is fixed into the roof, which is why fitting matters as much as the product on the order form.
How a laminated inner pane calms it
Laminated glass is two sheets bonded with a clear plastic interlayer. That interlayer is the important part.
When the outer sheet is struck, the interlayer absorbs some of the energy instead of passing it straight through. Acoustic laminated glass uses a specially formulated interlayer that is better at this than the standard kind. In a sealed unit, the usual approach is to keep the outer pane as it is and set the laminated pane on the room side, so the drum effect is damped before it reaches the ceiling. Glass thickness and the cavity between panes also change how the unit responds, and the two panes are often deliberately chosen at different thicknesses so that they do not ring at the same pitch.
We do not quote figures for any of this. The right build depends on the room, the size of the pane and what the room is used for. Our page on quieter glazing for conservation rooflights goes further into the choices, and the one on laminated glass in a conservation rooflight covers what the glass looks like from outside.
If you are comparing units, the question about double glazing in conservation rooflights is worth reading first. A sealed double unit is a better starting point than a single pane for quiet as well as for warmth.
The frame, the seals and the opening
A well-chosen pane can be let down by the way the frame is fixed.
Steel frames are slim and strong. Aluminium frames are lighter and can be made in slim sections as well. Each behaves differently when struck and when it warms and cools, and the comparison of steel and aluminium conservation rooflights covers the trade-offs. Whichever you choose, the frame should be fixed to a sound timber upstand or trimmer, not simply pushed into the gap between rafters.
Seals matter because a gap is a path for sound. A continuous gasket around the sash, and a bead of sealant where the frame meets the structure, stop the small whistles and ticks that people mistake for rain noise. Around the edge of the opening, the space between the frame and the rafters should be packed with dense insulation, not left hollow. A hollow cavity acts like a sounding box.
The way the unit sits also affects how much water runs off near it. A flush fitting conservation rooflight sheds water straight onto the covering, and the flashing is fitted so that it runs away quietly. A raised upstand that is poorly finished can make a dripping sound at the edge.
Choosing for the room, and writing it down
A quiet result comes from deciding the build before the order is placed.
At the survey we stand in the room and look at what it is. A loft bedroom in a 1930s house, a cottage landing, a kitchen, a home office: each asks for something different. We note the size of the pane, the roof covering and how hard the room is. We also listen, because a room on a road or under a flight path is asked to do more than one in a quiet lane.
That choice is written into the quiet spec that comes with every quote. It names the glazing build, the seals and how the opening is packed, so that the unit you are quoted is the unit that arrives. You can see what it contains on the quiet spec page.
Fitting is part of the answer too. The work is installed to current Building Regulations, we handle the Building Control notification where the work is notifiable, and the workmanship carries a 10-year guarantee. To start with a survey, use the quote form.
Rain noise questions on an older roof
Will a conservation rooflight be louder than a standard roof window?
Not necessarily. It depends on the glazing build, not the label. A standard unit with a basic pane can drum more than a conservation unit built with a laminated inner pane. Our page on the difference between a conservation rooflight and a standard roof window compares them.
Does a slate or tile roof change how it sounds?
A little. A heavy roof covering and a well-packed opening reduce the overall sound from the roof, and the glass is then the part you notice. The glazing build is still the main lever.
Can I upgrade the glass later?
The sealed unit can be replaced in the same frame in many cases, which is a good reason to choose the frame carefully first. The survey shows whether yours can.
Where can I read more about the product?
Begin with the parent page on conservation rooflight installation.