However neat, fabric joins in roller blind fabrics will always be visible to the discerning eye. As glazing in offices and high-end residential apartments gets bigger in width and height, fabric joins are begrudgingly accepted as the norm. This blog sets out typical size parameters for roller blinds without fabric joins.
Roller blind fabrics typically range in width from 1.8m – 2.5m and are 30m in length. Therefore, the restricting factor is the fabric width.
the width of the blind is 100mm less than the width of the fabric,
the drop of the blind is 300mm less than the width of the fabric,
your blinds will not require a fabric join.
This assumes that the fabric is ‘non-directional’ i.e. can be used either vertically (as it comes off the roll) or on its’ side.
The wider the roll of fabric, the more scope you have to produce blinds without joins. A 2.5m wide fabric allows you to make a roller blind without a join up to 2.4m wide with no restriction on the drop. There are some 3.0m wide fabric rolls which allow blinds up to 2.9m wide.
In a commercial office or residential apartment with glazed curtain walling the floor to ceiling, glazing is typically 2.7m high with mullions spaced 1.5m apart. It is common practice to ensure blinds align with mullions to reduce light leakage. By using a fabric ranging from 1.8m – 2.5m in width, blinds either have to be restricted to a 1.5m width (incurring significant fabric wastage) or, if a single blind is to span two mullions have a join in the fabric.
However, using a 3m wide fabric allows blinds to be made at 3.0m wide to span two mullions with the only restriction on the drop being the maximum weight the roller blinds hardware system can manage.
3m wide width fabrics
Betascreen 90 is a screen fabric used in offices and is available in a 3.0m width. High performance metallised screen fabrics to reduce heat and glare, such as Verosol Enviroscreen, are now available in 3.1m width. If a high degree of room darkening is required, then ThetaBlock 40 is available in a 3.0m width.
Quality of fabric join
If fabric joins are unavoidable, ask the manufacturer for a sample. Some manufacturers are known to stitch fabrics together, other heat welders leave a 5mm shiny strip on the fabric. Waverley have just invested in the latest welder, which produces the closest thing to an invisible join there is available.
As well as looking at the performance criteria of roller blinds fabrics when specifying blinds on commercial or high-end residential projects, take note of the width of the fabric as this will determine whether or not the roller blinds will require joins.