Do these vents need blocking up?

[theprinceofdarkness]

This is a 1957 Council built bungalow with cavity walls and solid concrete floors. My one has 12 air vents along the front and two sides (none at the back) and I think they are not required. The cavities were filled with mineral wool fibre in the 1980s. These vents only go to the cavity - no underfloor ventilation, as solid. Having had a snoop around my neighbour's properties (unmodified), the houses only seemed to have one high level vent for the larder in the kitchen. One corner of our house has got a 9" square high and low level vents and two feet around the corner there is another 9" square low level vent there are also two more 9" X 3" low level vents within four feet.
On the modern extensions there are no air vents at all.
I don't know what people were thinking off when installed this lot but I think they all need blocking up.
Frank

 

[Nige F]

I know what they were thinking - The houses were for the Great Unwashed - one had to get some fresh air to these plebs somehow And ventilated cavity was a bona fide building technique @ the time . The 9x9`s should be lined across the cavity to provide air to the rooms - Maybe block those , leave the small ones that fed the cavity , they won`t hurt and the fill won`t get wet through them unless you get a flood higher than their level . Now wait for the Condensation Brigade to tell you I`m wrong ( they will). IF YOU HAVE A GAS FIRE/ BOILER you must get a Gas Safe engineer to advise before you block any vent to rooms they are in