Dim-Out Blinds Product Characteristics

The window behind the blind should not be left open if the blind is in the lowered position as this can create a vacuum that can suck the fabric out of the frame of the blind.

Where the blind is bigger than the available width of the fabric, the fabric will need to be joined or turned. With multiple blinds, the pattern on the fabric may not match adjacent blinds and may not be centralised on the blind. The fabric might not appear totally flat. There may be rippling to the sides or ‘V’ shaped ripples and this is due to the fabric being secured on all edges but expanding and contracting as temperatures change.

There will be some gaps where the headboxes of the neighbouring blinds butt against each other. As the blinds use side channels in which the cloth runs, there should be no exposed glass but the channels may not abut each other on adjacent blinds.

Blinds fitted inside a reveal may require either a timber frame or packer to ensure it is fitted square. To ensure a seal against light ingress between the edge of the reveal and the frame of the cassette, either expanding foam, caulk or mastic may be used.

A cassetted roller blind must be fitted square, however in reality reveals are often not. The head of the window or sill may not be level and the distances between the side walls throughout often vary. The distance from the edge of the reveal to the window may also vary, so blinds will either be fitted to run parallel to the window or to the edge of the reveal. 

Cassetted dim-out blinds have a housing at the top of the blind, channels to either side and sometimes a bottom channel and/ or a heavy bottom bar with a light seal strip. Fitted with a blackout fabric, this blind style will provide the highest degree of dim-out of any blind, especially if fitted outside the reveal as this typically improves the level of dim-out. However, cassetted blinds are not 100% blackout as there will still be a very small amount of light ingressing around the side channels and possibly other areas.

There is a wide range of motorised solutions available for your comfort and convenience and each system will have its own characteristics. Some points to consider are: 

• Speed and alignment: Blinds in the same installation may not travel at the same speed and may not line up if stopped during the travel of the blinds due to mechanical and electrical tolerances.

 • Noise: Being operated by a motor, some noise will be emitted. Quiet motors may be available. 

• Wiring: Some surface wiring may be required. Where 240V mains power is involved, a competent person will be required to provide a power feed unless the blinds can be powered from a plug inserted into an existing socket. 

• Motor protection: 

For safety reasons, most motors are fitted with a thermal cut-out to protect them from getting too hot (usually from over-use). When cooled sufficiently, the motor will start working again.

Where a smart home hub is used the signals to the blinds may get occasionally interrupted by other wireless devices in the home such as smart speakers or doorbells. This can affect the operation, or seamless operation of the blind.

All blinds with cords or chains could pose a risk of strangulation to young children. The BBSA recommends inherently safe products (Safe by Design). If you choose a product with additional child safety devices, these must be securely fitted as required. For further information on window blind safety visit: www.makeitsafe.org.uk