Perches should be cleaned on a weekly basis as a minimum to help promote healthy chickens.
Special attention needs to be taken to the cleanliness of the perch to reduce the chances of any illnesses or injuries that they may sustain.
The chicken perch needs to be high enough off the ground to avoid draught (around 1 foot) but should be low enough for them to leap onto from the floor.
Your chickens should also be able to easily get down from the perch.