How wide can a roller blind go?
How wide can a roller blind go? This is a common question from architects and interior designers when looking at large expanses of glazing and wondering how best to split the window treatments.
Typically on curtain walling and unitised facades, the blind width is chosen to match the mullion centres, however with advances in glass manufacture, it's now possible to make extra wide windows of 4m or more in a single pane. Should these be covered with a single blind or split down into multiple units?
Although we can manufacture blinds up to 6m wide for special applications, we recommend 3m as a maximum width for standard roller blinds.
There are a few reasons why we don't recommend blinds wider than this...
Fabric width
This is generally the main factor governing max width. The majority of raw materials for commercial applications are manufactured at 3m wide. For the domestic/residential market, many fabrics are only 2m wide. It is normal practice to cut the width of the roller blind from the width of the material, so the material width is also the maximum blind width.
If you need a blind that is wider than the raw material then you can cut the blind the other way round i.e. cut the blind width from the length of the material (known in the trade as railroading). Not all fabrics are suitable to be cut this way round as the warp threads (threads along the length of the material) are under tension during manufacture, and using these threads in a horizontal direction can make the edges of the blind curl inwards which doesn't look great.
Also bear in mind that if your windows are also more than 2.7m high then the blinds will require a horizontal join in the fabric. Joins don't show up too much in solid blackout fabrics but in a translucent fabrics they appear as a 'dark band' across the blind due to the double thickness material at this point.
With roller blinds, it's not possible to have a vertical join in the fabric as the additional thickness of joined material would affect the blind when it rolls up and cause creases in the fabric.
Tube size
The wider a blind is, the bigger diameter the roller tube at the top needs to be. If the roller tube is undersized for the blind width then you get bow-shaped ripples or "smiles" in the blind which don't look very attractive.
The SyncroShade and Decor 370 systems use a reinforced 52mm diameter tube to avoid this effect, which works for blinds up to 3m wide. For blinds over 3m then the roller tube size is calculated on a deflection calculator, and can be anything up to 150mm diameter. Before you choose a really wide blind, it's worth finding out the tube size and thinking about what this will look like in the context. Also if you are planning to conceal the roller inside a recessed blind box, then you will need to ensure you have a large enough box, and enough space above the ceiling.
Ease of use
For manual bead-chain operated blinds, once you get above 2.5m wide, the blind becomes quite heavy to raise. Consider specifying motorised blinds in these situations. If motorised is not practical then a counterbalance spring inside the blind should be used, or choose crank handle operation with a reduction gearbox.
Access to site
For large multi-storey projects this can be a significant factor - if the blinds are too long to fit in the lift, it can mean a lot of manual handling, with increased risk of injury and damage when getting the blinds to their location.