Are wooden venetian blinds good at keeping out the sunlight for a bedroom? Is it best to go for 25mm, 35mm or 50mm or are they all similar?
Keeping out the sunlight
The bigger the slat size the less light will shine through the blind i.e. less overlapping slats, so 50 mm slats will give the best effect for light block, with the slats tilted in the upwards position.
As a guide approx 70% light block, what you could also do if you like the effect of Venetian Blinds but have concerns on the light issue, would be to mount a blackout Roller inside the window first then mount the Wooden Blind in front, it really depends on how much light you need blocked out.
To do this you would need to allow 40mm for the roller bracket and either 46mm for 25mm & 35mm slat brackets or 66mm for the 50mm slat bracket. Plus your window handles if they stand proud of the window frame.
So for a 50mm slat your window reveal would need to be 15.2cm in depth to fit both blinds with in the recess, allowing 40mm for handles! If your window is over 2mt check the bracket dimensions on the Roller Blind Info page for different bracket sizes dependant on the Roller Blind width.