Does a blind make a skylight quieter in rain?

A blind works on the room side of the glass. The drumming is made on the outside, so a blind can only soften what has already come through.

Rain strikes the outer pane, and the pane vibrates. That vibration crosses the cavity, reaches the inner pane and leaves it as sound. By the time the noise is in the room, a blind has no way to stop it being made. What the blind does is sit in the path of the sound and absorb a little of it, the way a curtain does at a window.

How much it absorbs depends on the fabric and the fit. A thick pleated or honeycomb blind that sits close to the glass takes the edge off the high, tapping part of a downpour. A thin roller blind stretched flat does almost nothing for sound, because there is no depth in it to soak anything up. A venetian slat blind can even add a faint rattle when the wind moves it.

So a blind changes the feel of the room more than the level of the noise. Under a bare pane the rain can sound bright and close. Under a blind the same rain sounds a little duller, and the room feels less exposed. That is worth having. It is just not the same as a quieter rooflight.

Four parts of a rooflight decide how rain sounds, and none of them is the blind.

The first is the glass. A unit made of two toughened panes of equal thickness tends to ring, because both panes move in step and nothing in the glass damps them. A laminated inner pane has a plastic interlayer bonded between two sheets, and that layer takes the energy out of the vibration. Our explanation of acoustic laminated glass for rooflights goes through how the interlayer works.

The second is the outer pane. Heavier glass moves less when a drop lands on it. Pairing a thicker outer pane with a different inner pane also stops the two resonating together.

The third is the seals. A unit that sits loosely in its gasket can buzz against the frame in heavy rain. The fourth is the upstand, the raised kerb the frame sits on. A thin or hollow one acts like the body of a drum. A dense, fully insulated kerb gives the frame something solid to rest on.

Those four are what we write into the quiet spec that comes with every quote. A blind appears there only as a finishing choice for the room, never as the answer to the noise.

The two do different jobs, and it helps to see them side by side.

The last row is the one that matters for planning. A blind can be fitted at any time, so there is no rush to decide. The glass is different. Once a unit is in, changing its build means replacing it. That is why the glazing decision comes first and the blind comes after.

If you want a blind to do some quiet work as well as the darkening, a few choices matter more than the brand.

• Depth. A honeycomb or pleated blind traps a layer of air and soaks up more than a flat roller.
• Fit. A blind that runs in side channels, close to the glass, leaves no gap for sound to slip past the edges.
• Movement. Tensioned rails stop a blind flapping or ticking against the frame in wind.
• Room shape. In a loft bedroom with a sloped ceiling, a fitted blind also stops the glass acting as a cold, bright surface at night.

Most blinds for roof glazing are made for a particular size and type of unit, so they are ordered once the rooflight is chosen. On an electric or opening unit, check that the blind suits the mechanism before anything is bought. Our page on electric and opening rooflights covers what sits around the opening.

Some rooms under a rooflight benefit from a blind far more than others.

A bedroom is the obvious one. A loft room in a 1950s or 1960s house can have a rooflight over the bed, and a blind controls the early light as well as adding a softness that helps at night. If the room also hears aircraft, read our page on rooflights under the Gatwick flight paths, because that noise is a glass question too, and a blind will not answer it.

A kitchen extension with a flat rooflight is a different case. There the blind is mostly about glare and heat on a bright day. Rain noise in that room is better dealt with in the glass, and our guide on reducing rain noise under a flat rooflight sets out the build choices in order.

If you are not sure which side of the line your room sits on, we listen at the survey. We note what the room hears and when it is in use, and the quote says what we would specify and why. You can ask for that through the quote form, or start with the page on whether skylights are noisy in the rain. The full list of ways we cover the work starts on the main skylight and rooflight page.

Will a blind stop rain drumming completely?

No. It removes a little of the sharp top end and makes the room feel more enclosed, but the noise is still made on the outside of the glass. A quieter build is the only thing that changes how much is made.

Can I fit a blind to an existing skylight and expect it to be quieter?

You can fit one, and the room will feel softer. Expect a modest change in sound, not a transformation. If the unit is old, thin or loose in its seals, that is a reason to look at replacing the unit rather than dressing it. Our page on whether acoustic glass is worth it helps with that decision.

Does a blind help with a rooflight that has misted?

No. Misting means the seal of the sealed unit has failed, and a blind hides it rather than solving it. The answer is a new unit, which we cover under misted and failed rooflight replacement.

Should a blind be part of the quiet spec?

It can be listed as a finishing choice, with a note on fabric and fit. The spec puts the glass, the seals and the upstand first, because those decide the sound. Everything else follows from them.