should i insulate air bricks in upper floor flat ?

hi, I have a 1st floor flat in a converted house, has 2 air bricks, both of which are surrounded by mould.

my theory is they create cold points that water vapour condenses on.

I know houses are supposed to be ventilated but its obviously causing mould, so im thinking of either stuffing some rockwool in to cut it down, or completely block up ?

is that a good idea ?
thanks

 

When open coal or gas fires were common, it was essential to have rooms well ventilated to replace the air burnt in combustion, so houses were built with these vents. If your heating systems are now all room sealed, then no special ventilation is needed on that score.

If you also make a point of not drying clothes in the house, not having open pans boiling away on the stove, use an extractor hood extracting outdoor, have an automatic fan in the bathroom - then it is worthwhile blocking all of the air bricks up.

 

Ventilation prevents mold, they are not the cause.