Pleated and cellular blinds guide

What are pleated and cellular blinds?

A pleated blind is related to the roller blind, but its fabric is pre-folded rather than wound on a tube and stacks like an accordion. In a cellular blind two pleated layers join to form honeycomb-shaped air pockets ^[1][2][3].

A single-layer pleated blind looks similar from the front but has no air pockets, so its insulation is more limited ^[3]. The air cushion between the layers of a cellular blind improves insulation and room acoustics ^[1]. Cells come in single, double or triple rows ^[2].

Mounting types

There are two main systems: tensioned blinds held by side tension cords and free-hanging blinds with a fixed top rail and a free bottom rail. Tensioned blinds can be fitted to the window sash and run top-down and bottom-up ^[1][6][2].

We recommend mounting on the ceiling line when the blind is layered with sheers and curtains: blinds are the layer closest to the glass, with sheer and curtain in front. If the blind should open with the sash, tensioned sash mounting is practical. Pleated blinds can also run bottom-up ^[1]; for example, to give privacy at the bottom while letting light in at the top.

According to one retailer’s guide, no-drill clamp mounting only works on inward-opening PVC or aluminium windows with a seal on the inner side, and the frame thickness the clamp can take is limited ^[8][9]. Roof windows use systems with side guide rails, and conservatory roofs use ceiling systems with steel tension wires ^[1][7][6]; pleated blinds are designed for heated indoor rooms; for pools or greenhouses, ask the maker ^[6].

Fabrics, light and heat

A fabric reflects, absorbs and transmits part of the light; absorbed light mostly turns into heat. Translucent, blackout and reflective-coated fabrics therefore affect a room differently ^[6][4].

Some cellular blinds carry a low-emissivity (low-e) coating inside the cells, which reflects thermal radiation and improves insulation ^[4][10]. Day-night models combine two fabrics (for example translucent and blackout) in one system ^[1]. The European standard EN 14501 classifies visual comfort ^[11].

How to measure

Measure in several places with a metal tape; the order size depends on the mounting type and differs between makers. Follow your own manufacturer’s measuring guide before ordering ^[15][8][9].

As an example, one guide deducts 5 mm from the width for mounting inside a flat glazing bead ^[8]; for sash mounting the fabric overlaps on each side, and for wall mounting a wider overlap plus the stack height is added ^[9]. Glazing-bead mounting needs enough rebate depth in the sash ^[15]. Check that handles and fittings do not block the blind ^[8].

Insulation: how effective?

Cellular blinds are generally regarded as having the highest thermal resistance among window coverings; the US Department of Energy says that, tightly fitted, they can cut window heat loss in winter by 40% or more, equal to about 10% heating energy savings ^[5].

The result depends on use and climate: one field test found no significant average saving in winter under typical daily use (some blinds open, some closed) compared with no blinds ^[12]; another field study showed rated cellular blinds saving up to 24% heating energy compared with generic blinds ^[14]. Modelling studies also vary by climate ^[10]. These data come from US homes.

In the US an independent programme (AERC) rates the energy performance of window attachments; look for such independent ratings when energy savings are claimed ^[4][13].

Child safety

Blind cords and chains are a strangulation hazard for young children, especially under 3; since September 2014 European standards require all internal blinds to be made so as to limit this risk ^[16][18].

The EU decision requires breakaway or cord-hiding safety devices where design cannot prevent loops, and height alone is not counted as safety ^[17]. One manufacturer puts the cord exit at least 150 cm above the floor and supplies systems with a safety tassel ^[6]. Even blinds that look cordless can carry inner cords between the fabric layers ^[19].

Care and cleaning

For dust, lower the blind fully and use a soft brush or low-suction vacuum; washing depends on the product; one maker’s instructions exclude coated blackout fabrics from washing. Your product’s instructions come first ^[20][6].

One maker allows gentle washing at no more than 30 °C with delicate detergent but excludes coated blackout fabrics ^[6]. One maker does not recommend chemical or ultrasonic cleaning ^[6]; other makers’ instructions may differ. To keep the pleats crisp, operate the blind regularly and do not leave it folded for long periods ^[6].

Relevant standards

The main European standards are EN 13120 (performance and safety of internal blinds), EN 16433 and EN 16434 for child safety, and EN 14501 for visual and thermal comfort ^{[21][16][22][11]}.

• EN 13120: requirements for internal blinds fitted to buildings; covers many types including pleated and cellular, not draperies ^[21].
• EN 16433 / EN 16434: test methods and safety-device requirements against strangulation hazards ^[16][22].
• EN 14501: visual comfort (darkening, night privacy, glare control) and thermal comfort classes ^[11].