On 29/01/2020 09:58, Tim Lamb wrote:

While we are here... has anyone found an easy way of stopping horizontal
vent flaps rattling in windy weather?

I stuck a length of type D draught strip
(http://preview.tinyurl.com/v695nlf) along the bottom of the back of
each flap. It doesn't stop them from flapping about but does reduce the
rattling noise.