Bedroom Blinds: Blockout Roller Blinds, Edge Gaps and Light Control
A bedroom blind needs to darken the room, including at 6am in December. Blockout fabric stops light through the panel, while side channels or an outside mount reduce light around its edges. Check both the fabric and the mount when choosing.
Light gaps at the edges, not the fabric
Check edge gaps before replacing blockout blinds that leave the bedroom too bright. An inside mount needs clearance so the fabric can move past the reveal, and that clearance is where the morning light gets in.
Blockout describes the fabric, not the whole product. How dark it gets at night depends on that fabric and on how the window blind is fitted around the opening.
Aluminium side channels and an outside mount
Blackout options for a bedroom come down to three ways of fitting the same fabric.
- Inside mount: The blind sits in the recess. It looks neat, and thin lines of light show at both edges.
- Outside mount: The blind sits on the wall above the frame and overlaps the opening on each side, so less light gets past the edges.
- Side channels: Slim channels run down both sides of the window and hold the fabric edges, closing the side gaps.
The price moves with the window size, the fabric grade, the mount and whether you add side channels.
A nursery or a room used for daytime sleep
A nursery used for daytime sleep often needs side channels and a pelmet as well as blockout fabric. Check the light at the sides and top of the blind. Keep operating cords and loops away from the cot; cordless or motorised controls remove the hanging operating cord.
Heat from a west-facing window
A bedroom facing afternoon sun can hold heat past bedtime. Compare a light-coloured or reflective-backed fabric with a dark blockout for that window. The fabric backing and the gaps around the blind affect the result.
Some homes hang blockout blinds and curtains on the same window. The blind sits close to the glass and the curtain closes over it at night.
Fauxwood and PVC slats where full dark is not the goal
A spare bedroom or a study corner can do without blackout. Faux-wood Venetian slats, which are PVC or composite, tilt for light control, letting daylight in at an angle while keeping the bed out of sight from the street. Closed slats still let some light through, so keep them for a study rather than a sleeping space.
Day-night blinds give privacy with their solid bands, but that fabric is not blackout, so the window stays dim rather than dark. Where a sliding door opens onto the garden, a vertical blind draws its vanes aside so the door stays usable.
The guide on how to choose blinds by room covers the rest of the house; the guide to living room blinds covers glare and evening privacy.
| Set-up | Darkness achieved | Best for |
|---|---|---|
| Blockout roller, inside mount | Dim: light lines at both edges | Adult bedroom, night sleep only |
| Blockout roller, outside mount | Dark: edges overlapped 50–100mm | Most bedrooms |
| Blockout roller + side channels | Very dark: edges closed | Nurseries, shift workers |
| Blockout Roman blind | Dark: softer look, same fabric grade | Main bedrooms wanting a curtain look |
| Day-night blind | Dim at best | Bedrooms that double as a day room |
Products mentioned in this guide
Blackout Blinds
Blackout blinds are blinds made from an opaque, coated or tightly-woven fabric that stops light passing through, for…
Roller Blinds
Roller blinds are a single panel of fabric that winds onto a tube above the window.
Roman Blinds
Roman blinds are fabric blinds that draw up into horizontal folds and stack at the top of the window.
Request a quote
Send your details with the form, or message Capetown Blinds on WhatsApp.
Questions about dark rooms and light gaps
What blinds are best for a bedroom?
Blockout blinds, fitted with an outside mount or side channels. The fabric stops light through the panel, and the mount or the channels handle the light at the edges.
Why is light coming in around my blackout blind?
Because an inside-mount blind has to sit slightly clear of the reveal to move freely, which leaves a few millimetres each side. That gap reads as a bright line at sunrise. An outside mount reduces light leakage through overlap, and suitable side channels reduce the side gaps further. How dark it gets still depends on the reveal and the fit.
What blinds are safest for a nursery?
Cordless or motorised, with no accessible loop of any length. Beyond safety, a nursery usually needs side channels and a pelmet, because daytime sleep is a much harder darkness standard than night-time sleep.
Do blackout blinds keep a bedroom cooler?
Yes, partly. A blockout blind stops direct sun reaching the room, but a dark fabric inside the glass absorbs heat and re-radiates it. In a hot west-facing bedroom, a light-coloured or reflective-backed fabric keeps the room cooler than a dark one of the same blockout grade.
Are day-night blinds dark enough for sleep?
No. The solid bands give privacy, but day-night fabric is not blackout. Choose a blockout fabric with an outside mount or side channels where it has to be dark for sleep.