I've just recently moved in to a 1960 house and there is ventilation in every room via air bricks, but rather than plastic or metal vent covers they are made out of what looks like plaster but with strands of yellow straw. Just wondered if anyone had seen this before.
I'm planning to remove then as they are quite unattractive and replace them with other vent covers - but I guess it won't be any diffferent re lining etc??