VELUX blackout blinds offer 100% blackout of light through the fabric only. Whilst this means that the fabric will stop the vast majority of light entering the room, a small amount of light may creep around the blind construction, which is some cases is normal. However, if an excessive amount of light is entering around the blind frame, there may be installation issues preventing the blind from sitting correctly within the window sash.

The blind must be recessed back far enough into the sash to allow a tight connection between the sash and the blind side channels. When installing the blind, there should be a noticeable 'click' to indicate the blind cassette is located correctly. You also will not feel any gap between the top cassette and the sash.
Check the alignment of the side channels to the top cassette. This mitred connection must sit flush, with no visible gap. If this is the case, please refer to your products installation instructions for advice on how to remove and refit the side channels.
Please also ensure that the bottom installation brackets, have been located correctly within the sash. The small 'hooked' edge should line up and sit within the rebate on the front face of the sash. If this is sitting too far forward or backwards, please relocate this clip correctly.
Ensure the blind is pulled down fully, to ensure light tightness at the bottom. The blind is fitted with a small brake mechanism within the side channel, making the last 3-4cms of travel stiffer to operate. Please ensure the control bar is pushed down tightly, and you should feel a slight 'click' into position when the control bar is fully down.

If you are still experiencing light coming through your blind please contact VELUX Support by clicking here.

Light is coming through the blackout blind